Building an M4 without NFA: Longer Barrel Carbine or Super-Size Pistol?

[Renegade04]

TBH, most of the use I get from Rear-End Furniture is as tail-weight to help improve balance, something I figured out while handling an 07/SOT friend's TSMG's. Sometimes as a carrier for spare mags, but mostly as ballast. The stubby little arms (I'm 5'6", IIRC around like a 9-10" LOP) don't help much either, LOL.

OTOH, if I stick to pin-weld or 16" w/stock, that allows flexibility so that others in the household can use it if needed rather than being as primary-user-specific as the "briefcase special" project. 6920OEM1 has a certain "keep it simple" appeal as a starting point... and since this is planned as one half a His/Hers set, it would probably be a good idea to ensure that either of use can use either iron in case one breaks while on the range.

I, too, am 5'6". I do not have any issues with any stocks, even the A2. As far as your dilemma, you may want to go ahead and get a 16" with a stock for family use. It would be much simpler. AS far as a user-friendly stock that will suit your situation, that will be trial and error for the most part. You will need something you can attach some sort of ballast for when you shoot.

[Diamondback]

I, too, am 5'6". I do not have any issues with any stocks, even the A2. As far as your dilemma, you may want to go ahead and get a 16" with a stock for family use. It would be much simpler. AS far as a user-friendly stock that will suit your situation, that will be trial and error for the most part. You will need something you can attach some sort of ballast for when you shoot.

Right now my "heavyweight" carbine uses a FAB Defense mag-carrier stock with their monopod recoil pad, based on something an old wargaming buddy who was IDF had his armorer rig for one of his guys about our size though the full-length free-float adds a ton of front weight. The briefcase rig has an SBM4 with a 40-round PMAG stuck in its tunnel as a ready reload (not live, this is an ergonomics test rig on an unmachined 80% at this point), and I bet for any build some saddlebag-style carriers with extra mags would be expedient ballast with a useful emergency role rather than just "weight for sake of weight." The other thing that doesn't help is the combo of "never lost the baby fat" and seemingly never having grown any pecs--something I admittedly need to start at least cranking out some pushups every morning and otherwise working on so that even if I'll never measure up by Will Brink standards I can at least maybe have something up my sleeve you wouldn't expect from "just another tub o' lard." If I go rifle, thinking either the basic M4 waffle with an added recoil pad or a SOPMOD, trying to match the "Marine Corps Annual Rifle Training" specified config in general look and layout--right now I'm thinking writeoff cans, go BCM pin/weld 14.5 with stretched A2 on a Colt or BCM lower and if a miracle happens I can always have the A2 cut off and replacement pinned later.

Some comparative numbers on potential users...
Me: late 30's, 5'6, 225lb.
Mom and aunt: both 60's, each 5-2 to 5-3, 320-340lb. (we're working on trying to trim mom down, get her out of the early stages of morbid obesity-induced congestive heart failure but it's a long slow process)
Girlfriend: mid 40's, 5-8 to 5-9, around 160

[Renegade04]

If you are "trying to match the "Marine Corps Annual Rifle Training" specified config in general look and layout", then I say the "go-to" stock would be the M4 waffle stock (Gen 4) and add a recoil pad. As you say, if you write off the suppressor, a 14.5" barrel with a pinned and welded extended A2 FH (I prefer the one from BCM). Windham Weaponry does offer a 14.5" M4 upper assembly with a pinned and welded extended A2 FH. It appears to come with a M16 type BCG and charging handle as well as a detachable carrying handle.

https://shop.windhamweaponry.com/col.../ur14m4-7fha4b

Midway has a recoil pad for the M4 stock.

https://www.midwayusa.com/product/10...d-rubber-black