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how do i polish the bolt?


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#61 Cobra's Custom LLC

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Posted 15 September 2010 - 04:18 PM

This one was taken way too far. The end of the bolt neck can even be seen turning inside the hole if seen up close.
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These pics are only being posted to show how easy it is to really screw up your bolt if you go at it and get too far down into it. Sure, it's repairable, but much easier to just get someone to do it that has done lots of them before and knows just what "too far" is.

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I can't believe this bolt isn't showing a similar hole. You can bet your ass it is paper thin though.....which is my major concern about taking them down "too far". Even if you can't see a hole, it can still be paper thin and end up breaking through if too much pressure is ever applied there, like by a steel hull or possibly a slug load.

In closing, a before and after of a safer mod.

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#62 Cobra's Custom LLC

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Posted 15 September 2010 - 05:07 PM

The polishing is what helps the closed bolt load, as it slips easier. You're always gonna have to push a little, even if you take so much off that you ruin the bolt.
If you propperly polish the right places, it creates a smoother action & trigger pull. One can not argue otherwise.


This is true, any areas throughout the whole gun, where you have metal on metal friction going on, can benefit by being polished. On a well worn in AK that's shot thousands of rounds, you can see where it has pretty much polished all these areas itself. It takes awhile though...when you have a finicky S-12 with, or without gas problems, it really pays to reduce all the friction possible early on. I prefer to do it by addressing the specific areas that need it, instead of just wasting a shit ton of expensive ammo trying to get the same results.

As far as having to push against the top round anyway, reprofiled and polished bolt or not....that's not the case in my guns. I just simply lock the front lug in the well, and rock it backwards. The smoothed, polished transition, and the lack of a "shoulder" for that top round to jam right into, allow it to rock in just like any AK rifle mag.

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#63 Diego-ted

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Posted 15 September 2010 - 06:27 PM

Cobra, well worth the $$ you charge. I was going to do it myself, but I can see it is better left to someone who can get all the benis for the effort. All I need is a time where I want to have my gun down for the time it takes to get the bolt to you and back.

Thx for all the info and pics!!
Diego


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#64 saiga tech

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Posted 15 September 2010 - 06:31 PM





That's a lot of metal coming off of there!! So the darkend area gets cut, rounded and blended?

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Nope. Cutting is done. Only bending and a light polish left.

Put your bolt up against the pic's to compare.

And yes there is a lot of material removed, It's hard to do this with abrasives.


Will do, I was looking at one of Cobra's bolts when I posted above, It looks like he takes way more off then what you did!

thx Ted


I acually remove more.

Hard to see but look at the area you highlighted

Not dinging anybody here....just info


Not trying to split hairs here but...
You say you remove more. That should be explained a little better. As you can see in the photos I've posted, the serial numbers are no longer visible for the most part, on the body of the bolt....but left completely intact on the bolt head. So on mine more was removed, just in a different place.
I do not like to remove quite that much on the shoulder of the bolt body, where right underneath you have the cavity the bolt head rotates in. If you do it gets very thin there. How many bolts have you seen ground, or milled through to this cavity yourself? I have a couple here that were taken too far, which is why I've been so outspoken about people not getting carried away with removing material.
As you know, the critical areas where the most problems arise on unmodded bolts, are the little shoulder where the shaft first widens into the fat part of the bolt (where the shell gets caught when trying to insert a full mag), the median ridge that runs between the to factory flats, and the overall thickness of the body, head, and stationary extractor claw (the areas that cause so much drag on the top shell in the mag when the bolt head has to turn and come back over the shell, under mag spring pressure. Having no sharp corners to increase drag, or thick unpolished areas to make it worse, is the whole idea....just some info for some who seek to understand more about why this mod is done.




You are showing the bolt after the machine work is done before any final blending.


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#65 Nailbomb

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Posted 15 September 2010 - 08:28 PM

I'm a garage hack with a dremil copying other peoples work.

Just sayin'
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#66 Cobra's Custom LLC

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Posted 15 September 2010 - 11:38 PM

Cobra as usaul you want to be the absolute athority and will spend hours trying to prove you are.



