The build is now 100% done, hopefully at least for a while. After a bunch of research, I ended up selecting a lower parts kit from G&R Tactical. I chose the option with the Magpul trigger guard an no trigger, hammer, and disconnector. The kit went in with no issues, and I ended up putting a Bill Springfield modded trigger group into it.
The Mega lower has a polymer tipped screw that presses against the upper to eliminate all movement between the two. It took a few minutes to get the pressure correct....too much and the rear pin won't move without a bullet or punch, and too little and there's noticeable wobble. I've got it set for zero play and moving the rear pin only requires a little extra pressure.
I've put 75 rounds through it so far, with the remaining 25 break in rounds to go down the tube tomorrow.
I loaded up 25 rounds with 115 grain SMKs over Reloder 10x tonight, which I'll try out in two or three weeks.
I bought a couple PRI 15 round magazines to try out for load evaluation sessions from the bench. I've never used a PRI mag before, but these will likely not be the last ones I buy. Not only are they significantly shorter than the C-Products 25 round mags (imagine that) they are obviously built to a higher standard.
The PRIs were a little over twice as expensive as the C-Products, so the higher quality wasn't a gimme. I just grabbed a C-Products 308 mag out of my closet, and it is welded in a completely different manner than the 6.8s. The 6.8s are spot welded, and the .308s seams are butt welded together and done with adequate precision. Unfortunately, the 15 round PRIs seem to be the cheapest option, with all others running about $10 more. I may end up getting a few of those if I find them on sale, since they look and feel different from my other aluminum AR mags. This isn't a big deal, since I primarily use P-Mags for the 223 and 308.
Since pretty much the only visual difference is the lower's roll mark, I didn't take any more photos.
I'll probably post the results of the first accuracy tests, and maybe a short comparison to my 308, which is likely a better competitor to it than my cheap(ish) 223. It really needs to cool off some. I don't like working up my handloads in 90 plus degree heat, and the increased pressure and lack of barrel cooling (and sweat) the heat causes.
