Cracked weld new Vepr-12

[jabara572 3]

Yeh, good luck with that. lol

 

 When you clearly don't understand what you're looking at I would expect that response

 

 

Right! I know you do    

[gozuki 3]

When he's not on Facebook, Rockmup is also an 07 SOT. He manufactures guns for a living.

 

That "crack" was weld cooling, and as such would be contained to the weld itself.

[jabara572 3]

When he's not on Facebook, Rockmup is also an 07 SOT. He manufactures guns for a living.

 

That "crack" was weld cooling, and as such would be contained to the weld itself.

 

A) you're wrong- you can see in my last photo that it was cracked deep into the sight base.  Not sure how many times I can say that if people don't want to read it.  Others can keep claiming it would have stayed in the weld but, you're completely wrong since it already propagated into the base metal

 

And when i'm not here, I'm inspecting welds for a living and dealing with cracks in industrial settings ...  So.................  there's that. 

 

I really don't care if anyone is dumb enough to shoot a cracked gun, it's your own face..... knock yourself out.  But telling others to do it is liable to get someone killed.  Go ask remington/ruger/sig/glock/S&W/etc/etc. if its ok to shoot a cracked gun..... tell me what they say.

[gozuki 3]

What does any of this have to do with your fear of the crack (in the weld or even the sight base) somehow travelling to the trunnion? (where it would then somehow propagate into the chamber?)

Edited May 22, 2014 by gozuki

[jabara572 3]

What does any of this have to do with your fear of the crack (in the weld or even the sight base) somehow travelling to the trunnion? (where it would then somehow propagate into the chamber?)

 

 

Cracks in the toe and one side only almost never cross over the weld into the other base metal, at least I rarely if ever see it.  So I doubt my crack would have traveled into the trunnion, but it would eventually have cracked all the way through my rear sight base and probably cracked the sight off the gun at some later date, taking the rail and cover with it.

 

I don't think anyone should be giving out advice to shoot guns with cracks ANYWHERE on them and I would expect much better from anyone who is manufacturing guns.  As proven by mine, even a tiny crack that looks like its in the weld can easily be much deeper.  Anyway, I am done discussing the merits of shooting cracked gun, I've said my piece, to each his own on that subject.... cheers

[Sdustin 578]

I don't think even if one side had completely cracked the rear sight would fall off the gun. This isn't an ar15 were talking about.

[rockmup 12]

 Your post is a perfect example of why people should take the things they read about guns on the internet with a grain of salt and consider the source.

 

 You're dramatic to say the least. You have it in your head that there is a major issue with your gun, you sound just like chicken little. the first post tells it all.  You have no desire for it to be anything other than a major issue.

 

none of you're predictions are true but its your bubble, enjoy it.

[Eric Pate 478]

Massive overreaction. Fix it? Sure. Catastrophic failure? That's just silly.

 

But anyway, sounds like you've got it taken care of. Best of luck.

[jabara572 3]

If you dont think its a big deal, whoopty -F'ing doo.  It's still BULLSH** that a brand new $900 gun cracked after 10rds, I don't care if its structural or not.  If anyone lives in Georgia let me know,  I'll crack your sight base welds for free and give it back to you since its no big deal.  Seriously, put your money where your mouth is and I'll crack yours since you're telling me its no big deal and "just shoot it".  PM me and we'll work it out.

 

 

I'll be waiting for any takers on that.  My sight base has already been re-welded and the guy did a great job.  Hopefully this will take care of the problem, I'll post back with some pics and if it cracks again

[rockmup 12]

If you dont think its a big deal, whoopty -F'ing doo.  It's still BULLSH** that a brand new $900 gun cracked after 10rds, I don't care if its structural or not.  If anyone lives in Georgia let me know,  I'll crack your sight base welds for free and give it back to you since its no big deal.  Seriously, put your money where your mouth is and I'll crack yours since you're telling me its no big deal and "just shoot it".  PM me and we'll work it out.