Oh now is that so...? Wow, thanks a lot Ray.... I suppose you are somehow more of an authority on the subject? That's like a slap in the face after I spent so much time and effort posting all that to try and help folks here. People have been asking for some before / after pics, so yeah I spent a few hours taking and posting some.
FWIW you're wrong, I was only using that pic you posted to illustrate an important point, because that angle showed the shoulder I was referring to, which is something many people mod their own bolts and don't remove. Anyone with any sense can see the bolt wasn't finished in that pic.
Funny how you didn't mind using my photo to express your own point about the way you remove more material.... I hope nobody tries to copy what you did and grinds a hole through their bolt.

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#67 S-12 Pauly

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Posted 24 September 2010 - 02:50 AM

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Also, unless one completely removes the bolt or has a BHO of some sort engaged, the shells MUST be pushed against the bolt (as you insert the front tab) before one can rock them in.
Yeah, it's easy, but shells press against the bolt, period.



I CNC the bolt and have it programed so there's no problem removing too much material.

Yes I have seen damaged bolts but can be easially repaired.

Do you need any of your bolts repaired?

Uhhh...

Actually, it's kinda a bitch.
When you weld on a tin-foil thin bolt (or carrier) you're gonna get some drip through.
For the carrier, a 9mm drill bit on your press & a lot of time is required, then you have to remove the scaling that develops during the weld on the inside of the hole.

The drip-through on the bolt is easier to remove & restore, but it's still a real bitch to add steel right & not screw up the hole that you push the pin through.
If you do screw up the hole, it must be re-drilled & that's another bitch to get just right.

I recently got done doing a set where a guy went so far it ruined the carrier & he made the bolt flat (nearly punching through) & I WILL NOT be doing it again.
It was a real PITA...
Don't offer, trust me.
If you do one you won't wanna do another.
Carriers are easier other than the drip through, but bolts are a bitch to rebuild.

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#68 saiga tech

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Posted 24 September 2010 - 08:01 AM

I don't mean to be argumentative, but this is enough to easily insert mags & be able to run dependably.

Posted Image


Also, unless one completely removes the bolt or has a BHO of some sort engaged, the shells MUST be pushed against the bolt (as you insert the front tab) before one can rock them in.
Yeah, it's easy, but shells press against the bolt, period.




I CNC the bolt and have it programed so there's no problem removing too much material.

Yes I have seen damaged bolts but can be easially repaired.

Do you need any of your bolts repaired?

Uhhh...

Actually, it's kinda a bitch.
When you weld on a tin-foil thin bolt (or carrier) you're gonna get some drip through.
For the carrier, a 9mm drill bit on your press & a lot of time is required, then you have to remove the scaling that develops during the weld on the inside of the hole.

The drip-through on the bolt is easier to remove & restore, but it's still a real bitch to add steel right & not screw up the hole that you push the pin through.
If you do screw up the hole, it must be re-drilled & that's another bitch to get just right.

I recently got done doing a set where a guy went so far it ruined the carrier & he made the bolt flat (nearly punching through) & I WILL NOT be doing it again.
It was a real PITA...
Don't offer, trust me.
If you do one you won't wanna do another.
Carriers are easier other than the drip through, but bolts are a bitch to rebuild.


Hey Paulyski

Thanks for the info


I have repaired bolts and when you have years ofexperience fabing, designing, and machining you will find a way

drip throughs. ie: brass plug. scaling....purge with argon ...... redrill the bolt?

Much easier to bore it on a lathe, interpolate in mill, or bore on mill don't you think.



I have had the fortune to learn my welding skills from a veteran indy car builder who grew up 1 block from the track.

In the 70's I worked on the persian 2 ICBM program, 80's MX ICBM and sidewinders, 90's FATS (firearms training systems),

Not trying to toot my own horn, I have consistantly tried to be humble on this board while others seem they think they are gods.

I recently had a very talented and well respected member here tell everyone he eye f@%ked his sights when installing and I'm thinking how is this statment going to help anyone? I'm offering sound information and this guy is having sex on his gun with his eye? And no one seemed to care.... oh well who cares

And by the way my bolts are not paper thin and It does help to profile as much material in the area's I pointed out. I also do not recommend anyone trying this at home without understanding there is a risk.

Again I apolagize if I come accross arrogant. I have tried very hard for years to praise people for trying new idea's and doing it themselves while others curse, belittle, constantly criticise on a regular bases


Also cobra I did not mean to minimalize or criticise your work. You have been a great inspiration to many on this forum.

As the wise man says be carefull going up you will meet the same people on the way down!!

