Hi, new here. I have a fightlite scr with a 5.56 upper and it shoots just fine. I tried my hand at building a 300 blk upper for it with a DSI 16 inch barrel, aero precision upper, some standard gas block, and a carbine length gas tube. I'm having an issue with it cycling now. It will shoot and eject the brass most of the time, however it will not chamber the next round. I'm taking it as a gassing issue. Has anyone ever run into an issue with the SCR like this, or see any flaws and have suggestions for the gas system? Thanks in advance.
Fightlite SCR cycling issues
- Thread starter Domant222
- Start date
BDinPutnam
.475 A&M Magnum
Do you have an adjustable gas block?
Oh, and welcome aboard.
Oh, and welcome aboard.
Thanks, and no I don't have an adjustable gas block on it, the barrel and gas block have .750 ports though. I've read that sometimes folks have to drill out their barrel port more but I would prefer not to. I should mention I've tried both supersonic and subsonic ammo. I think that the system is just on the low side because once or twice it has cycled fully with the supersonic.
I have no experience with the SCR but it sure sounds like you may have a gas issue. Drilling the gas port may be your only option as there’s no AR15 style buffer. I don’t believe you have the ability to tune the recoil end of the equation but I’ll defer to folks with hands on.
I have 3 SCRs, the only way to tune the recoil system is through the gas flow. Does your 300 Blackout have a carbine gas system or pistol gas system? Most 300BOs run better with the pistol gas system. You are most likely going to have to open the port up quite a bit to get it to function properly.
I only run supersonic ammo through my blackouts, all of mine run pistol gas systems and seekins low profile adjustable gas blocks.
@dsdmmat, it has a carbine system. Unfortunately I didn’t know it would be a problem, plus finding a non threaded barrel was pain enough. Probably should have done more research as now I see that DSI also has a pistol gas barrel. Would an adjustable gas block alone do the trick? Or am I takin this sucker to a gunsmith to have done right?
No you are already running it wide open you will have to drill the gas port.
My $0.02 - don’t let drilling the gas port discourage you. Just go slow and open it a little bit at a time and test. If you end up overgassed you can slap an adjustable gas block on it. As it is the rifle is not usable for anything other than plinking.
technicalgadget
.223 Rem
Ensure 100% positive alignment of the barrel gas port and the gas block. I have seen plenty of misaligned ports which have contributed to poor cycling.
I took apart my upper and came to a realization. Where my gas tube butts into my gas block, the hole in the tube isn’t correctly lined up with the hole in the block causing the wall of the tube to somewhat hang in the way of the block hole. Only issue is that it’s pinned in the right spot, so they just don’t match up. You can tell as the end of the gas tube isn’t flush with the end of the channel of the gas block. Should I have bought the same brand for each to ensure they’d match up?
pictures would help but if you are talking about the end of the gas tube not lining up with the end of the gas block that is not an issue. You have to look inside the gas block to see that the ports are lined up. Another test would simply be to blow into the tube and feel if the air is coming out of the hole in the gas block. Look inside the gas block you should see the hole in the tube if it is alligned correctly.
I had a similar issue with my .458 upper's gas block. I just used a drill and appropriate sized bit at a very slow speed to make hole.
Refer to pictures SOLVED: .458 SOCOM upper not cycling
Refer to pictures SOLVED: .458 SOCOM upper not cycling