2AUSA

thanks for the replies, everybody. I will probably order the armalite tube, just to have it. I was so frustrated with this build and this site got it just perfect. it's smooth and a lot of fun to shoot.

update: I installed the quarter in the buffer tube, took it back out with a friend to shoot and it looks like it's ejecting right at the 3:30 mark. should I consider this one finished? I may order a proper sized buffer tube. who would you guys recommend going with for a new tube?

I also went ahead and ordered a full mass bolt from jp. I didn't install it in the gun, I did the work with the low mass. but having an extra m5 lower lying around, I am glad I have an extra carrier. I may still install the heavy one, though. the rifle is heavy anyway, this criterion hybrid barrel is a freaking crow bar. ps, I forgot to install the quarter in the buffer tube. should I try that? i don't want the bcg slamming into the ears of the rifle.

well, im back in the land of the living. work got hectic, but today I finally had a chance to do some work. so I broke down the lr 308, opened the gas port up on the drill press and went out to shoot.. it looks like 98Z5V's recommendation of opening up the gas port diameter was right on the money. the bolt finally locks back after the last round is fired. I tuned the gas block and it is now kicking the brass out, instead of dropping them out at my feet. from what I could tell, it was ejecting at the 3:00 position but I will have a friend shoot it so I can watch and make sure. I thought one round may have kicked out at the 2:00 position (I wasn't paying attention) and that caught my eye, but the rest seemed to go straight out at 3:00. I have a sprinco orange spring and a kak 5.3oz buffer.

hey guys, I haven't forgot about the forums here just been really busy at work. I'm going to try and drill the barrel out this weekend. in the meantime I ordered a full mass operating system from JP and it came in the mail today.

thank you, 98Z! I will get the drill bit this afternoon and install george in the buffer tube. I'll report back with the results.

appreciate the advice, guys. I followed the instructions, as best as I could and made a post in the 308 builds section of the technical list. thanks for the warm welcomes, everybody. these forums seem like a great resource of knowledge.

hey everybody. my 308 is not locking back on an empty magazine, and the ejection is kind of weird, around the 5:00 area. shooting federal 7.62x51 BPXM80CBL 150 grain fmj. At first, I thought it was short stroking but I think the bolt may be outrunning the magazine follower. I screwed up and ordered the wrong bolt (low mass), while I was sick, quarantined with covid. shocked when I opened the package and realized the mistake, I decided to try and make it work instead of waiting months, or who knows how long, to exchange it and get the right bolt. Here is my setup, following the waterboarding post. I have a criterion 18" barrel with a JP low mass operating system and headspaced bolt. running a milspec carbine length buffer tube Buffer tube internal depth is 7 1/16" KAK heavy buffer 5.3 oz & 2.5" length blitzkrieg components sprinco ar 10 carbine buffer spring orange rifle length gas system gas journal Dia 19.02 mm gas port Dia 1.95mm I'm not sure if it's my buffer system, short stroking, hammer wedging, gas port undersized or what exactly is going on. it's not cycling properly. I've tried several fixes, including a different bolt catch, gas blocks, gas tubes, different springs and different buffer (Aero m5) but nothing has fixed the issue. something is out of spec. at this point, I'm throwing money at it and getting the same results.

thanks for the reply,98z. I actually did a good bit of research, before ordering the parts and I wanted the full mass carrier from jp. but I ordered it while I was at home from work and sick with covid and I accidentally selected the wrong bolt. my heart sank, when I opened the package and saw it was the lightweight carrier. I thought about sending it back, but with everything going on, it likely would have been months before I got the full mass. I'll read over the links you posted when I get off and send the information over. should I make a new topic, or reply in this one?

hey everybody. new guy here, from Mississippi. I've been tinkering and building ar 15s/M4s for several years now and I decided to build big brother, the 308 ar. what a challenge this first build has been. unfortunately, it's not functioning properly, so I came here for some help and knowledge. I'll try to get a write up about my rig sometime soon. it's an Aero upper and lower, criterion 18" barrel and a jp low mass carrier with a headspaced bolt.