BaylorHenry 5 Posted September 13, 2010 Report Share Posted September 13, 2010 (edited) hey guys, first off, thanks for the help with the muzzle brake. I put my gas block and muzzle brake onto my barrel and pinned it in. WOW WOW WEE WOWWWWW!!! Look'n sexy! went out for a test run, problem is, the rifle is over gassing! The BCG is absolutely slamming hard onto my rear trunnion. I took a .22 casing and taped it onto my rear trunnion and completely pancaked the casing. I did the same thing in my .223 saiga and the rear trunnion barely touches the 22 casing. I've already gone ahead to order a new extra strength recoil spring from wolff. What else should i do? How the heck does changing a gas block do this to the rifle?! thanks, pics will follow soon! Henry Edited September 13, 2010 by BaylorHenry Quote Link to post Share on other sites
jamesavery22 54 Posted September 13, 2010 Report Share Posted September 13, 2010 Probably help if you had a pic of your gas block. Was the gas hole in the bulgy GB the same ID as the gas hole in the Saiga GB? Quote Link to post Share on other sites
into_the_knight 22 Posted September 14, 2010 Report Share Posted September 14, 2010 strange. I always thought that the gassing was controlled by the size of the hole bored into the barrel and not the gas block's inner diameter. It is possible the gas block you bought was used and therefore the inner diameter was corroded. 1 Quote Link to post Share on other sites
evlblkwpnz 3,418 Posted September 15, 2010 Report Share Posted September 15, 2010 (edited) strange. I always thought that the gassing was controlled by the size of the hole bored into the barrel and not the gas block's inner diameter. It is possible the gas block you bought was used and therefore the inner diameter was corroded. +1 port area is determined by the hole in the barrel, not the gas block. Nearly all AKs and AKMs hit the trunnion fairly hard. Go on youtube and look at a few slo mo vids with the dust cover off. You will see what I mean. Edited September 15, 2010 by evlblkwpnz Quote Link to post Share on other sites
BaylorHenry 5 Posted September 15, 2010 Author Report Share Posted September 15, 2010 strange. I always thought that the gassing was controlled by the size of the hole bored into the barrel and not the gas block's inner diameter. It is possible the gas block you bought was used and therefore the inner diameter was corroded. +1 port area is determined by the hole in the barrel, not the gas block. Nearly all AKs and AKMs hit the trunnion fairly hard. Go on youtube and look at a few slo mo vids with the dust cover off. You will see what I mean. well that's what I thought. I've never gotten more recoil w/o drilling out a gas port. I just drilled out an SBR saiga and switched gas blocks, so I'm not estranged to the whole gas system, just not sure why this thing is doing weird stuff perhaps my old saiga gas block was partially blocking and over-drilled hole that the bulgy had unleashed it's fury? Quote Link to post Share on other sites
BaylorHenry 5 Posted September 18, 2010 Author Report Share Posted September 18, 2010 This is just an idea... what if i drill a small hole on the side of the gas block stem as a bleed off valve? do you think that would work to bleed some of the excess gas out like the M14 or FAL? Quote Link to post Share on other sites
Rhodes1968 1,638 Posted September 18, 2010 Report Share Posted September 18, 2010 I wouldn't do anything until the spring is installed to see if further modification is required. You also might try a recoil pad but thats going to be controversial here. Quote Link to post Share on other sites
BaylorHenry 5 Posted September 22, 2010 Author Report Share Posted September 22, 2010 so, I got the wolff extra strength spring and added 20+coils from my old spring in order to compensate the over-gassed system. It feels just like a normal 103 now, but my question is.. will this slam the bolt too hard forwards towards the trunnion? Quote Link to post Share on other sites
jamesavery22 54 Posted September 22, 2010 Report Share Posted September 22, 2010 strange. I always thought that the gassing was controlled by the size of the hole bored into the barrel and not the gas block's inner diameter. It is possible the gas block you bought was used and therefore the inner diameter was corroded. +1 port area is determined by the hole in the barrel, not the gas block. Nearly all AKs and AKMs hit the trunnion fairly hard. Go on youtube and look at a few slo mo vids with the dust cover off. You will see what I mean. I'm guessing this is true 99% of the time but I do know of a 1% case. Arsenal SLR-107UR. Comes with a 16" barrel that has a gas hole for 8.27"(3mm). The gas block has a pill in the port which greatly reduces the ID(≈1mm). This gas block restricts the gas blow back so the rear trunnion & rivets aren't beat to shit when it's shot in its bastardized 16" format. When its SBR'ed and cut down to 8.27" the pill has to be drilled out. I'm sure this could have been done with any of the carbine type AKs like a slr-107cr but I've never seen it... Again take pics of the new and old gas blocks. Namely of the gas holes. Quote Link to post Share on other sites
