SBR: What length?

[miles2253]

I am wanting to build an AR SBR. I thought about a 10.5" MK18ish clone but I have an oportunity to get a POF 7.25" PDW upper. I don't see myself taking a defensive shot past 30 yards or so. Would the POF have enough velocity for fragmentation with FMJ's or would I have to run SP/HP ammo with it? Should I just go with the 10.5" and forget the POF? Anyone with a 7" upper please chime in on if is actually usefull or is it more of a toy.

 

[esrice]

Should I just go with the 10.5" and forget the POF?

For me personally, 10.5" would be as short as I would go for a "serious" gun. For a "fun" gun, I'd try anything!

My Noveske 10.5" (got it out for the first time just yesterday!)

https://www.indianagunowners.com/forums/class_iii_nfa/121565-my_ar_sbr_build_in_progress-8.html

 

[Scutter01]

My wife has assured me repeatedly that size doesn't matter, but I still think 10.5" would be better.

 

[E5RANGER375]

10.5 is as short as I would go like ESRICE said, for anything serious in a 5.56

shorter and you just created a pointless toy. get a 9mm if you want to go less than 10.5

 

[ryknoll3]

I really like 11.5". Still plenty short, but the increased dwell time over the 10.5" allows for more reliability across a wider range of ammo and buffer weights.

I love my 11.5" BCM.

 

[combat45acp]

10" min here, unless your goal is a 5.56 flamethrower!

 

[cositc]

Once I save up the money I'll be getting a 7" upper for my SBR, but it's just for fun. I can take the upper off the lower and CC it in my back pocket. "5.11 Taclite pants"
My next SBR will either be a draco or a 5.5" 9mm AR, but if I can find some of the 3" barrels for the AR I might do that.

 

[miles2253]

Yeah, this was pretty much what I was thinking. That 7" upper is just cool though. I think I am going to pass on it. Thanks for the input guys.

 

[dross]

My wife has assured me repeatedly that size doesn't matter, but I still think 10.5" would be better.

Chicks lie.

 

[03A3]

It seems that most of the people with the credentials to back what they say opt for the 11.5" or 12.5" for both the reliablity and terminal performance aspects. There has to be something to that, or they wouldn't take that approach.
I don't shoot people for a living. I went with a 10.5" LMT. So far it has been flawless with real, high pressure ammo like xm193 and IMI M193.
The LMT has a small gas port, and they recommend an H buffer. I have been getting by fine so far with an H2 and a FA BC.

 

[cosermann]

Here's a table of frag velocity (2700 fps) for M193/M855 (down to 11.5" anyway):

:: Ammo Oracle

 

[Scutter01]

Chicks lie.

Hey, now, be nice. Broads don't like it when you call 'em "chicks".