not sure if this is the right place for this but ..............

I was thinking about getting a SBR AR and was wondering what, if any, reliability issue go along with the shorter barrel.  I was going to go 10.5 inches. Is there a length thats "better"?  How about the buffer?  Or just ingeneral what issues SBRs have

thanks in advance for any help

Look in the Class 3 section under armory. That's the SBR forum and this is a popular question. 11.5" runs on just about any ammo. The 10.5" were made to shoot MILSPEC ammo by the military so some have reported problems when shooting low powered .223. Others have no problems shooting cheaper low power ammo after some tweaking. I chose 11.5" for just that reason.

If you wanna go SBR, in general according to Noveske, 12" barrel has the best balance of both worlds in terms of being short and handy but accurate and not to loose too much velocity to jerpardize terminal ballistic.

In terms of reliability issue, I would go with piston for sure as DI can be reliable but needs to be very well tuned and also needs to be cleaned more often than longer barrel say 14.5" or 16".

My suggestion:  LMT piston 12" MRP or cheaper option: Adams Arms piston kit

I have a 10.5" (cut down from 16") with gas port of .093" DI AR SBR.  Works great suppressed & unsuppressed with even Silver Bear ammo!

i have a 10.5'' LMT and its fantastic

if i get another upper/sbr im getting an 11.5'' because it is far more accurate for me personally

ETA: I use a heavy buffer and a heavier BCG that came with my LMT

I went 10.5" on my first one (haven't even had time to take her out yet) but will probably do a 11.5" next.  From what I've read 11.5" are a little more reliable and not as touchy about ammo.