BioHazard

I want to put a set of iron sights on my new build but am a little confused with all the options. I have an A3 upper and I was thinking it would be best to mount the front sight on the gas block to get out the way of the scope. My problem is the railed gas block is about 3/8" lower then my rifle length 4 rail handguard. What sight combo do you recommend for this setup and still get out the way of a big optic?

Its not like I beat the crap outta it, just a little tap with a brass hammer..... you make is sound so bad! <lmao> <lmao>

I had the same problem a week ago, I managed to fix it. The bolt would fully engage without a round in the chamber but would stop a 1/4" short with one. I took the bullet out the brass broke the gun in half dropped the case in the chamber lubed the lugs and bolt up and pushed the carrier forward by hand. This is where the gun guys are gonna cringe , :-) I tapped the carrier forward with a brass hammer and it closed fully. I then had to lightly pry the carrier back open, after repeating this 20 or so times I cleaned and reoiled. I put the lower back on chambered the empty case normaly and with it 2 bumps of the forward assist it was in firing position. I repeated with a live round and it fired. I have put 40 round thru with lots of cleaning and oiling all seems to be fine. All I can figure is the parts needed a little lapping to work in. This non-typical approach worked but before you do it inspect any brass that won't chamber for an obvious mechanical interference in the chamber. . See I told everybody years ago a hammer can fix anything!!!! ;D

Well did you build it? I am about to pull the trigger on a 338 barrel and build me a new upper.. Any feedback?

I got her going, the bolt was just a little stiff rotating into the barrel extension but all is good now. I had to tap it in and out a few times then it slowly started to free up. Thanks for the advice...

Its a chromed DPMS carrier and Phosphate bolt. Another question in my long line of questions. Should the bolt travel the same distance forward with and without a shell? When its broke down and I push the bolt closed its about .125" further out then without a shell, is this normal?

The bolt seems to rotate quite easily, even if I ride the charging handle it just takes a small bump of the forward assist to send it home without a shell. It seems the issue is in the extractor mechanism, I am going to play with it a bit, I have not pulled the bolt apart something may be stiff in there.

Well I give, just walked in the backyard (yes its good to live in the boonies) and tried to chamber one, pulled the charging handle all the way back released it and it jammed before getting up to the chamber and put a nice dent in the case in the neck down. I dunno, I had high hopes for this build and I don't like to be defeated but I just may need to check out a gunsmith :'(

I have been chambering this thing for over 2 hours, everything is heavily oiled and without a shell the bolt rotates into place very smoothly. When I add the shell its real stiff still. Its appears that the ejector mechanism is where the tension is, I am going to continue to mess with it tonight but its really depressing..

I just finished my first DPMS LR 308, I was so ready to fire it off today but it will not fully chamber the round. I pulled the bolt carrier and put a shell down in the barrel and it fully seats without any resistance. I then installed the carrier/bolt with the round still in the barrel. It takes a pretty firm push on the back of the carrier to rotate and lock the bolt into the barrel. I can then pull the charging handle and extract the shell. If I take the shell out and install the lower if I pull the charging handle all the way back and release it the bolt locks perfectly, if I slowly release it the fwd assist will push the bolt home. If I once again remove the lower put a shell in the chamber and let the carrier go forward until it stops the fwd assist will not push the carrier forward at all, its like its not forward enough for the fwd assist to engage. What's going on here, I have no headspace gauge but it really does not seem to be a headspace issue. Any ideas, BTW if it matters its a DPMS A3 upper. Thanks

Thanks Jgun, that is what I was thinking just wanted to make sure! Robocop, you said the 204 would also work, I am going to research this a bit because I really want a bull .204 also but was thinking I would need to build a 15 to do this...

Hello, I am by no means new to shooting my father had a sporting goods store for 20 years but sadly he is no longer around to ask questions. I just built my first DPMS LR308, with a 18" barrel rifle length gas system. The thing that drew me to the AR platform is the ability to shoot a variety of calibers but what I was wanting to do is use my lower with a few different uppers. I am going to use the 18" 308 for brush shooting and I have another 24" bull barrel for long range reach out and touch you, and am thinking about getting a 18" 338 just for the heck of it. I have been doing some reading and from what I have gathered the bolt doesn't "HAVE" to be matched to the barrel for moderate accuracy. Does this mean I can just get 2 extra uppers, handguards, gas blocks and tubes and just swap out the bolt and carrier group between uppers? Thanks, I am sure I will have many more questions in the weeks to come.