Wanted to get some thoughts on having 2 uppers set up for 1 lower.
I was all set initially on building a really nice 14.5 AR-15, I went ahead and SBR Registered my Noveske Gen 2 lower, but in the last few months since I have bought the lower I have shot a few matches and now don’t want the 14.5, while I was waiting I built a very nice 16inch gun, and figured if I am going to have the stamp why not get a shorter barrel, plus I want the SBR to have a can and like shorter barreled upper with cans on them.
I want this to be a very nice Combo, that I can do just about anything with or shoot any matches or classes with.
Here is my Build Plan.
Lower
Noveske Gen 2 Lower
Magpul STR Stock
SD-3G Trigger
MOE Plus Grip
Seekins button and Paddle
JP Captured Silent Spring
Battle Arms 45 Safety
18 Upper
Noveske Gen 3 Upper
Noveske NSR 16.7
JP lightweight 18inch Barrel
JP BCG and SLR Adj Gas Block
Vortex Razor 1-6
SilencerCo Brake
I am researching Cans right now and plan to either buy the Specwar K or the Octane from Silencerco
Each upper will wear the SilencerCo Muzzle Brake.
The 18 will be for competitions and the 12.5 for fun, I doubt I will suppress the 18 that much unless I use it for hunting, the 12.5 will be shot suppressed though.
plus I really like Cmc or Giesslle triggers, short throw ambi safeties, and seekins or noveske lowers, that crap add ups. Hard to have a bunch of $600 plus lowers, not to mention if they have a stamp.
plus I feel an 18 and 12.5 is a big difference in the 2 platforms and each would be better that their intended uses.
Do you know for sure the jp buffer system will work with both uppers? Because the A5 will. With the A5 you dont have to change out springs or buffers, you can simply just swap uppers without worrying about anything granted you are running a buffer that works with both.
I’ve done the lower swap thing before and unless they’re very similar builds I think it’ll just disappoint because you’ll end up compromising somewhere.
The LMOS lower won’t be great with the SBR.
An A5 won’t be great on the LMOS upper.
If you’re set on keeping just one lower I’d recommend going A5 on the lower and adjust your gas on the 18" accordingly, but that kind of negates the purpose of the adjustable gas block and JP carrier. You can get a very smooth AR if you just go A5-rifle gas-standard carrier-brake on the 18" upper. Especially if you keep the adjustable gas block. If you have the compromise, I’d compromise with the LMOS parts.
Every time I’ve planned on running two uppers on one lower I’ve ended up with two lowers.
A complete lower or stripped lower and parts kit are cheap and readily available right now. Plus you’re going to be adding suppressors and adjustable gas blocks into the mix which will require adjusting on the buffer tube setups and frequent changes most likely. Set it and forget it with two lowers and if something were to happen to one you’ve got another ready to go. Throw my touch of OCD into the mix and I’m not liking the constant changing of uppers on an SBR’d lower or the chance of forgetting to switch out a part intended for a different upper and having the rifle fail in a critical situation. That’s just me.
With the money you’re going to spend on that list of gear I’d drop another 3-400 on a quality 2nd lower.
It is a noble effort you are embarking upon, I wish you luck. I have an AR with a SBR lower where I don’t even switch uppers, just barrel and optic (LMT MRP). Of course, I have another 5.56 AR, a .22 build, finishing up a lightweight, and 2 more lonely lowers waiting to “become.”
For a very short month or so, I had a BCM upper and a complete M&P Sport… The Sport upper was useless to me at that point. Couldn’t stand having a frankengun, so I got a BCM lower from Grant.
All is well, and I’m never going to try the upper swap thing again.