Edited by saigatechusa, 24 September 2010 - 12:10 PM.

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#69 S-12 Pauly

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Posted 24 September 2010 - 03:23 PM

Hey Paulyski

Thanks for the info


I have repaired bolts and when you have years ofexperience fabing, designing, and machining you will find a way

drip throughs. ie: brass plug. scaling....purge with argon ...... redrill the bolt?

Much easier to bore it on a lathe, interpolate in mill, or bore on mill don't you think.

Please look closer, I did not say re-drill the bolt, with regards to the bolt, I was referring to the hole the pin goes through to hold the head to the body.
If this is pluged while adding steel it would be a bitch to re-drill perfectly & not slightly enlarge the rest of the hole that the pin goes through, thus loosening the pins fit.
Possible? Yes.
But still a real pain in the ass.
The bolt that I fixed was actually ground quite flat, as if the person profiling didn't realize it had to rotate.
It was kinda ridiculous.

I did however run a 9mm bit down the carrier to remove drip through where it was paper thin. They removed so much from the bottom, that it wouldn't reset the hammer. (which strangely enough wasn't profiled hardly at all)
It took so long because I didn't want to enlarge the hole, so it required slight pressure, otherwise the bit would have bored the hole oblong.


Also, okay, brass plug...
So you're gonna lathe out 2 brass plugs before welding?
Still a pain.

As for purging with argon, okay, take a second argon tank aside from the one on your TIG outfit & blow argon through a carrier hole while a brass plug is in there to avoid scaling?

Sure... Can be done... But it's still a real pain in the ass compared to doing it right the first time, which is the point I was making, thank you very much for reiterating this for me.

As for ease of loading on a closed bolt, I guess I just must have some magical technique that allows me to do this well on stick mags. I dunno, but I'll say again, they don't have to be perfectly flat to do so.


ETA;
Shannon, since nobody else has, for what it's worth, I will thank you for posting all the pics.
They will help others get ideas on how to not screw up.

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#70 saiga tech

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Posted 24 September 2010 - 07:03 PM


Hey Paulyski

Thanks for the info


I have repaired bolts and when you have years ofexperience fabing, designing, and machining you will find a way

drip throughs. ie: brass plug. scaling....purge with argon ...... redrill the bolt?

Much easier to bore it on a lathe, interpolate in mill, or bore on mill don't you think.

Please look closer, I did not say re-drill the bolt, with regards to the bolt, I was referring to the hole the pin goes through to hold the head to the body.
If this is pluged while adding steel it would be a bitch to re-drill perfectly & not slightly enlarge the rest of the hole that the pin goes through, thus loosening the pins fit.
Possible? Yes.
But still a real pain in the ass.
The bolt that I fixed was actually ground quite flat, as if the person profiling didn't realize it had to rotate.
It was kinda ridiculous.

I did however run a 9mm bit down the carrier to remove drip through where it was paper thin. They removed so much from the bottom, that it wouldn't reset the hammer. (which strangely enough wasn't profiled hardly at all)
It took so long because I didn't want to enlarge the hole, so it required slight pressure, otherwise the bit would have bored the hole oblong.
I unfortunately lack a lathe. Most of my steel that I fab with is 3/16ths or thicker sheet.

Also, okay, brass plug...
So you're gonna lathe out 2 brass plugs before welding?
Still a pain.

As for purging with argon, okay, take a second argon tank aside from the one on your TIG outfit & blow argon through a carrier hole while a brass plug is in there to avoid scaling?

Sure... Can be done... But it's still a real pain in the ass compared to doing it right the first time, which is the point I was making, thank you very much for reiterating this for me.

As for ease of loading on a closed bolt, I guess I just must have some magical technique that allows me to do this well on stick mags. I dunno, but I'll say again, they don't have to be perfectly flat to do so.


ETA;
Shannon, since nobody else has, for what it's worth, I will thank you for posting all the pics.
They will help others get ideas on how to not screw up.


Ok Paulyski I give up....I know not of which I speak of....................

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Edited by saigatechusa, 24 September 2010 - 07:04 PM.

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#71 S-12 Pauly

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Posted 24 September 2010 - 07:44 PM

Ok Paulyski I give up....I know not of which I speak of....................

Don't be mad, I think your work's great.
There's multiple ways to achieve favorable results.

The fact still remains that it's a PITA to rebuild bolts.
It just is.

