Hello. I’m working on building a spare lower. I currently have a DDM4V7 full rifle, and have a Wilson 300 BO upper on order. I have decided to build a spare lower so that I will have 2 complete rifles. I consider this a “spare” lower as when I want to switch calibers, I’m simply going to run the Wilson atop of my DD lower being that I’ve installed a new trigger, butt stock, etc…
I want the spare lower so that if/when my brother or friends go shooting with me, I can let them use the spare lower. I do want it to be of decent/good parts, so here’s what I’m working with so far.
-PSA lower
-CMMG lower parts kit on order.
-Magpul buttstock that came with my DD (as I replaced it with the UBR).
-DD stock grip.
My main question is this: I need to buy a buffer and spring for this spare. What should I consider for using this with both calibers? Anything special? I figured I’d just get another H buffer like the one in my DD and call it good. All help is appreciated. Remember, this doesn’t need to be special/top of the line. I want a quality product, but not crazy quality. I was leaning towards either a CMMG or DD part, which I know are near the upper end of the spectrum anyhow. Any other part or build suggestions that I may be over looking?
Your PSA lower will be in spec and of good quality, I’m not so sure about the LPK. I know many have had issues with CMMG LPK’s to have sub-standard often out of spec parts. YMMV
As far as the buffer weight, you will very well have to experiment with different weight buffers. There is not really a stock answer here as there are many variables. Start with and H with your preferred ammo and adjust as necessary. Good luck.
for what my opinion is worth, I’d go with a different lpk. If you can find a Spikes lpk thats the direction I’d go. Then again, when it comes to builds I am the first to admit I’m a novice. (just finished my first) But the Spikes lpk worked great for me and you said this would be a spare; so I’m comfortable offering advice on this. As far as buffer systems, check out the Vltor A5. I don’t personally run one, BUT I’ve heard nothing but great things. Anyway, I’m sure someone more knowledgable will be along soon to provide you with some real help!
Thanks thus far guys, please keep it coming! I had not heard much negative about the CMMG, but I will also fully admit that I didn’t search for it’s credibility. I know they make pretty good quality rifles, and figured their kits would match. I will look into it. This will be a spare, but if SHTF, I’d like to know that this one will also go bang every time.
I feel like buffers and springs are the thing I know the absolute least about on rifles, so I’ll have to do more homework and test. I’m hoping to find one that will accommodate both calibers that I plan on running.
I’m having a hard time understanding your post. If you are primarily running the 300 upper on your spare lower I would run an H, possibly H2. I also recommend that you just a spars buffer on hand and not worry about it.
I run a 16" PSA CHF M4 profile 300blk barrel in a Spike’s upper. The lower is also Spike’s with their enhanced LPK (I live near Hays, Ks, so JoeBob Outfitters is the LGS). I run a JP enhanced carbine buffer spring, and Spike’s ST-T2 buffer (H2 weight). Functions 100% on all supersonic factory loads I’ve tried. Remington 115gr UMC, Remington Select 125gr Seirra MatchKing, and Hornady 300 Whisper 110gr VMax.
