Mrj209

Hey everyone, just wanted to give you an update. Resized the gas port to 0.09375 from 0.086 and boy howdy did that do the trick. Had to close off the gas port a bit to get it tuned in but it's running like a silver bullet train now. Thanks for your help, even though the first thing I tried didn't do it, the very first post anyone ever have me advice in mentioned the gas port. You're all awesome, and thanks again!

@DNP I love how Kentucky Ballistics' catastrophic malfunction with the Serbu 50 has created a fun catch phrase

I have a #42 bit on hand. Unfortunately I need a replacement part for my gas block as i had it so completely open I blew the screw down range. It'll be a few days before I can check to see if this does the trick. Thanks for the info @98Z5V

@98Z5V I read your thread about ar308 building and I was thinking the same thing. Unless it's something very small and out of spec, that seems like a likely candidate. Can I open up the port with a hand drill and a rod in the barrel to protect the rifling? Or do I need a drill press or other tools?

Hey so I'm on my first 308 build. It's a live free armory upper and lower, 20 inch ballistic advantage barrel. With a rifle length gas system. KAK carbine buffer system. 5.4 oz buffer that is 2.5 in long. Internal buffer tube length is right at 7in. SPRINGCO carbine Spring is 11in long and has 27 coils. Rifle length gas tube is 15 and 1/8th in long. Gas port is .086in and the shoulder is .750. Odin works adjustable gas block. Bolt won't lock back on last round or pick up new round.

The heavy buffer and springco orange spring didn't help. Still won't lock back.

@98Z5V thank you for that link, that was some good reading. Lots of stuff is starting to make sense now. I have a new recoil system on the way, hopefully it's up to snuff. If I wanted to increase my gas port dia, what tools would I need? Not just a hand drill I assume...

@RacerX You choose your barrel and that determines your had tube length. Then you devine what kind of stock you want and that determines whether you're going to use rifle or carbine components. You can mix and match carbine and mid length gas systems with rifle buffer systems and vice versa.

@shooterrex I ordered the kak buffer in this picture along with the kak heavy spring. I'm also going to order the springco orange spring. Thank you for your advice.

@DNP unfortunately Armalite is sold out and I can't find that system anywhere else. I will check out some of the other posts to see if there is anything that has a similar success rate. Thanks for your post it was descriptive and helps me move in the right direction.

@DNP what buffer/spring combo would you recommend other than the Armalite system?

@edgecrusher Sir, I already said that I mean no disrespect and am honestly trying to learn.

@DNP I ran it way wetter than I normally would have because the cerakote was making it a little gummy when I first got it. Spitting lube the whole last range session. Cerakote has worn off and the bolt moves smoothly btw. So it seems there is a consensus on me needing a heavier buffer. Planning on ordering this with the spring they sell as well, good choice?

They are out of stock, and I called. Said they might be out of stock for a while. I'm wondering if you guys could explain why a heavier buffer system would fix this. It's behaving like an undergassed gun. Never able to lock back, but a perfect 3 - 4 o'clock ejection. Why would a heavier buffer and stronger spring help that? No disrespect, just honestly trying to learn. Also, what specifically would you recommend in place of the Armalite system?

Hey guys, new to the discussion board, but have been reading posts trying to get a handle on what is going on with my new build. First 308 size build, my AR-15s run well so I though I could figure this out on my own. No luck yet. I have a live free upper and lower matched set, 20in ballistic advantage barrel with a rifle length gas system, M5 carbine buffer system and Nickel Boron BCG. Waterboarding info: Aero M5 carbine buffer system. 3.8 oz buffer that is 2.57 in long. Internal buffer tube length is right at 7in. Aero M5 carbine Spring is 11.25in long and has 26 coils. Rifle length gas tube is 15 and 1/8th in long. Gas port is .086in and the shoulder is .750. Odin works adjustable gas block. Problem: fires and ejects, but won't lock open or pick up another round. Bolt locks back manually. Tried every setting on the gas block with no success. I ran out very well oiled so there is some of that in the pictures. Please help!