09-16-2013, 05:07 PM
XcountryRider Wrote:It shows the chrony is good which means the measurement of last week of Shawns Liberty barrel is good as well and it was 2655fps which matches my MV and also validates my 18in barrel MV of 2560 with 123gr Amax. I'm sure as more folks get chronys that own Liberty's and shoot factory amax as the standard we'll get more results. One question is just one batch fast or all Liberty's? Is it just the 18 and 24in barrels or are the 16in fast as well?
There's nothing confirming that these barrels are unusually fast. You have normal range velocities with factory ammo in 97 F conditions (altitude will not affect muzzle velocity either, only external ballistics past the muzzle from about 50yds on out in any measurable click value). Temperature definitely has an effect on velocity, especially with ball powders.
For an 18" barrel, 2500fps is the norm with 123gr A-MAX, some higher, some a little lower. With my 16", using a factory 123gr Scenar load in hot temps, I got readings as high as 2583fps. When I shot them later on in cooler weather, I got a very consistent 2450fps with 7fps ES, which is where that load/barrel should be. The temptation is to go around and advertise my 16" as a 2580fps capable carbine with a 123gr Scenar, but that would be misleading on my part, which led me to do some more testing with that load so I wouldn't cheat myself out of realistic drop data, and possibly reduce my bolt life.