Gas block surgery

[travistp 63]

Ya but still if your hitting the dowel pin right n and u have the gun stabelized the block should have turned. Worst xase scenario is put the one dowel pin you originally got out back on for more resistance making the chances lesser that it would spin.

[Barrage 33]

Eh, I've had the night to think about it and stop being such a whiner about it. Gotta pay to play, right? I'm going to buy one of the US made barrels. Is there a consensus on a recommended manufacturer for them?

 

As for doing an SBS via Form 1, I'm a lowly Hoosier and we aren't allowed to have SBS here, or I'd have started the paperwork long ago.

[travistp 63]

There is a company that makes stainless steel barrels. You will have to drill gas ports in the new barrel. As it doesnt have any

[ResponsiveResolve 7]

Eh, I've had the night to think about it and stop being such a whiner about it. Gotta pay to play, right? I'm going to buy one of the US made barrels. Is there a consensus on a recommended manufacturer for them?

 

As for doing an SBS via Form 1, I'm a lowly Hoosier and we aren't allowed to have SBS here, or I'd have started the paperwork long ago.

Sorry to hear about your barrel.......I used a 40 lb dumbbell with the rubber coating on it (for a platform) and hammered quick and firm.

 

I have been looking into chopping and perming for my S12(I want to save my factory 24"). I found these guys....http://iccmfg.com/saiga.html

 

They have a store on ebay as well, hope it helps a bit.

 

I've been thinking of getting the 12 inch one and perm. attach a muzzle brake to bring the over-all length to 18.5". Problem is trying to find that long of a muzzle brake.

 

Goodluck with your S12.

Edited May 29, 2013 by ResponsiveResolve

[bobabuee 29]

I believe there only ones making barrels http://iccmfg.com/saiga.html at this time.

[Barrage 33]

I talked to a guy on the phone from King Armory about these barrels last night. He said they're close on them, just waiting to hear back from the machine shop on them.

[travistp 63]

 

Eh, I've had the night to think about it and stop being such a whiner about it. Gotta pay to play, right? I'm going to buy one of the US made barrels. Is there a consensus on a recommended manufacturer for them?

 

As for doing an SBS via Form 1, I'm a lowly Hoosier and we aren't allowed to have SBS here, or I'd have started the paperwork long ago.

 

Sorry to hear about your barrel.......I used a 40 lb dumbbell with the rubber coating on it (for a platform) and hammered quick and firm.

 

I have been looking into chopping and perming for my S12(I want to save my factory 24"). I found these guys....http://iccmfg.com/saiga.html

 

Tromix monster brake is like 5.8" oal. Cut the barrel to 13 and your set

 

They have a store on ebay as well, hope it helps a bit.

 

I've been thinking of getting the 12 inch one and perm. attach a muzzle brake to bring the over-all length to 18.5". Problem is trying to find that long of a muzzle brake.

 

Goodluck with your S12.

[zaxon_182 44]

Icc's barrels are 4130 chromoly, not stainless FYI.

[travistp 63]

I know they are but the ones I saw were a few months back some small outfit made a handful of them.

[burntpowder 23]

Let me ask you guys this. If you were to purchase one of these 18-inch replacement barrels, how my gas ports would you drill in it? I ask this because they have been imported with 2, 3, and 4 ports drilled in them........what would you do if you had your choice?

[travistp 63]

Whatever you want. 3 or 4 ia your best bet. I like . Could always do 5 at a smaller size. Hvae to ask one of the gurus here the correct sIe if you were to do a 5

[burntpowder 23]

I know we could do whatever we want. Looking for a guru to say X number of ports is the ideal setup for an 18-inch barrel.

 

From what is in all the previous posts everywhere they should at least be:

3 ports = .093 (3 x 0,093 = 0.279 total opening in barrel)
4 ports = .073 (4 x 0.073 = 0.292 total opening in barrel)

 

One would assume if you are doing a 5 port setup you would want to keep the total of all holes right around 0.3 ?............but then again, why would you choose 5 over 3 or 4, or 4 over 3, or 3 over 4.........you get it :-)

[travistp 63]

Well bigger the ports .. more trash that will get in. Smaller the ports less chance.. I would do 5x by .058 - .060 would give you the same as 4x.073 or somewhat close. A lot of guys here are firm believers in 4x .078 but I ran mine to .073. And it eats everything. Now if I can get the shells to stop catching on the ejector port I would be ok lol

[pedal2alloy 206]

I know we could do whatever we want. Looking for a guru to say X number of ports is the ideal setup for an 18-inch barrel.

 

From what is in all the previous posts everywhere they should at least be:

 

3 ports = .093 (3 x 0,093 = 0.279 total opening in barrel)

4 ports = .073 (4 x 0.073 = 0.292 total opening in barrel)

 

One would assume if you are doing a 5 port setup you would want to keep the total of all holes right around 0.3 ?............but then again, why would you choose 5 over 3 or 4, or 4 over 3, or 3 over 4.........you get it :-)

 

You have to calculate the area of the circle using πR² . You can't multiply the number of ports by their diameters.

