jlpatterson3 0 Posted July 10, 2013 Report Share Posted July 10, 2013 Have a Saiga IZ-332 and an Arsenal AK-140US muzzle brake (Bulgarian reproduction for 7.62x39, M24x1.5). The brake does not screw all the way back to the detent pin. Isn't it supposed to ? This rifle came with what looks like a threaded Bulgarian FSB with detent pin. I just had to remove a barrel shroud to get to the threads. The brake stops right before the pin. It appears to stop when the threads end. I can easily push in the detent pin while screwing on the brake -- the brake still doesn't go any further. Tried screwing on this M24x1.5 conduit panel nut. Maybe I don't fully understand how nuts and bolts work, but I expected the panel nut to make it past the threads to the front-sight. The nut stopped in the same place. Seen quite a few forum topics that state that most muzzle devices will never screw all the way on to a Saiga, but I wasn't sure if that applies to an IZ-332. In all of those cases, the barrel had to be threaded and/or the FSB had to be added. Again, isn't that just a Bulgarian FSB ? meant for that kind of muzzle brake ? Did I damage the threads ? What is happening to keep the nut from making it all the way to the front sight ? Quote Link to post Share on other sites
PRISONSHANK 70 Posted July 10, 2013 Report Share Posted July 10, 2013 Did u have to free a weld to get the muzzle nut off? Any burrs or crossthreading u can see? The break on my sgl definitely screws down flush. Quote Link to post Share on other sites
paprotective 362 Posted July 11, 2013 Report Share Posted July 11, 2013 Take a digital caliper that has the TAIL measure on the handle and check the threading DEPTH on the brake.. may its bottoming out in the brake or the threads were not done properly inside the brake all the way forward..?? Maybe a TAP is needed on the brake.. Quote Link to post Share on other sites
thebuns1 4,323 Posted July 11, 2013 Report Share Posted July 11, 2013 It should get much closer than that. About the only time they won't is when people try to use a short collar brake on the longer current production FSB, but usually with the 74 series. Check for burs. Quote Link to post Share on other sites
mancat 2,368 Posted July 11, 2013 Report Share Posted July 11, 2013 that FSB is a short-collar FSB, but the long-collar brake should go on all the way. OTOH, the threading on your particular long-collar brake might stop before you reach the bottom of the short-collar FSB. it also looks like the threads are a little dinged up towards the rear. Quote Link to post Share on other sites
thebuns1 4,323 Posted July 12, 2013 Report Share Posted July 12, 2013 (edited) that FSB is a short-collar FSB, but the long-collar brake should go on all the way. OTOH, the threading on your particular long-collar brake might stop before you reach the bottom of the short-collar FSB. it also looks like the threads are a little dinged up towards the rear. I may be wrong, but I was under the impression that the newer production Russian FSB's were of the long collar design to accomodate the newer, long collar brakes. I was unaware that they were still using a shorter collar FSB, such as those used on the mid 80's rifles. Either way it should thread on. I have an older style Russian zig-zag brake on my SGL, and it doesnt thread completely on like the Arsenal long collar brake does the rifle came with. It lacks about 1-2mm, and thats the brake collar not letting it seat any further onto the FSB. I wouldnt imagine Izhmash would use a Bulgarian FSB on one of their rifles. Edited July 12, 2013 by Captain Hero Quote Link to post Share on other sites
mancat 2,368 Posted July 12, 2013 Report Share Posted July 12, 2013 Izhmash still uses old surplus parts on some of the Saiga sporters with a complete front end. This includes the older-style short-collar FSB. You can visually ID them without having to see the threads. The short-collar FSB has a squared lightening cut with a shallow indent below. The long-collar FSB has a rounded lightening cut with no indent. See this image: long collar on top, short on bottom. 1 Quote Link to post Share on other sites
thebuns1 4,323 Posted July 12, 2013 Report Share Posted July 12, 2013 Izhmash still uses old surplus parts on some of the Saiga sporters with a complete front end. This includes the older-style short-collar FSB. You can visually ID them without having to see the threads. The short-collar FSB has a squared lightening cut with a shallow indent below. The long-collar FSB has a rounded lightening cut with no indent. See this image: long collar on top, short on bottom. Cool. I was aware of the lightning cuts, but didnt catch those in the OP. I wonder what the chances are of me coming across one that had the threads pinned? Prolly not very good. Quote Link to post Share on other sites
jlpatterson3 0 Posted July 13, 2013 Author Report Share Posted July 13, 2013 Someone with the rifle in hand had to point this out to me, but it looks like the last thread got a little crimped towards the end. I'm sure I did that while getting off the shroud. Eventually cut the shroud in two with a Dremel and a cut off wheel which is why there a couple of nicks across the threads, but I started with a pipe cutter. Maybe the pipe cutter crushed the thread when I clamped it down. Did a full conversion of this rifle including a bullet ramp and hands down getting that shroud off was the most painful part. Now I'm thinking I need to get my hands on a die to restore that thread's width. Hopefully that will do the trick. Quote Link to post Share on other sites
vulcan16 971 Posted July 13, 2013 Report Share Posted July 13, 2013 spellbinders comedy club " post="916223" timestamp="1373755213"]Someone with the rifle in hand had to point this out to me, but it looks like the last thread got a little crimped towards the end. I'm sure I did that while getting off the shroud. Eventually cut the shroud in two with a Dremel and a cut off wheel which is why there a couple of nicks across the threads, but I started with a pipe cutter. Maybe the pipe cutter crushed the thread when I clamped it down. Did a full conversion of this rifle including a bullet ramp and hands down getting that shroud off was the most painful part. Now I'm thinking I need to get my hands on a die to restore that thread's width. Hopefully that will do the trick. Try a thread file first. You can find them at most any tool store. Quote Link to post Share on other sites
jlpatterson3 0 Posted July 28, 2013 Author Report Share Posted July 28, 2013 Just wanted to report back ... Used a thread file and then followed up with a somewhat inexpensive ($25) rethreading die. The brake screws right on like it is supposed to now. Thanks to everyone for their helpful comments. Quote Link to post Share on other sites
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