Reliability deterioration after barrel chop + muzzle device to 18"

[cheeseybacon 10]

I'm kicking around the idea of having my 19" barrel chopped and welding on a muzzle device for a total overall barrel length of 18 inches. What kind of reliability reduction could I potentially be looking at? It seems like a modest reduction (approx 2-2.5 inches), but even the Tromix website cautions that guns setup in this manner may have trouble with certain low brass loads. My gun has 3 ports and no action work done yet but basically eats everything except for the mega-cheapo Wal*Mart value packs.

 

Assuming my ports are already adequately sized and I get the bolt and carrier profiled and polished, is it likely that I can maintain at least the same level of reliability that I currently have without shortening the gas system or opening the ports up?

[Cobra 76 two 2,677]

Depending on what muzzle device you weld on there, it's possible but not probable. Maybe with a brake that actually works, or an adapter that lets you use some form of full to extra full internal choke, and a quality job done on the internals, plus other mods to the rails, ejector, feed ramp, barrel hood....etc...you may be able to get it to cycle some low brass. You will probably have to at least hone out the ports and adjust them slightly. I don't recommend enlarging the existing ports, but rather adding a 4th port. Only then if it won't cycle, after first doing all the other mods I mentioned, then maybe enlarge ports starting with just one of them. The larger you make them, the more crap is going to find it's way into the gas block.

[1liter 20]

I'm not an expert, you should not have to shorten your gas system unless under a 12-14 barrel. I think if you had it taken to 16 and had the muzzle device (assuming minimum length of 2 and some change inches) of your choice attached by one of the perment means clarified by the ATF. You will probably need a 4 th port angled back.

[corbin 621]

Agreed with ^^^^

 

Adding some type of choke would help create a bit of back pressure. Back when I first got my S12, I experimented with light loads that wouldn't cycle well. As mentioned, polishing things up, adding a feed ramp bevel to barrel and having lighter springs all helped. Having the polychoke on it made it cycle stronger and eject the shells farther. That's with it on full choke.

 

However, I don't use light springs now that it's "broken in" and well polished.

[Gunfixr 76]

It'll run without any serious mods, but you may want a 4th port, depending on the size of the 3 it has now. My personal gun has the barrel ending at 18" with a flash hider that's about 3" past the bore's muzzle. It does have a modified choke tube permanently installed. It has 4 .076" or so ports, and will run anything.

[cheeseybacon 10]

OK, I didn't know what the deal was with barrel hoods and just did a search. DAMN! There are some seriously messed up Saigas-12 out there, those Russians really are drunk on the job some days!

I am glad my barrel hood is good to go and doesn't require welded-on extensions. Both 2-3/4" and 3" shells are well underneath the hood with factory and AGP mags as well as the MD-20 drum! Never had a hangup on the barrel hood, so from a length perspective, I *think* my barrel hood is good to go, but I submit a picture for approval from the experts. This is a 2-3/4" shell:

 

 

 

 

 

 

 

Uploaded with ImageShack.us

 

 

 

Yeah, I know, it needs refinished. The high-temp BBQ Kylon didn't work out so well.

[Mullet Man 2,114]

Yeah, I know, it needs refinished. The high-temp BBQ Kylon didn't work out so well.

 

 

In the AK world, its called character.

[Floyd9 30]

Yeah, I know, it needs refinished. The high-temp BBQ Kylon didn't work out so well.

 

 

In the AK world, its called character.

 

In my world, I call it rust-magnet

[garnaz 215]

I had mine cut down to 18inch overall with KA breacher break perm installed.I have a tac 47 autoplug and don't have any issues

[HB of CJ 1,263]

My SBS Saiga 12 has a 15" bbl (all NFA rules apply) and works great even with the cheapo WW bulk stuff, BUT I have the 3 puck package for different loads, plus the shotgun has the aftermarket 4 position gas regulator.

 

With the tightest gas puck and with the regulator set on "4", "Betty Bucker" (the shotgun's name!) cycles just fine with the 2.75 dram loads and places the hulls in a nice neat pile. COOL. HB of CJ (old coot)

[Alpha Kilo 42]

Yeah, I know, it needs refinished. The high-temp BBQ Kylon didn't work out so well.

 

 

In the AK world, its called character.

 

In my world, I call it rust-magnet

 

Patina maybe, but guns aren't like old toyota fenders that are gonna be structurally compromised or anything

[shades_of_grey 1,092]

The gas system won't necessarily need to be shortened, but your gas ports will need to increase in number.

 

I've got a gun set-up the way you describe; ~13" native barrel, Monster Brake threaded on and silver soldered in place for oal of ~18.2", and she runs everything down to Win Universal garbage without a hiccup with a standard length gas system.

 

Mine:

 

 

Lone Star Arms excels at this kind of work.