Up until about 7 months ago, there were NO pics that were easy to find on the subject to help other DIY'ers profile them correctly.

I personally don't ever want to rebuild another after rebuilding one.
If you wanna do a tutorial, contact forum member "TheDudeAbides" first. He needs some steel added.
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#72 Tombs

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Posted 28 September 2010 - 06:54 PM

Just did this to my bolt with a stone wheel, wire wheel, dremel tool, wool wheel, and an electric drill with a rust remover pad.

It's about the smoothest surface I've ever felt in my life, smoother than glass. I had no idea what I was doing either.
It makes putting the drum in on a closed bolt a tiny bit easier but it's still a PITA. Time will tell if this causes less shell deformation. (I'm one of the unlucky few who own a saiga made before the BHO models.)


I don't see how someone could screw it up unless they just went crazy with it, and used way too aggressive of a bit to do the initial metal removal. Which you don't want to do in the 1st place because it'll be hard to polish afterwards.



This thread was a massive help, thanks!

Edited by Mephis, 28 September 2010 - 06:55 PM.

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#73 Ketzer

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Posted 29 September 2010 - 09:06 AM

I'm obviously a newb on here. I find everyones input valuable to help me learn. I can take in all the info and sort through the egos and determine for myself where the commonalities are. THANK YOU to everyone that posts, adds pics, argues technique.

I'm constantly amazed that with all the competeing alphas, you guys stay as civil as you do. :beer:


Jeff-
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#74 saiga tech

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Posted 29 September 2010 - 04:11 PM

I'm obviously a newb on here. I find everyones input valuable to help me learn. I can take in all the info and sort through the egos and determine for myself where the commonalities are. THANK YOU to everyone that posts, adds pics, argues technique.

I'm constantly amazed that with all the competeing alphas, you guys stay as civil as you do. :beer:


Jeff-


staying civil? I should show you the PM's I've recieved .......... :haha2: You wouldn't believe them :horror:

Edited by saigatechusa, 29 September 2010 - 04:15 PM.

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#75 S-12 Pauly

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Posted 30 September 2010 - 03:26 AM

I'm constantly amazed that with all the competeing alphas, you guys stay as civil as you do. :beer:


Jeff-

At first I was like, :mellow:


Then I was all, :huh:


Then, ^_^


But within seconds I was like; :haha2: :haha2: :haha2: :haha2: :haha2:


I'm obviously a newb on here.

Yup. ^_^

Welcome to the forum! :up:

Edited by Paulyski, 30 September 2010 - 03:31 AM.

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#76 Ketzer

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Posted 30 September 2010 - 10:39 AM

Oh I was lurking back during the drum wars... I know it can get nas-tee. Most guys seem to be able to stop just short of #@*&^!!! though. :angel:


Jeff-

#77 saiga tech

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Posted 30 September 2010 - 07:24 PM




Can just pulling the charging handle over and over polish everything where it needs to be polished? It is is already mirror-like on the edges that contact.

What Cobra said is correct.

It's not just about polishing, it's the re-profile too.
Knocking down the excess angles edges that move against the rounds reduces force needed to cycle the gun.
Kinda like if you were to try to roll a hexagon shaped ball, as opposed to rolling a circular ball.


I beg to differ....hand cycling does help with breakin polished or not. Anyone who is skeptical can try it themselves.

most people over polish and most surfaces they polish are not necessary.

The recontouring is more important than the polishing. There are thousands of these weapons used by the military without any polishing.

I'm not saying not to polish, I also polish but proper recontouring will give you the biggest performance gain.

The polishing is what helps the closed bolt load, as it slips easier. You're always gonna have to push a little, even if you take so much off that you ruin the bolt.
If you propperly polish the right places, it creates a smoother action & trigger pull. One can not argue otherwise.
If one were to sand down the bolt & leave it rough, there would be a rather large power loss.
As for all the military S-12s having nothing at all done... Well... I would assume they don't shoot cheap-ass bird shot too much in the Russian military.

My gun with 3 .09375 ports & a SLIGHTLY profiled highly polished bolt runs winchester (the lousiest I can find) birdshot like a raped ape & rarely EVER chokes... Even when I shoot it one handed.
It cycles the same shitty load reliably with the drum set to the correct (higher) spring pressure as one would have the drum set for high brass.
The gun with 3 ports @ 3/32 (.0975) is only warranted to shoot federal ammo, & on many guns, they won't properly cycle federal ammo without lightening the drum's spring pressure.
My end result is a gun that shoots with the utmost reliability, but will not cycle weak loads on setting 1, thus proving proper gas pressures.
I can't argue with perfection.

