Am looking to go SBR, what barrel length should I go with other than 14.5"?
Depends on a lot of other factors… what you want it for… Do you plan on a silencer for it?.. etc.
I’d register it for 10.5" or 10.3". That way you always have the option of running the shortest barrel configurations.
Both 10.3/.5 & 11.5
Not looking to use a silencer, just want a compact rifle.
Is one short barrel length more reliable over another?
Not IMO if unsuppressed. The gas system on both is the same length. Beyond the FSB you may run into prob’s with baffle strikes if running a can on a barrel less than 11". Depending on the brand you go with since the gas port size may differ, you may need to run a heavier buffer and/or extractor upgrade & they may be more ammo specific. Other than that they run the same as a 14.5> (at least for me) but are MUCH louder than the longer barrels. I’d recommend CMMG or BCM for 11.5’s & CMMG or LMT for 10.3/.5’s or a Colt if you can find one.
Get yourself an LMT 10.5 inch complete upper. Completely reliable suppressed, unsuppressed, semiauto, fullauto. Mine is 100% reliable with an H2 buffer; close to 4k rounds through it and I feel like it is just now broken in.
I run 10.5", 11.5", 12", 14.5" and mine are reliable with or without suppression. My observations regarding other’s weapons tend to indicate that generally speaking the most reliable ones are in the 11.5" - 14.5" range. These are first hand observations, with the understanding that I have no control on the parts selection, care and feeding that others impart on their weapons. As barrel length gets shorter, the wear/tear on parts becomes accelerated. There are other instructors that visit here with much more experience and see a greater number of weapons in classes each year than I. They can give you more insight accordingly.
Of the commonly available lengths, I recommend 11.5" carbine barrel due to it’s good combination of gas system dwell time and short barrel length.
OK, 11.5" it is.
Ordered paperwork from ATF and am in the process of getting lower engraved ahead of time.