 

 

I'll be waiting for any takers on that.  My sight base has already been re-welded and the guy did a great job.  Hopefully this will take care of the problem, I'll post back with some pics and if it cracks again

 

 

 I wasn't so sure before but now i'm sure of it.  lol

[Wagnikov 186]

Well I have thought about this a bit and tell me if I'm wrong. On AK rifles when the piston leaves the gas block it hits nothing, and therefore there is no impact or any energy transferred other than into the carrier. On a sporter saiga the gas piston slides back until it hits the back of the gas block, and the carrier continues to travel, therefore all of the impact force and gas pressure is stopped by the gas block itself. On a military saiga 030 or VEPR 12 the gas piston is violently thrust rearward also accelerating the carrier, but at the end of it stroke when there is still tremendous force and pressure on the piston and it hits the upper handguard/gas tube which therefore hits the rear sight block/trunnion. All of the momentum and gas pressure creates a steel on steel impact force( the kind that breaks shit-loose aka impact gun for wheel lugs, or air chisel)this force is unique to these shotguns an probably further explains the need for hand guard retainer/rsb/front trunnion welding? So these guns may I fact be even more vunerable to the dangerous over gassing so common on with this model. Someone tell me I'm wrong?!

[gozuki 3]

What tremendous force on the piston?

[Wagnikov 186]

Ask yourself this. The piston has about 1/2" stroke. How hard would you have to smack the charging handle, only have contact for 1/2" of its travel, and sent it all the way home. Extract the round. Reset the trigger. Strip a new round. And return the bolt to battery. That's how much force it on the piston in ideal circumstances. But most of the time it's much more.

[gozuki 3]

And none of it is applied to the gasblock or rear sight block.

[Wagnikov 186]

And none of it is applied to the gasblock or rear sight block.

Are you asking or telling?

[Wagnikov 186]

I'm going to stop now and say by "piston" I'm referring to the puck. The "op rod" is connected to the carrier(normally this is the piston on a rifle). Are we talking about the same thing. From now on I will call it the puck.

I really want to know

-what you think stops the puck in any shotgun?

-do you think the gas looses it pressure before the puck reaches the end of its travel?

-at what speed do think the puck is traveling when it does stop(mass x speed)?

-what is the pressure dif between wm bulk and 3" mag slug?

-and MOST IMPORTANTLY do you think the vepr is "auto regulating" from the factory

[evlblkwpnz 3,418]

If I were worried about it, I would have simply marked it and checked it after another hard session or two to see if it grew. Personally, I would ride that until it broke, just to find the limit, and then fix it. Then again, it may have never grew at all or proved to be a legitimate issue.

Edited May 26, 2014 by evlblkwpnz

[Wagnikov 186]

If I were worried about it, I would have simply marked it and checked it after another hard session or two to see if it grew. Personally, I would ride that until it broke, just to find the limit, and then fix it. Then again, it may have never grew at all or proved to be a legitimate issue.

I think there was some pettiness on both side here. Do you see where there "rear access gas blocks" have created a need to capture the puck, thereby transmitting the elactic collision all the way back to the front trunnions? And BAMB out of nowhere "WELDS" on an ak. Anyone involved with costing knows that the addition of a weld to a part skyrockets the cost of that part. (That's why I chose a career on the receiving end of that cost! Lol) but without knowing anything about guns molot dare I say Kalashnikov. It's very clear that the izzy factory and Molot factories inspire of cost and tradition deemed this weld imperative? Why. Only ak shotgun with rifle sights? So the need for precise alignment. Only ak shotgun that the puck is retained by the handguard? "The ankle bones connected to the knee bone"

[Wagnikov 186]

If I were worried about it, I would have simply marked it and checked it after another hard session or two to see if it grew. Personally, I would ride that until it broke, just to find the limit, and then fix it. Then again, it may have never grew at all or proved to be a legitimate issue.