As for unnecessary areas, yeah,,, the whole carrier doesn't need to be a mirror & the top of the bolt that has no friction points are unneeded for performance.

I "advise to" tune every gun I "advise on"the same as mine & am experiencing the same results as mine.





Does anyone have a side by side pic of an untouched factory bolt vs. a re-profiled bolt. I want to re-work my bolt for closed bolt mag insertions, but I don't know how much to take it down... Thanks in advance.



This picture would be worth 10000000000000000 words!! Please!

Diego

Scroll up.
There's a whole rippin' dick-load of pictures of bolts.
Take a picture of your bolt for a factory pic.
Next time I tune a gun, I'll try to take a pic before hand.



Straight from IZHMASH website:

"The magazine can be charged with any twelve gauge ammunition - even 70, 73 and 76 mm long at the same time. The shotgun can fire both standard and non-lethal ammunition."

Edited by saigatechusa, 30 September 2010 - 07:25 PM.

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#78 Cobra's Custom LLC

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Posted 30 September 2010 - 07:57 PM

Like he said...who wrote that? Was it an American who has a walmart full of cheap ass shitty ammo down the block? Or was it a Russian who never even tried to choke his gun down with that crap?

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#79 S-12 Pauly

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Posted 30 September 2010 - 10:25 PM





Can just pulling the charging handle over and over polish everything where it needs to be polished? It is is already mirror-like on the edges that contact.

What Cobra said is correct.

It's not just about polishing, it's the re-profile too.
Knocking down the excess angles edges that move against the rounds reduces force needed to cycle the gun.
Kinda like if you were to try to roll a hexagon shaped ball, as opposed to rolling a circular ball.


I beg to differ....hand cycling does help with breakin polished or not. Anyone who is skeptical can try it themselves.

most people over polish and most surfaces they polish are not necessary.

The recontouring is more important than the polishing. There are thousands of these weapons used by the military without any polishing.

I'm not saying not to polish, I also polish but proper recontouring will give you the biggest performance gain.

The polishing is what helps the closed bolt load, as it slips easier. You're always gonna have to push a little, even if you take so much off that you ruin the bolt.
If you propperly polish the right places, it creates a smoother action & trigger pull. One can not argue otherwise.
If one were to sand down the bolt & leave it rough, there would be a rather large power loss.
As for all the military S-12s having nothing at all done... Well... I would assume they don't shoot cheap-ass bird shot too much in the Russian military.

My gun with 3 .09375 ports & a SLIGHTLY profiled highly polished bolt runs winchester (the lousiest I can find) birdshot like a raped ape & rarely EVER chokes... Even when I shoot it one handed.
It cycles the same shitty load reliably with the drum set to the correct (higher) spring pressure as one would have the drum set for high brass.
The gun with 3 ports @ 3/32 (.09375) is only warranted to shoot federal ammo, & on many guns, they won't properly cycle federal ammo without lightening the drum's spring pressure.
My end result is a gun that shoots with the utmost reliability, but will not cycle weak loads on setting 1, thus proving proper gas pressures.
I can't argue with perfection.

As for unnecessary areas, yeah,,, the whole carrier doesn't need to be a mirror & the top of the bolt that has no friction points are unneeded for performance.

I "advise to" tune every gun I "advise on"the same as mine & am experiencing the same results as mine.





Does anyone have a side by side pic of an untouched factory bolt vs. a re-profiled bolt. I want to re-work my bolt for closed bolt mag insertions, but I don't know how much to take it down... Thanks in advance.



This picture would be worth 10000000000000000 words!! Please!

Diego

Scroll up.
There's a whole rippin' dick-load of pictures of bolts.
Take a picture of your bolt for a factory pic.
Next time I tune a gun, I'll try to take a pic before hand.



Straight from IZHMASH website:

"The magazine can be charged with any twelve gauge ammunition - even 70, 73 and 76 mm long at the same time. The shotgun can fire both standard and non-lethal ammunition."

So does that mean that out of the box all your guns have been able to cycle light bean-bag loads?

