A few build questions.

[karlglen101]

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?

[warner41]

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.

[tgizzard]

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! :D

[karlglen101]

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.

[Iraqgunz]

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.

[RIGPIG]

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.