Medium weight stainless upper build?

[mshootnit]

If you want to play along, help us spec some parts for this upper build (AR)
We are going to be removing a barrel, forearm, barrel nut, gas tube and gas block and replacing with new stuff. Here are the priorities:
1. Extremely accurate, free float, .223
2. 18" Stainless.
3. Low pro gas block.

Please tell us what parts you recommend along with the suggested vendor. I know something of barrels but would feel at a loss to come up with the best gas block, to be sure all parts "play nice with each other"

Thanks!

 

[Skylerbone]

I probably shouldn’t respond because I honestly have zero clue, but that only sometimes stops me. If those were my goals:

1. I would buy a lapping tool, makes sense to insure consistent contact and control how much torque is required for alignment.

2. Invest in a new bolt. A good one.

3. Most likely scrap the whole idea of parts swaps and start fresh.

Sounds a bit odd for a guy who just deconstructed an upper but I’m satisfied with its accuracy and was merely looking to lighten things up with a more ergonomic rail. As often as I’ve recommended Rock River Arms I readily admit that while it has never failed, I would never recommend an upper parts swap on one after what I went through this week, and I can only think they cannot be the only ones that are unpleasant to work on. The one positive note is that I’ll finally be fully assembling an upper, though with a few used parts.

Apart from my generic 3-step outline above I would offer the following:

1. Everything Seekins I own is very nicely machined and those parts I have shopped and yet to buy were significantly lighter than most of the “good enough” stuff.

2. Hopefully your trigger is up to the task.

3. The more I read about adjustable gas blocks, the more excited I am about finally jumping aboard and buying one.

 

[burrhead]

For my extended range AR I used a DPMS Lo-Pro upper receiver with a 24" White Oak Varmint barrel. The receiver is not a mil-spec but is heavier and stiffer. The barrel came from White Oak with a fitted gas block. I used a BCM M16 BCG and a Gisela SSA trigger. It is a consistent 0.4 MOA off bags at 100 yds and will stay in the 6s at 600 off a bi-pod.

I didn't face off the trunnion but did glue in the barrel with red LockTite. With 2.5 pounds of lead in the A2 butt stock and an added cheek piece, bi-pod, 6-24X50 FFP Vortex, all up it weighs right at 15#. I'm loading Hornady 75s with a bunch of Varget. I've also got a stupid amount of money in it.

Good luck

 

[Chuck R.]

I'd also look hard a White Oak:

https://www.whiteoakarmament.com/spr-barrels-mid-rifle-gas-7-8-twist-fluted.html

Fluted to shave some weight. Because I'm spending your money, I'd add an SLR AGB in Titanium (Just kidding, I already have 2, it's my favorite AGB). I too would lap the receiver face. I really like Geissele SSA-Es and have 3 of them. I'd also get the longest FF forearm possible as I like the bipod mounted "out there".