I'll have to try some less lethal again. :unsure:
It costs an arm and a leg, but since that says that, I'd like to test that theroy. Back when my ports were undersized it sure choked on it.

I'm assumig that really is from the Izhmash website, because it sounds familiar.

But Tom Cole, our RAA warranty repair center guy, only warrants them to run shells as weak as federal bulk pack... The rest is up to us.
I wonder if KVAR will set up a competing warranty center & warranty less lethal round reliability? That would be cool.

Maybe our LEOs here should pull that up & make Tom make their guns run bean-bags reliably for free?

Edited by Paulyski, 30 September 2010 - 10:33 PM.

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#80 saiga tech

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Posted 01 October 2010 - 07:39 AM






Can just pulling the charging handle over and over polish everything where it needs to be polished? It is is already mirror-like on the edges that contact.

What Cobra said is correct.

It's not just about polishing, it's the re-profile too.
Knocking down the excess angles edges that move against the rounds reduces force needed to cycle the gun.
Kinda like if you were to try to roll a hexagon shaped ball, as opposed to rolling a circular ball.


I beg to differ....hand cycling does help with breakin polished or not. Anyone who is skeptical can try it themselves.

most people over polish and most surfaces they polish are not necessary.

The recontouring is more important than the polishing. There are thousands of these weapons used by the military without any polishing.

I'm not saying not to polish, I also polish but proper recontouring will give you the biggest performance gain.

The polishing is what helps the closed bolt load, as it slips easier. You're always gonna have to push a little, even if you take so much off that you ruin the bolt.
If you propperly polish the right places, it creates a smoother action & trigger pull. One can not argue otherwise.
If one were to sand down the bolt & leave it rough, there would be a rather large power loss.
As for all the military S-12s having nothing at all done... Well... I would assume they don't shoot cheap-ass bird shot too much in the Russian military.

My gun with 3 .09375 ports & a SLIGHTLY profiled highly polished bolt runs winchester (the lousiest I can find) birdshot like a raped ape & rarely EVER chokes... Even when I shoot it one handed.
It cycles the same shitty load reliably with the drum set to the correct (higher) spring pressure as one would have the drum set for high brass.
The gun with 3 ports @ 3/32 (.09375) is only warranted to shoot federal ammo, & on many guns, they won't properly cycle federal ammo without lightening the drum's spring pressure.
My end result is a gun that shoots with the utmost reliability, but will not cycle weak loads on setting 1, thus proving proper gas pressures.
I can't argue with perfection.

As for unnecessary areas, yeah,,, the whole carrier doesn't need to be a mirror & the top of the bolt that has no friction points are unneeded for performance.

I "advise to" tune every gun I "advise on"the same as mine & am experiencing the same results as mine.





Does anyone have a side by side pic of an untouched factory bolt vs. a re-profiled bolt. I want to re-work my bolt for closed bolt mag insertions, but I don't know how much to take it down... Thanks in advance.



This picture would be worth 10000000000000000 words!! Please!

Diego

Scroll up.
There's a whole rippin' dick-load of pictures of bolts.
Take a picture of your bolt for a factory pic.
Next time I tune a gun, I'll try to take a pic before hand.



Straight from IZHMASH website:

"The magazine can be charged with any twelve gauge ammunition - even 70, 73 and 76 mm long at the same time. The shotgun can fire both standard and non-lethal ammunition."

So does that mean that out of the box all your guns have been able to cycle light bean-bag loads?

I'll have to try some less lethal again. :unsure:
It costs an arm and a leg, but since that says that, I'd like to test that theroy. Back when my ports were undersized it sure choked on it.

I'm assumig that really is from the Izhmash website, because it sounds familiar.

But Tom Cole, our RAA warranty repair center guy, only warrants them to run shells as weak as federal bulk pack... The rest is up to us.
I wonder if KVAR will set up a competing warranty center & warranty less lethal round reliability? That would be cool.

Maybe our LEOs here should pull that up & make Tom make their guns run bean-bags reliably for free?


here's the link military s12

Again I say there are thousands of these weapons being fielded in the russian military without polishing

I understand what you are saying also....the domestically available s12's need work just don't need to polish it like a mirror

Proper profiling is more important

Let's just call it a day and be friends :)
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#81 RLTW

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Posted 04 October 2010 - 01:16 AM

Great Advice from all.... I just did my S-12 this weekend, 223 and Draco.. Got going and couldn't stop... I didn't remove any metal off the bolts, just polish. I'll see how the S-12 fires then maybe do more on the bolt.