No edit button for me!!!! The crack PROBABLY wasn't catastrophic, but it's a brand new gun and he has a right to be disappointed. I quoted evlblowpn so he could clarify his opinion on the forces/impact traveling back directly through the gas tube, and to some extent stressing the rsb, and subsequent weld. (I know he has secret Russian Intel)

[rockmup 12]

 The OP claimed that the sky was falling because he had a cracked weld on his new gun.  While disappointing to be sure, it is not the end of the world. It was a simple crack in the middle of a weld that cracked when it cooled.  He proved it when he ground it out only to find that it got smaller as he ground and it was contained in the weld itself. A simple fix. Personally, I'd have kept shooting it and never given it another thought as it wasn't going anywhere. imop

 

 The OP chose to get butt hurt over that statement. That wasn't my intent but whatever.

 

 

The rear sight block is welded to the trunnion for convenience, an assembly issue. It was better to do that then try and pin it in place. Take your hand guards off and you can clearly see. The barrel is not very thick to begin with and the way the rear sight block sits over the barrel there is not enough room for a decent size pin. Look at the barrel pin and draw a line to the front. You'll see how it falls out.

 

 

 Nothing about the gas system impacts the rear sight block at all.  

[Wagnikov 186]

Nothing about the gas system impacts the rear sight block at all.

 

What stops the puck my friend?

If you you propose that nothing does, I would love to see a vid of the gun shot without the upper handguard. Yes I realize the hand guard guides the op rod. That puck would be a sweet projectile headed strait for you face! There must be a magical air buffer brake that decelerates the puck and dissipates the energy as heat. OR as we all know the gas tube retains the puck. Therefore stops the puck in it rearward travel. The only thing up for debate is HOW much energy is left in the puck WHEN it hits. So let's hear you detailed version.

[st381 3]

Isn't the puck stopped by the oprod when it reaches it's furthest most position in recoil preventing the puck from hitting the rear site block?

 

All recoil forces are therefor directed to the rear trunnion as the BCG reaches it's most rearward position. A simple experiment of pulling the BCG back to its furthest position and then measuring where the tip of the oprod is located would certainly clarify whether or not the puck can physically move back far enough. I would also think you would be able to hear the puck hitting the rear site block even over the report of the shotgun.

 

I guess I'm not completely convinced that this occurs because it would be such bad engineering that even a Russian in a vodka induced stupor would not do that.

[Mullet Man 2,114]

The puck basically stops when it contacts the oprod. Like a newtons cradle transferring kinetic energy.

The carrier stem contacts the RSB internally but contact is made as a guide (glancing) not in blunt force.

 

The puck itself comes nowhere near the RSB.

Edited May 26, 2014 by Mullet Man

[rockmup 12]

Nothing about the gas system impacts the rear sight block at all.

 

What stops the puck my friend?

If you you propose that nothing does, I would love to see a vid of the gun shot without the upper handguard. Yes I realize the hand guard guides the op rod. That puck would be a sweet projectile headed strait for you face! There must be a magical air buffer brake that decelerates the puck and dissipates the energy as heat. OR as we all know the gas tube retains the puck. Therefore stops the puck in it rearward travel. The only thing up for debate is HOW much energy is left in the puck WHEN it hits. So let's hear you detailed version.

 The gas tube. 

 

 The piston/ puck does not travel all the way back to the rear sight block. Look at the gas tube for cry in out loud. The puck/piston can NOT even leave the gas block.

 

Yes, I pulled a nina edit. lol

Edited May 26, 2014 by rockmup

[Wagnikov 186]

The puck stroke is roughly 1/2" the carriers stroke is roughly 5 1/2."

[rockmup 12]

The puck stroke is roughly 1/2" the carriers stroke is roughly 5 1/2."

 

 

 I have no way to measure that but safe to say the majority of the energy is in the piston and carrier.  The piston/puck is a direct drive on the op rod, as soon as its moving it has the majority of the energy tin the op rod and carrier.   Pretty sure that it is negligible at best

Edited May 26, 2014 by rockmup

[Wagnikov 186]

What you guys are saying is the puck is dead before it hits the upper hand guard/gas tube?