 

So

3 ports of .093" totals .0203 sq. inches

4 ports of .073" totals .0167 sq. inches

 

 

Here's another guy's good explanation:

http://forum.saiga-12.com/index.php?/topic/52826-whats-your-combined-port-size/&do=findComment&comment=562431

[ResponsiveResolve 7]

1/16"=0.01534 @ 5 ports

 

5/64" = 0.01917 @ 4ports

 

3/32"=0.02071 @ 3 ports

 

lol I tried to make an excel chart.....didn't paste well....

Edited May 30, 2013 by ResponsiveResolve

[Nephilim7 107]

Read this thread:

 

http://forum.saiga-12.com/index.php?/topic/81707-gas-ports-under-sized/

 

Everything Evlblkwpnz and GunFun say is good stuff, with an edge to Evlblkwpnz. Not to say there aren't other valid suggestions here or there.

 

Just from what I've read if I were doing this, I would go with 5 ports after marking the gas block window area on the barrel. I would drill (use a liberal amount of WD-40 to lubricate the cutting process) the ports thru with no angle perpendicular to the barrel centerline using a tiny drill bit to create a pilot hole. Then I would ream them to around 0.068"- ish after angling over to about 20 degrees off the barrel. The ports should point in the direction of the shooters eyes. I would assemble and shoot and slowly step up size keeping each port the same diameter. The burs should remove themselves with a bit of shooting. Keep in mind you can bevel the part of the gas block window that touches the barrel. Leave the inside surface of the gas block alone, but flare the opening out on the bottom (barrel) side to allow for greater port area. Let me know if this needs to be explained more clearly. Beveling the barrel side of the gas block port window is far superior to the infamous "D-mod". The "D-mod" is flawed and can cause real problems.

 

I would stop drilling when it cycles about 18 out of 20 shots reliably firing from the hip with an MD-20 and "Winchester Universal" bulk birdshot from Walmart. After that, I would minimize all friction points, especially the rails, hammer and carrier. How-too's are searchable on the forums.

 

Be warned. There is a lot of bad info out there on YouTube as well as this forum. Read up and digest for a while. Discern the crap and ignore it.

 

Keep track of what you wind up doing with specs and pictures and post your results. That way others can follow in your footsteps or learn from your mistakes. Good luck and good shooting!

 

In addition, to clear some of the myths in this thread:

 

No two Saigas are the same. Generally accepted port sizes are to give you a ballpark idea. Start on the low side and work sizes up.

 

Port area is not proportional. Micro-jets such as gas porting do not perform in a linear pattern as diameter increases and should never be compared by area as if this were they were similar. Dynamic fluid flow is very complicated and should be approached by most as a careful, conservative, and slow guess and check process. You can always cut more metal. It's harder to add it back. Unless you understand the finer points of nozzles and diffusers at hypersonic flow speeds, don't mess around with the math. You will only deceive yourself. I don't know a lot, but I know enough to know I don't want to mess with the math to figure something out that is easily tested and discovered.

 

I did a quick proportional interpolation of 3 and 4 ports to 5 ports by comparing the diameters, total areas, and number of ports. This is of course a linear comparison, but it should put you on the conservative side and Give you a ballpark in which to start. My tentative value for 5 ports is 0.069" diameter. I suggest starting lower than that and working up to be safe.

 

P.S. - I am NOT the guru you are looking for. If one chimes in, listen to him. I just read a lot and have a Mechanical Engineering degree, which doesn't mean much.

 

***That was a book worth... Shouldn't I get posting credit for 5 posts or something? LOL

 

ETA: Tried to fix thread link. Stupid phone...

Edited May 30, 2013 by Nephilim7

[burntpowder 23]

This is why I was not a very good math/science student...........always looked for the easy way out and most of the time I was waaaaaaay off :-)

 

Thanks for the info gents! Good stuff!

Edited May 30, 2013 by burntpowder

[Barrage 33]

Going to take this thread back with a preliminary update.

 

I called several local gunsmiths but after hearing "what is a Saiga 12" from all of them I decided to take another route.

 

I ended up fixing the barrel myself after finding a hydraulic dent-raiser tool that I rented from 4-dproducts.com. They rent quite a few different gunsmithing tools, and I'd really recommend going to these guys if you need an expensive tool for one quick job. The dent raiser I used was close to $500 after shipping, though I rented it for a week from 4-d for around $70. The best part was it worked (when used correctly).

 

This week I'll be posting the video I took while fixing the barrel, I'm really hopeful if someone else injures their barrel in the future that it will help at least point them in the right direction.

 

What was really nice was that after I fixed it and got it back together, I was also reminded that I now have drilled ports. I took it out and ran it through the cheapest of the cheap bulk Federal and didn't have a single hang-up, which never used to happen. Special thanks to Shannon/Cobra's Customs for all his help as well.

 

-Chris

[burntpowder 23]

That's awesome! Look forward to watching your video.