So I built a new SBR, its about the 9th build I have done. I tested it with M855 and it has run flawless. I am prepping this to be my dedicated gun and plan on running it in some courses in April. In prep for this course I picked up 1k of Fiocchi 62gr to try out and probably run since I can get it reletively cheap. I also bought a Spikes T-2 buffer. The upper is a Noveske 10.5" CQB, I bought 2 of these at seperate times, one NIB and this one was never fired but had been mounted, the pin channel had a little gouge from being removed or mounted from previous owner, nothing else. I sold the other one.
Range trip 1: T-2 buffer and Fiocchi. Stovepipes, FTF, and no bolt hold open.
Range Trip 2: H-1 buffer and Fiocchi, pretty much the same results with a little better reliability as far as jams go.
Range Trip 3: carbine buffer, no jams with Fiocchi but no bolt hold open. Also tried the following ammo for bolt hold open capability:
Fiocchi 62gr: BHO failure
Fiocchi 77gr SMK: BHO failure
Wolf 75gr: BHO failure
PRVI M855: BHO success
PRVI 69gr match: BHO success
Hornady 75gr match: BHO success.
so now I am at my ends, looking towards gearing up another rifle, wondering if I should send off the upper to check allignment and/or bore out the gas port and hope it comes back in time. Then I looked at my other rifles and considered 2 things, a Young Light carrier (didnt like the idea of that for a fighting rifle), or a LMT enhanced carrier (which I think I am going to try).
What should I do, would (if it worked) swapping the carrier just be working around the problem or if it works with a different carrier then there wouldn’t really be a problem?
me too, it loves everything but what I have a lot of, and I dont want a picky rifle.
By pin channel I mean the channel drilled in the barrel to accommodate the gas block pin. I dont think it’s an alignment issue at this point. I am going to try the LMT carrier next time I am out.
something is wrong, and you should not have to, nor should you, resort to bandaid fixes like light carriers are crap… have you checked all the usual suspects? leaks at the gas block / gas tube? checked for loose carrier key? checked stripped carrier movement in the receiver? tried different magazines?
i’d pull the block off and look at the carbon ring… if the barrel port and block port are off, the little black/brown carbon ring will no fully eclipse the barrel port. i’d measure the gas port while i was at it.
no leaks at GB/tube, key is staked and snug, carrier is snug, rotated mags (GI, GI w/ MP followers, Lancer, every Gen Pmag). I checked the GB and it looks properly indexed, I might take it off and check ring and port size.
After reading the thread “Best Suppressed SBR Ever???” thread I feel a little better about the enhanced carrier for the “fix”.
do you think it’s unlocking too late or something? it sounds under-gassed to me, unless my mind isn’t tracking right. enhanced carriers bleed excess gas.
I have some Fiocchi 62gr. and it didn’t run my 12.5" gun set up with a full auto bolt carrier and H buffer. The gun runs everything else I have tried. I recently gave some Fiocchi to my buddy and it choked his LMT 12.5" piston gun which eats just about everything.
Tried LMT with no luck, took it apart, was leaking at gas tube, tried another tube with no luck. alignment looks good, going to take it and press it off and check the port size…