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#82 sasquatchvnv

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Posted 15 October 2010 - 02:50 PM


Guys, What is this "Red Compound"? I was just at Walmart and then went to a automotive store, but couldn't find anything except the Mcguire stuff made for removing scratch and polishing rims.


I think they might be referring to the small pack of red polishing compound that comes with most Dremel kits. My local Home Depot sells it stand-alone on the end cap with all the other Dremel accesories. I used it on mine and the results were very good. Not the caliber of Paul or Cobra's work, but pretty darned smooth and it cycles everything I've tried so far, including Wally World bulk.



Its official title is "jewelers rouge" You should be able to get it any machine supply.

#83 protean

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Posted 16 October 2010 - 04:41 PM

Just wanted to thank Cobra for doing my bolt and FCG. After reading the posts I finally decided to have the bolt polished but lack the necessary tools and skill. Cobra took care of everything at a great price. He was also able to finish everything in a few days. Actually he finished it too fast as I'm having my Saiga gun koted and it's not done yet so I have to wait to put it back together. The anticipation is killing me...Thanks Cobra!!

#84 Cobra's Custom LLC

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Posted 04 November 2010 - 11:21 AM

You're most welcome protean. Glad to be of help. I have posted pics and info in this thread in an attempt to clear up questions that have been asked here and in other threads....and try to warn them about how easy it is to mess it up if you don't watch out. Not everyone has the means to fix a big mistake. Some don't have the tools required or even want to mess around if they can just send it somewhere and get it done very well. I'll always be available to help these folks and have had nothing but very good feedback so far. I went ahead and started a web page [ link in sig below ] to make it easier for people to see what they look like before and after, and just what advantages there are to getting it done right. There's button there to another page with feedback from people who have sent me theirs. The bolt itself is not the only thing that gets a lot of attention here. I reprofile and polish the carrier too, and polish all surfaces on it that interact with other parts, even the spring guide channel, bolt lug channel, and inside the rail guide slots. When the hammer, rails, and other mating surfaces are all polished too, it makes a hell of a difference in how smooth everything operates. I also work on the extractor and when I'm done with it and the extractor notch, the bolt can close that last half an inch or so without as much resistance. With a normal factory recoil spring it can close under it's own power if ridden home, not that riding the bolt home is a good thing, just stating a point about the lessened resistance. If it opens and closes easier it will cycle better with light loads.
To the DIYers, there is lots of info posted on this forum and I still don't mind answering questions. I have always done that here and have posted numerous tutorials in an effort to help others like myself who enjoy trying and doing things themselves.

On the closed bolt loading of mags...literally all I have to do with mine is hook the front lug and hold it in place there while rocking the mag back into position. As long as you hold the front lug in, pushing forward at the top while rocking the mag in, it's quite easy, even with all my drums, as long as they are downloaded by one shell. Stick mags though, if loaded to their intended capacity, rock in just fine against the closed bolt. Without the mods to the bolt it's much more difficult. The top round runs into the shoulder of the bolt and dislodges the front lug unless you work really hard at it or push up into the well, then forward while rocking back...a PITA.

Lastly...the top round in the mag does not get squashed out of shape as bad after the mods, if you want to leave the gun loaded with the bolt closed. I've loaded mine and left it for a week to test this. It was with an SGM 12 rd mag. I also had an AGP with 10 rds in my other gun to test it too. Both cycled the first round and didn't jam.

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#85 Bitbasher

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Posted 09 November 2010 - 03:49 PM

I will also chime in here, I had a gun that would not cycle light rounds, but after Cobra did my bolt and hammer my gun will now cycle Walmart bulk pack ammo, both Winchester Universal and Federal Multi-Purpose. It's a substantial difference in reliability and I do not regret getting it done for a second.

Also, He did a trigger job on mine and the trigger feels noticeably better, its a significantly lighter and smoother trigger that has made the gun more enjoyable to shoot. It's obvious enough that my friends that shot the gun before and after asked if I had changed the trigger without me mentioning it to them.

I will also concur, it is now much easier to load magazines on a closed bolt. I can do so pretty easily now with my AGP 8 and factory 5 rounders.

Edited by Bitbasher, 09 November 2010 - 03:50 PM.


#86 JTE

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Posted 09 November 2010 - 04:47 PM

Just a word of caution.

