Sold the AI and found this in the safe. 615 documented rounds. Originally 20" but cut the old threads and rethreaded for 5/8x24, comes to 19.25" end to end. This is for the short action AX , not the MC. Color is Sage Green, the only color worth buying.
No change in accuracy or fps (lot to lot would have a greater effect for 3/4" length reduction). Fgmm and bha both print 1/2" at 100. Ive been digging for targets but i haven't found any and i no longer have the ai rifle.
I do all my own rifle builds so i cut the threads and shot it suppressed afterwards with no change in performance. I use a long stem indicator to zero in the bore, full profile insert and 3wire measuring to make sure its in spec.
Also this is a 12 twist as they come on factory AI barrels. Haven't had any problem stabilizing up to 178gr... haven't tried heavier.