I NEED a 10 inch AR upper in 555/223

[Ricochet]

AR pistols can be any length as long as you don't attach a stock (unless you pay the man to SBR it).

The 26" applies to long guns (min OAL). If a rifle/shotgun is made shorter than 26" OAL they become SBR or SBS and need a tax stamp to be legal.

These laws are so damn confusing.
So if OAL is above 26", can I add a regular stock and vertical fore grip?

[Wasz]

I might consider an 11 inch if I found a screaming deal, but 10 was my.performance vs length mental compromise. I understand there are drawbacks, but I have an 18 inch already and wanted something more compact. Home protection for on the road if you will.

[Ricochet]

Here's a pic of my 10.5" PSA;

AR_PISTOL.jpg

[brian]

10.5" is pretty handy. been pretty happy with psa parts.

[Wasz]

Is there any benefit to a 1:8 ratio? Is a stainless steel barrel desirable?

[danhr]

Probably goes without saying, but make sure you get a carbine length gas system over a pistol length gas system for a 10.5" barrel

[danhr]

Is there any benefit to a 1:8 ratio? Is a stainless steel barrel desirable?

1:8 is fine. From what I have read at several places on the knterwebz, most 1:7 barrels are more like 1:7.5. if you were going to be playing with 77+ grain bullets, I would say you might want to look more for a 1:7, but I'm going to assume you won't, as those grains are meant more for long distance target shooting, which you shouldn't be using a 10.5 barrel anyways for

[ExFlyinguy]

Is there any benefit to a 1:8 ratio? Is a stainless steel barrel desirable?

It's arguable. Most folks really love their 1-7.

I prefer a 1-8, or a 1-9, because I don't exclusively shoot 69-75 grain bullets.

[danhr]

It's arguable. Most folks really love their 1-7.

I prefer a 1-8, or a 1-9, because I don't exclusively shoot 69-75 grain bullets.

Maybe you can educate me on that illustration, but I disagree with the red area on 1:9 twist. I have never personally shot a bullet that heavy out of a twist rate that slow, but wouldn't you have a problem stabilizing the bullet with that setup? I think that might be a safety issue, because I have shot unstabilized bullets before, and they don't always go where you are pointing at.... Kind of a safety issue in my book

[ExFlyinguy]

Maybe you can educate me on that illustration, but I disagree with the red area on 1:9 twist. I have never personally shot a bullet that heavy out of a twist rate that slow, but wouldn't you have a problem stabilizing the bullet with that setup? I think that might be a safety issue, because I have shot unstabilized bullets before, and they don't always go where you are pointing at.... Kind of a safety issue in my book

Fair question and I can't argue your point. Obviously I didn't make the photo, & can't say who did. I'd have to consult my reloading manuals but I believe a AR is limited to 75 grain bullets. Anything bigger will not fit in the magazine due to cartridge overall length. So as you can see even a 1-9 twist is still in the yellow. I agree, if you are going to shoot 69 & 75 gn bullets get a 1-8 or even a 1-7, but I find myself shooting 55gn & 62's. 90% of the time.

My 1-8 rifle loves the 75 Hornady BTHP the 69 I can't get to group worth a crap (go figure)

Here's another popular diagram