I enjoy reading all the post about polishing the bolt, carrier, hammer, etc. It is fun to do and it gives a feeling of accomplishment. But here is the problem which hasn't been addressed, mainly because very few people really know how to build/tune one of these actions properly or understand the relationship/interface of the parts during the cycling of the weapon system.

I will take pictures when I get the chance, but here is a snapshot overview:

There is a TIMING relationship between the Bolt Lugs, the barrel hood, the lug recesses and the carrier. As the bolt moves forward into battery the top lug will contact the bump area of the barrel hood which will initiate the bolt roll over (lugs into lug recesses) into battery, and then the carrier moving forward will complete the roll over into complete battery/lock. Similar during unlock, there is a slight delay as the carrier moves to the rear, but this time the carrier lug recess will contact the lug and unlock the bolt.

When you start polishing areas of the bolt, barrel, etc. you can take off enough materiel to destroy the proper timing relationship between these parts. You may never know the difference until you have cycled a properly timed weapon.

When the bolt roll over timing is correct, the bolt will close like it is on ball bearings. If I tune a Saiga 12 action, you can hold the bolt 1/2 inch from battery, let it go and it will close all the way into battery with an extra lite recoil spring in the gun. This includes properly profiling the extractor and a JT Engineering extractor spring.

All these parts work together and removing as little as .003 can alter the timing of the system. Sometimes I have to TIG weld the bump area of the barrel hood to achieve the proper timing sequence.

When the system is out of time you will start to wear off the corners of the lugs and the lug recess. Yeah, it will still work and you will not know the difference unless you have tried a gun that is properly timed.

Gotta go finish sighting in the guns for Area 6 Championship, but I will elaborate further when I get the time.

Regards,

Jack Travers
JT Engineering
www.jtengineering.org
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#87 post-apocalyptic

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Posted 10 November 2010 - 09:13 PM

Here's my gun:



Bolt/bolt carrier/fcg polishing and tuning performed by Mike at Lone Star Arms. :smoke:
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#88 PJJ

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Posted 08 December 2010 - 04:30 PM

Most Esteemed Sirs;

I have my bolt profiled and polished in accord with your several instructions and photos....but still have a question.

In one of Cobra's photos, I see the longish flat on the bottom of the bolt carrier seems to have the ramps blended into the flat more so than original. Is this so? And if so, is there any appreciable amount of material moved from the flat itself, beyond that taken to do the blending?

I've long been a polishing fool, and brass, silver, chrome, stainless steel, iron (even 150 year old pig iron from old blast furnaces), in short, anything onto which one can apply polishing wheels and compound (my receiver cover looks very cool and shiny, since it beckoned way too strongly for my polishing touches) is grist for my mill.

Thank you....I am and remain sincerely yours,

Parson Julabee Jones

#89 MIAMI VYSE

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Posted 08 December 2010 - 11:00 PM

damn thanks for all the info guys......if you guys all keep it up we all just might become semi pros :super:

Edited by MIAMI VYSE, 08 December 2010 - 11:11 PM.

if it doesn't fit force it, if it breaks then it needed to be replaced anyway!

#90 S-12 Pauly

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Posted 09 December 2010 - 11:18 PM

Most Esteemed Sirs;

I have my bolt profiled and polished in accord with your several instructions and photos....but still have a question.

In one of Cobra's photos, I see the longish flat on the bottom of the bolt carrier seems to have the ramps blended into the flat more so than original. Is this so? And if so, is there any appreciable amount of material moved from the flat itself, beyond that taken to do the blending? Answer - NO.

I've long been a polishing fool, and brass, silver, chrome, stainless steel, iron (even 150 year old pig iron from old blast furnaces), in short, anything onto which one can apply polishing wheels and compound (my receiver cover looks very cool and shiny, since it beckoned way too strongly for my polishing touches) is grist for my mill.

Thank you....I am and remain sincerely yours,

Parson Julabee Jones

Just smoothen the transition!

The "flat" on the bottom of the carrier pushes your hammer into the disconnecter. If you remove much material from there, you can screw stuff up.
(& actually set up a rare slam fire risk)

I have repaired (added steel) other members carriers to fix this mess up.
So, de-horn the ends, but keep the thickness along the center where it travels down the hammer unless you know exactly what you're doing with regards to the hammer entering the disconnecter.

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