thesniper101

The bolt pattern is a dpms style, and when I removed the extractor I saw two O-rings one on top of another. But when I removed one of the O-rings it would function fine with snap caps. I think I need to go test fire it and see if it needs to be broken in or maybe the snap caps aren't agreeing with the chamber

When I worked at a local gun shop some of my bolt guns with tight chambers didn't agree with snap caps. I haven't loaded a real round yet because I haven't had time to take it to the range, I didn't want to load a live round at home and have that stuck in the rifle.

the bolt carrier from JP part # is -JPBC-5 the spring part # is -JPSCS2-10 entering into this i already had jp parts for a few of my ar-15s and really liked their parts so i wanted my AR-10 to use their components. sorry if its a little complicated, and I dont think you're being a dick, i appreciate the thoroughness. I MIGHT have solved the issue... i tore the whole gun apart and looked over everything. all the parts worked smoothly until i took a look at the bolt, i pulled the extractor out and it had 2 crane O-rings. I read reports of that setup causing problems in some guns, so I removed one O-ring and the gun extracts smoothly and doesn't bind anymore.

I contacted JP the magpul UBR is okay to run with their 308 silent capture spring, their spring can be used in ar-15 length receiver extensions. also on their 308 rifles they run te UBR with the fmos and silent capture

hello everyone im new to the forum and also new to the 308 AR world, i just completed my first 308 rifle and needed some help. i will give a build rundown in case maybe some of the parts are incompatible. But my rifle is having the bolt stick a bit when closed on snapcaps. barrel/bolt- faxon 16" with headspaced faxon bolt Bolt carrier/spring- JP fmos carrier and JP silent capture 308 size receiver set- CMT 308 set gas tube/gas block- SLR adjustable gas block and mid length gas tube Stock- Magpul UBR handguard- SLR 13" all of my internal components are DPMS platform incase anyone is wondering so back to the sticking bolt. when operating the rifle without snapcaps it functions fine, the bolt goes in and out of the barrel extension smoothly. but when i loaded snapcaps up the bolt sticks a fair bit, I dont have to mortar the rifle but i do need to pull the charging handle fairly hard to get the round out. I have never fired the weapon and I just put it together an hour ago. could the gun just be tight from being brand new? maybe a tight chamber? should I take it to the range and attempt to shoot it and see if it just needs a break in? I have built many ar-15s but ive heard the 308 is a different animal. thanks for any and all info on the matter!