I don’t know much about AK’s and I was wondering about my Saiga not having the gas relief cuts in the gas block. The gas tube fits real tight and seems to almost have a seal.
I was looking at my rear trunnion and it seems like the carrier is hitting it hard enough to make the bolt stem fly back and start to make a bit of a circle on the rear trunnion. It also seems that it has enough force to make the firing pin hit and make a mark in the little notch in the trunnion.
So I was wondering if not having the little ports in the gas block might be giving the carrier a bit more push than it needs.
Also do you think the venting makes any significant difference in how much dirty gas blows down the tube, building up crud even faster than it otherwise would?
I know it’s an AK pattern gun and was meant take a beating. For all I know it’s just how these guns run. I figure it’s better to ask people who know now, rather than after my rifle has taken more wear than it needs to.
Have been looking at it for a few minutes and thinking maybe I should drill a couple holes in the gas tube just to keep some dirty gas out of the receiver?
Does the gas tube not have venting? Generally, either the tube or the block should have venting. The early AKs had it in the tube, the later AKM-pattern guns had it in the block (generally, as always with AKs, there are exceptions). Having no venting at all is overgassing the gun. The Saigas use standard-pattern gas tubes, yes? You should be able to find a vented gas tube to use as a replacement.
All the Saiga rifles I’ve seen have no ports in the gas block or tube.
That being said, it doesn’t effect the gas pressure by any real degree if at all. It’s already overgassed by default and basically all the tube does is guide the rod so it goes neatly into the block on the return stroke rather than potentially baffing the edge of it if there was too much float in it.
If you’ve no fear of the gas spraying into the open air, the gun will run quite happily without the tube present at all, or, if doing that bothers you, there’s several vids on the youtube that show AKs running in semi and full auto without the tube installed.
In regard to the ports on the block or in the tube itself, they are primarily there to help cut down on carbon fouling of the rod and piston. If the still hot gasses carrying crap are allowed to vent, then the poo won’t be as apt to cook on. Nor will it be as likely to chase all the way back into the receiver body and foul stuff in there. (or spall your face if its really bad)
You can do the ports of course, but it won’t actually do anything in regard to gas pressure. All the actual work you’ll get out of the pressure is done by the time the piston clears the block as any residual is blasted around the sides of the piston down the ribs of the tube and no longer making any thrusting force on the piston face.
Adjustable gas blocks are available if you want to tweak so that the carrier isn’t giving the rear receiver block such a workout, or you can drill the existing gas block on the front end/front sight side into the actual gas chamber of the block (do not exceed 3/32") to vent gas before it gets to shoving the piston too hard which will result in the carrier stroking to within an inch or so of the rear block (depending on how close you get to 3/32") but never actually contacting it at all.
Recoil will feel like its been halved if not moreso.
Warning: exceeding 3/32 can cause short stroke issues.
AFA swapping parts to match an actual AK:
I’d opt for a new piston rod that has the carbon groove(s) cut into it as opposed to the smooth/ungrooved one the Saiga comes with.
Mechanically they work the same, but the grooved version is much more tolerant of any carbon buildup and will go much longer without needing to be cleaned as a result, even using dirtier ammunition.
And in case there’s interest.
Note that yes, the tube is vented in the pix, but there is no difference with or without the tube holes other than the fouling as previously mentioned.
Stroke testing was done by putting white lithium grease on the upper receiver rails and holding the rifle very loosely with no support against the buttstock so that the least ‘help’ would be there, (about as ‘limp wrist’ as one could get for want of a better term) then again with things anchored down as tight as possible to see if there was a significant difference in stroke distance between the two as indicated by the grease. Roughly 1/8" difference with the slightly longer stroke coming with the firmly anchored setup as would be expected.
Its worked just fine since the block porting through many different manufactures rounds and the tube holes were done at a later date and the stroke checked again afterward with the result being no change.