At what point does the puck decide to stop pushing?

Does the gas impulse not have enough left and only push the puck half way down the gas block?

Let's remember the puck is what converts the pressure Into mechanical motion. It is what collects up the psi and creates linear force with a vector. It is what drives the carrier rearward. And on this model of ak shotgun it is stopped by the gas tube. It has momentum! It has gas pressure creating a force behind it. The puck bottoms out every time. It hold full pressure until the round leaves the barrel! It is, on this model, impacting and applying force on the rsb via the gas tube. I have explained it three times. The amount of force may be under discussion, but I'm not debating what parts recieve that force.i can install a load sensor in the gas tube/upperhandguard if need be. But I'm guess the same people who don't believe/understand this still think the vepr12 has an auto regulating ability. And who am I to pop someone's bubble? If it makes you have to believe a lie and ignore the truth, I envy you! I don't have that instinctual denial, and am there for left to accept the sometimes disappointing truth.

[rockmup 12]

the puck moves the full length of its travel in the gas block BUT within that travel it has transferred its energy to the op rod/carrier and follows it because of the gas volume behind it.

 

 If not, then when you fired it you would feel the puck hammering the gas tube in your off hand or thumb depending on how you grip it. Look at the end of your gas tube. Is it beat to heck ? Mines not and I have at least 1500 rounds through it.

 

No need to get mad

[Wagnikov 186]

the puck moves the full length of its travel in the gas block BUT within that travel it has transferred its energy to the op rod/carrier and follows it because of the gas volume behind it.

 

 If not, then when you fired it you would feel the puck hammering the gas tube in your off hand or thumb depending on how you grip it. Look at the end of your gas tube. Is it beat to heck ? Mines not and I have at least 1500 rounds through it.

 

No need to get mad

Lol ok. Originally all I was getting at is there is an additional dynamic involved with the Vepr12 in that the gas puck is actually held in by the handguard so it doesn't fact contact it. We agree on that. My original question was do we need to consider those additional forces new and unique to the ak platform on the Vepr 12 into potential damage caused by over gassing. In addition to the rear trunnion, the operating rod, and the carrier. Instead of being able to ask that simple question it went into a big long on my god that doesn't even happen speech. As far as feeling the hand guard move. Mine has about .005 so I don't think that motion would be perceivable during shooting.

Also the end of the op rod isn't mushroomed all the heck either but that doesn't mean there is a tremendous amount of force on it. Good steel on a square shoulder wouldn't show much. So the question remains, and I never pretended to know, how much force is exhibited at the end of the stroke of the puck? The world may never know

Hopefully this is just a factory/manufacturing defect and doesn't show up. Time will tell

[Skoodge 22]

 

the puck moves the full length of its travel in the gas block BUT within that travel it has transferred its energy to the op rod/carrier and follows it because of the gas volume behind it.

 

 If not, then when you fired it you would feel the puck hammering the gas tube in your off hand or thumb depending on how you grip it. Look at the end of your gas tube. Is it beat to heck ? Mines not and I have at least 1500 rounds through it.

 

No need to get mad

Lol ok. Originally all I was getting at is there is an additional dynamic involved with the Vepr12 in that the gas puck is actually held in by the handguard so it doesn't fact contact it. We agree on that. My original question was do we need to consider those additional forces new and unique to the ak platform on the Vepr 12 into potential damage caused by over gassing. In addition to the rear trunnion, the operating rod, and the carrier. Instead of being able to ask that simple question it went into a big long on my god that doesn't even happen speech. As far as feeling the hand guard move. Mine has about .005 so I don't think that motion would be perceivable during shooting.

Also the end of the op rod isn't mushroomed all the heck either but that doesn't mean there is a tremendous amount of force on it. Good steel on a square shoulder wouldn't show much. So the question remains, and I never pretended to know, how much force is exhibited at the end of the stroke of the puck? The world may never know

Hopefully this is just a factory/manufacturing defect and doesn't show up. Time will tell

 

 

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