First AR-10.. DD or Seekins?

[db2000]

seems like the Seekins SP10 rail-attachment system is similar to the Aero M5E1 enhanced? barrel nut threads into upper receiver, handguard attaches to a boss or snout forged as a part of the front-end of the upper receiver. loads imposed on the rail don't get transmitted onto the barrel nut, which is how traditional rails attach?

Correct

 

[Hog Hunters]

I own many of the AR-10s. At $2500, LMT was hard to beat at their pre-COVID pricing.

The DD is super nice, and I like mine more after owning it than I did at first. Try to find one for ~$2150, put a Geissele in it, replace the dog turd grip, and you're set.

I have seen the Wilson Combat Recon Tactical at retail locally for $2500. That's the most refined rifle here if you can find it for that price. It's also quite light for a large frame.

The SIG 716i is extremely nice at $1400, but set some additional money aside for a new trigger and the ambi charging handle. The SIG's small weakness is that it's overgassed and had the strongest recoil impulse of my 16" AR-10s, but it's not bad like a G3 or anything.

 

[rpoL98]

Probably the biggest issue with AR10 style rifles is there is no mil spec for them like the AR15. Your choice of platform may/will lock you into a parts/upgrade path.

I don't know about that. maybe 5 yrs ago, that was a very valid statement, still true that there's no MIL-spec, yeah, maybe SR-25, however the AR-10 industry seems to be coalescing about 2 de-facto formats:
- Armalite AR-10
- LR-308 DPMS-high
maybe in 5 more years, we'll see the outcome of the VHS-Betamax shootout, or maybe it'll always be Ford-Chevy, but for today, those are pretty much defacto almost-standards, pretty well supported, parts conformity.

but you still have those freak-flags, those independent outliers, that have decided to forge ahead with their own unique formats: e.g. PSA, SIG 716i, with their own insidious proprietary aspects, moreso than the afore-mentioned 2 formats.

it's still good practice to not mix-n-match upper and lower receivers, but as far as barrels, rails, rail-heights, charging handles, BCGs, it's jelled pretty much. it's like cook-book, but with many recipes. or maybe a magic book of potions, and you can't substitute eye-of-newt for toe-of-frog, otherwise your bolt will over-run your cartridge. JMHO.