First attempt to upload a photo, hope it works:confused:
EDIT:
I think it worked…you should be able to see a ring from the bolt stem, and the mark in the middle of the little notch lines up with the firing pin.
I ASSume that the notch is there so the firing pin won’t hit the rear trunnion even if the carrier hits hard? Probably totally wrong though.
I have only put around 150 rounds through the gun, less than 200.
another view…I put about 30 rounds through the gun stock(to confirm function and accuracy) and then did basic 922r conversion. After that I put about another 100 to 150 mostly to function test the gun and magazines.
Correct.
Also helps ensure the tail of the bolt doesn’t mushroom over time which can create problems with firing pin bind and/or getting the bolt out of the carrier.
So do you guys think this amount of wear is normal for less than 200 rounds, or does the carrier maybe hit harder than normal?
I would think that as the recoil spring wears in this will only make it hit even a bit harder.
Should I try “fix” it, or just shoot the piss out of it?
As to can you do something about it?
Yes, tweaking the gas pressure by venting (as above) or restricting (some aftermarket available blocks)
The little rubber insert things you can buy will soften some of the bashing, but it is still going to happen and still going to eventually cause the rivets to loosen up a bit. ie: the insert is more of a ‘delay’ rather than ‘totally prevent’ type device.
The rivets can of course be re~set, and there are jigs and such availabe to do so.
Should you do something about it?
Entirely up to you.
Its not going to kill the rifle or cause a change in performance other than reducing the bash also reduces felt recoil.
In the grander scheme of things, you might not even ever see the rivets loosen up, and certainly not for a few years and some very high round counts even if you do.
Now if you’re getting actual distortion/mushrooming of the carrier itself then you might want to consider taking some action, but if it’s just the trunion getting beat up a bit there’s no reason you can’t just leave things the way they are and simply enjoy shooting it and periodically check to see if everything is still tight.
The above is strictly my opinion on the matter.
I am not certified, classified or endorsed by anyone or any corporate entity to offer specific advisement.
Use the information as you see fit, but also know that it as your own risk.
I have decided not to do anything until I can shoot my gun alongside of my friends SAR to compare recoil. I will also put some masking tape on the rear trunnion of both guns to see how they smack the trunnion.
I think I will eventually cut the gas checks in the gas block to bleed off some dirty gas.
After reading up a bit on this it seems like there are a several different ways that people use to tune the pressure(and as a result speed of the carrier and recoil).
A. Drilling a pressure relief hole, as is pictured above.
B. Cutting a grove in the piston head lined up with the normal gas block relief holes.
C. Install adjustable aftermarket gas block.
D. I found a post on another forum that was from a Finnish guy that seemed interesting:
"People over this side of the big water have worked a lot with this. The answer is to drill a hole in the gas block perpendicular to the gas vent leading from the barrel to the piston chamber in the base of the block. Then thread the hole and put a screw in it. You have just made yourself an adjustable gas AK. Procedure is very straightforward and simple. Turning the screw closed you will stop cycling completely, fully opening the screw (not removing though) will give you the bolt movement you have now, and somewhere inbetween you will have the sweet spot where the rifle cycles reliably with minimum recoil.
Do not modify the springs, that won’t do you any good."
Option A seems easy to try, and could be repaired easy enough with a small weld if it did not work.
Option B, gas pistons are cheap I guess.
Option C, I don’t want to buy a new gas block.
Option D, seems like a neat idea. More of a chance to scrap the gas block I guess. If you found a good setting, you could put a small tack weld to hold the screw.
Are any of these options used by alot of people with good results?
Other thoughts/suggestions?
Don’t think you were being a pest, just wanted to give you the info.
If your gas block is not ported, if your gas tube isn’t ported, then it’s going to accelerate the bolt carrier and wear and tear. I’d simply get a ported gas tube and replace it, then you’d be good to go.
lol OK. I dont think it matters in terms of how much gas is needed.
I’m under the impression Fuller recommended this route just to keep crap from getting in there in.
