01-01-2014, 05:15 AM
XcountryRider Wrote:20in barrel gets over 2500fps with 125gr Nosler BT.
If we are still comparing against the Blackout you wonder why no Blackout barrels are produced longer than 16" by any manufacturer. A longer barrel gets you more velocity, but at the expense of having to tame subsonic rds below the speed of sound. It is likely the dwell time for your longer barrel will force you to push the gas block out further which is counter-productive in an under-gassed system like a 30cal barrel. The larger diameter barrel drops the cycling pressure a lot quicker than 6.5 and .223. Current wisdom is to bring the gas port in as close as possible which makes the idea of a barrel longer than 16" problematic.
If supersonic is all you want then cycling pressure and dwell time is a lot easier to manage, and then a more realistic comparison for the 30ARX is the Grendel, not the Blackout.