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Old 08-09-2011, 09:47 AM   #1338 (permalink)
MacCool
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Quote:
Originally Posted by ImportConvert View Post
The shorter the barrel/gas-system on an AR, the worse it performs, in general.
Once you get below about 11.5 inches, gas systems can get a little finnicky due to the decrease in dwell time. An 11.5 inch SBR has about a 40% greater dwell time than a 10.5, so 11.5 and above---no problem. Add a suppressor, things can get a little more complicated, solved with an adjustable gas system like the Switchblock.

As to performance, I lose about 250 FPS with my 11.5 compared to my 16 inch using PMC .223 ammo in 55 gr. Since my SBRs are entirely for shooting at 50 yards or less, there is no meaningful performance degradation for my purposes. YMMV. For those who want a rifle to shoot out at 100 yards and beyond with MOA accuracy, an SBR wouldn't be the best choice.



Quote:
Originally Posted by ImportConvert View Post
All true, but I don't feel a need for an SBR.

That, of course, is the bottom line. The reason I persist on the subject is that I wouldn't want anyone to get inaccurate impressions.


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Last edited by MacCool; 08-09-2011 at 10:11 AM.
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