I haven't seen a lot of data out there for short barrels. This is data from my 12" 1:7 FN "firearm" (pistol lower w/FVG). For comparison, the same loads through a 16" S&W carbine produce ~200 fps more velocity. All samples were (6) 5 shot groups (30 total) with temps ranging from 62 to 76 degrees.

Federal M855: 2773 fps 1058 ft/lbs SD=31

60g Nosler Ballistic Tip, 25.0g H335: 2711 fps 978 ft/lbs (2.26" OAL) SD=18

55g Hornady FMJBT (bulk), 25.0g H335: 2768 fps 934 ft/lbs (2.20" OAL) SD=25

The 60g Nosler load is just about maxed out. Barely flattening the primer radius. The 55g Hornady load could go higher; I just use it for plinkin'. Haven't played with it much since I shot these - it has a new "big brother", an 11.5" 300 AAC that I've been working on developing loads with.


That is all...