Tack14

Thanks 98Z5V. Good to see the rifle buffer tube situation is not as complex.

Heavy Buffers AR10R-XH, that is....

I still have a couple KAK 308 uppers but my focus has shifted. At some point I will, for the benefit of the forum users, try this out and report on it. But for now I am going to focus on matched upper/lower endeavors. Now I need to arrive at a good combo of DPMS Gen 1 rifle-length buffer system parts. a specific brand/model of buffer tube to match up with a Heavy Buffers AR10 XH buffer. Studying past threads info.

lol. Well, i can tell you the the same kind and ~amount of gap between upper/lower at the back is there as I've seen before. Also, the KAK 308 front pivot pin is a bit short of fully reaching the driver's side. It's probably not enough to be a problem, somewhere under 1/8". But the KAK 308 front and rear pins seem to be a good diameter match. They sat nicely together. The tension set screw on the lower was backed out already and (with no BCG mind you) nothing held them apart (ie, no "dremelsmithing" looked to be needed). It would ~probably~ work OK but since I can get an Aero upper to match I will do that instead.

Will get an Aero upper too.

HAHAHA! Thank you Matt. Funny AND good advice. Love it! Point taken.

Have a chance to pick up an Aero M5 308 lower at a good price and was thinking about maybe putting one together with a KAK LR308 upper for a build. I am curious if anybody has ever put these particular two halves together and how well they fit. I have KAK LPK's and LR308 "conversion" parts (takedown and pivot pins, bolt catch, and extended mag release (extra threads length). I'm thinking in particular of fit of the takedown and pivot pins, whether I should expect to need a dremel tool to "make it fit" (LOL), etc. Thanks Tack14

yeah that is looking righteous! Gonna have to think about possibilities.. ;)

Anyway that is how the KAK LR-308 upper and AMT DPMS 308 (they call it an "AR-10 DPMS Gen 1") lower fit together. Another build I'm workin on with same upper and lower receivers has same gap/fit but is also as snug assembled.

whoops didnt finish first paragraph. ...until I have successfully test fired, verified gas/cycling etc. and have gas adjusted and the other basic stuff. Basic sights zeroed etc.

Thanks everyone for the replies. Really appreciate all the advice, experience and insight. I'll probably be the paranoid long tailed cat in a room full of rocking chairs n00b until I have @DustBusterlooks like we are in similar range. .100" was definitely an overestimate (didn't have a feeler gauge or other implement immediately handy) @98Z5V thanks a lot. I was thinking it might be like that. It is a fairly good fit once put together. Only sound I hear is the buffer weights and upper/lower don't seem to be moving separately from each other. Here are a few pics. They're not super great but I am a little mentally challenged this evening, just got off work. 😣 I put one of my flashy's up pointing up at an angle behind to try to get some light in the gap/crack.

Thanks. Yep, will get a couple pics. Should I open a thread just for this AR? If so, maybe I'll just hold off and post there. I am relatively familiar with AR's but no expert, that's for sure. Familiar enough that I've seen AR15's over the years that had some wobbles and or daylight between upper and lower too including factory built AR's, and know that some worry about it and some don't. Haven't tried to shoot it yet. But getting pretty close now. I tend to analyze and over-analyze, but along lines of what DNP was saying, it was the ramifications of how BCG cycles and mates with the buffer tube if it's too much play that I was concerned about. Will investigate that further too, exactly how smooth or "bindy" the travel of the BCG is. It feels pretty smooth but i have not tried to go really "ride it slowly" to see if I can feel binding, but it makes sense I should try to figure out of there is any. Overall it seems fine, seriously, the rear takedown pin doesn't wobble around in the hole or anything like that,. DNP I hear you -- I'd definitely go for some matched upper/lower sets if I could have at the time. When I started researching building 308 AR's I had some difficulty finding that many brands that make both halves, but did find a couple. Grey Ghost Precision for example. Just haven't seen them around anywhere (unobtanium) anytime/anywhere recently except for the SLR ones, which do seem pretty nice, albeit expensive - although with the kind of fit these are said to have with each other I would agree its worth paying more for. Building some 308 AR's was something I always wanted to do but, well frankly I saw that as something in jeopardy early this year with the general swing of things. I looked at what I could get my hands on, and yeah, I know that is a really bad idea sometimes. But it doesn't seem like I really did that bad. Will post a couple pics when I can get some good ones with the some good lighting etc. or wait to see whether people think I ought to open a thread for this 308 AR or not.

Hi everyone, This may not really be a good question to ask without having pics ready to show, I can get a couple. But in general terms I am wondering how concerned I should be about a gap between fit of upper and lower receiver in the rear of the action? There is a bit of daylight you can see between upper and lower. At the rear where the gap is horizontal rather than vertical (due to curvature of the shape of the upper receiver at the top back face) it is less than .100". The takedown pin goes in no problem, it's actually a little on the loose side I noticed. Not crazy loose but before I got the detents etc. in if I leaned over to the right the rear pin would drop out if they were oiled. Almost looks like something is standing the upper receiver off just a tiny bit, despite the takedown pin fitting through the takedown pin lug and holes in the lower just fine. Parts: KAK Industry LR-308 upper receiver, AMT (american made tactical) DPMS pattern lower. KAK 308 pivot and takedown pins. May just be OCD but if there is a problem I want to deal with it. These lowers don't have a gap/fit adjustment screw etc. Thanks! Tack14

KAK got their dual-ejector 308 BCG's back in stock. Dunno how well liked they are (no experience with them myself) but in case it is of interest to anyone... https://www.kakindustry.com/kak-industry-bcg-308

HSGI Taco's hold 308 sized mags fairly well, not all the sides/parts of the pouches are "stitched" but kept tight (and tension adjustable) by elastic cord. Pretty neat. They have some with flap covers too but not sure how they would do with 308. Depends what you want, I guess.