Any real advantage of an A4 vs an M4?

**ABNAK** · 05-30-21, 13:53

Nostalgia aside of course. Is there any distinct upper hand a full-sized A4 might have over an M4? Velocity comes to mind, which would primarily allow a greater range for optimal terminal ballistics (of course that assumes 20" vs 14.5"; 20" vs 16" and the gap narrows significantly). The rifle length gas system is the one the Stoner system was designed around, so there's that. Accuracy, all other weapon and ammo qualities being equal, *should* be about the same. Of course the M4 wins for weight and handiness.

Opinions?

The genesis of this isn't about need. I'm AR'd out as far as that goes. I have the 20" itch scratched already too (not A4 though). Just saw a decent deal on an A4 upper assembly that, with the addition of an A2 stock/buffer/spring I could easily convert a franken-M4 I have to the full-sized configuration. Yeah, I need it like another hole in my head but you guys know the deal with this affliction.

**JediGuy** · 05-30-21, 14:04

After swinging around a 20” 308 pencil barrel, I became convinced that a pencil or tightly tapered 20” 5.56 barrel is probably a worthwhile endeavor. It wasn’t that unwieldy, even LARPing through my house.

I’m also tapped out at the moment with some “have fun” builds, but I’ll probably put together an upper along these lines eventually. Whether or not it is “worth it” over a 16” barrel, I’m not sure. I did note when NZ chose 16” as their carbine barrel length.

**okie** · 05-30-21, 14:41

I would rather have something along the lines of an A1. Those 55 grain bullets doing 3k fps absolutely shred stuff. Nice flat trajectory too.

**C-grunt** · 05-30-21, 14:51

Better reliability, lower recoil, and higher muzzle velocity.

The extra muzzle velocity is good for unknown range targets. The flatter trajectory is going to be more forgiving on range estimation errors. It's not a huge difference but it could mean the difference between putting a round through the window or into the wall below it.

**Firefly** · 05-30-21, 19:20

The carbine is a compromise of a compromise that has been shoehorned into a main role.

I have way more fun with a 20” A1 than most anything else because of my long arms.

I am mulling a dedicated rifle build as well as an A2 clone. When society stops, My Hiro Oonada gun will be a rifle length gas gun.

**ABNAK** · 05-30-21, 19:42

Originally Posted by Firefly

The carbine is a compromise of a compromise that has been shoehorned into a main role.

I have way more fun with a 20” A1 than most anything else because of my long arms.

I am mulling a dedicated rifle build as well as an A2 clone. When society stops, My Hiro Oonada gun will be a rifle length gas gun.

I'm not in the Yao Ming category like you, but I'm not exactly short either! The 20" A1 AR still feels good in the hands. Hell, it was what I cut my teeth on in 1983 when I showed up at Ft. Benning.

As an aside, ever read the book written (maybe co-authored?) by Hiro Oonada? I recall reading it in early high school, maybe middle school. Late 70's, early 80's. It had diagrams and shit he had drawn in it. Pretty interesting.

**17K** · 05-30-21, 19:45

If the size is good for you, a 20” is nothing but advantages.

**Stickman** · 05-30-21, 21:02

ABNAK,

All I know is this, you deserve another AR, and I feel it should be a 20”….

I’m not sure how to put into words how much smoother a 20” is, but it is tangible.