BaylorHenry 5 Posted October 3, 2010 Author Report Share Posted October 3, 2010 Arsenal SLR-107UR. Comes with a 16" barrel that has a gas hole for 8.27"(3mm). The gas block has a pill in the port which greatly reduces the ID(≈1mm). This gas block restricts the gas blow back so the rear trunnion & rivets aren't beat to shit when it's shot in its bastardized 16" format. When its SBR'ed and cut down to 8.27" the pill has to be drilled out. I'm sure this could have been done with any of the carbine type AKs like a slr-107cr but I've never seen it... Again take pics of the new and old gas blocks. Namely of the gas holes. Does anyone have a collection of gas blocks? I have my destroyed saiga gas block(that you can still see the gas hole. I wouldn't mind donating it to someone who has a lot of gas blocks and a caliper so they can answer our question. Quote Link to post Share on other sites
BaylorHenry 5 Posted October 6, 2010 Author Report Share Posted October 6, 2010 Mad props to madmailman on militaryfirearm.com, he showed me how to cut one groove on my gas piston and now it is one of the softest shooting AKs in 762 that I've shot. The excess gas is just bled off the side of the gas piston now. I took the extra 25+ coils of spring out and the BCG is no longer body slamming my front trunnion. With the bulgy brake it's amazing how little recoil there is for a .30 cal. I tried to hit one of the blow-off holes on the gas block. Kinda wish i cut the groove on the top blow-off hole, but it doesn't seem to affect my recoil or muzzle climb. Madmailman had to use 4 grooves on his tabuk, but mine took only 1. I would suggest this method but only slowly. Even if you mess up, it's just $15 to buy a new one and a few more for a rivet... but I think this is a pretty nice method to save an over-gassed rifle. here are some pics: Quote Link to post Share on other sites
paprotective 362 Posted October 6, 2010 Report Share Posted October 6, 2010 I noticed some Saiga 762 and 545 have actual HOLES where the notches are on the GB.. (just an FYI note) Maybe drill some vent holes in the spots.. can't tell from your pic if yours is THRU or not.. that may be your piston showing.. My 7.62x39 Saiga doesn't but my 545x39 Saiga does.. Al Quote Link to post Share on other sites
BaylorHenry 5 Posted October 6, 2010 Author Report Share Posted October 6, 2010 (edited) I noticed some Saiga 762 and 545 have actual HOLES where the notches are on the GB.. (just an FYI note) Maybe drill some vent holes in the spots.. can't tell from your pic if yours is THRU or not.. that may be your piston showing.. My 7.62x39 Saiga doesn't i don't think 762 saigas do. The reason I have them is b/c i put that bulgarian military gas block on (yes they do go through) I wouldn't want to drill the gas block though, that would be so much more of a pain in the azz than switching a gas piston out... Edited October 6, 2010 by BaylorHenry Quote Link to post Share on other sites
jamesavery22 54 Posted October 6, 2010 Report Share Posted October 6, 2010 ... but I think this is a pretty nice method to save an over-gassed rifle... I wouldn't recommend cutting the gas piston to anyone who can't re-chrome it. The barrel, GB, and piston get the most crap on them and the hottest. If I were you I'd give Jim Fuller a call. Make sure you're not doing anything to sacrifice guaranteed reliability. Quote Link to post Share on other sites
imarangemaster 315 Posted October 6, 2010 Report Share Posted October 6, 2010 I read a few years ago were someone solved the over gassing problem using a Chinese gas tube with vent holes in the body. 1 Quote Link to post Share on other sites
paprotective 362 Posted October 7, 2010 Report Share Posted October 7, 2010 drilling the gas tube would be the easiest quick fix.. can always replace.. IMHO.. 1 Quote Link to post Share on other sites
BaylorHenry 5 Posted October 7, 2010 Author Report Share Posted October 7, 2010 drilling the gas tube would be the easiest quick fix.. can always replace.. IMHO.. the gas tube doesn't actually hold gas though, it just acts more as a piston guide for the piston to head back to the gas block... When I switched from the saiga non-holed gas block to the 4x hole bulgy gas block, my gas actually increased despite the holes on the side to "vent". It wasn't until i put this little cut on the side to vent it that my gas into the system decreased. Why would chrome lining matter? the gas piston isn't even chrome lined anyways and I'm not shooting corrosive ammo Quote Link to post Share on other sites
BaylorHenry 5 Posted October 7, 2010 Author Report Share Posted October 7, 2010 drilling the gas tube would be the easiest quick fix.. can always replace.. IMHO.. I say that b/c if that's true, this guy's AK would never cycle: http://www.youtube.com/watch?v=_hcuVyTcITQ Quote Link to post Share on other sites
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