Q: I’d like to get my Zastava Mauser 7×57 rechambered to the 7mm Ackley Improved. I believe this was one of PO Ackley’s favourite improved cartridges, along with the .257. Will it push a 140gn bullet at 3000fps from a 24” barrel? What are the best powders for it? Could you suggest a couple of good loads for bullets in the 130-160gn weight range?
– Bruce Davies
A: When loaded to maximum in a strong, front-locking action like your Serbian Mauser, the 7×57 Ackley can safely drive a 130gn bullet at 3120fps with 55gn of AR2209; a 140gn bullet to 3010fps with 54gn of AR2209; and 160gn bullet at 2817fps with 52gn AR2209. These loads were safe in a Turkish Mauser with 24” barrel, but work up from two grains below, just in case your rifle barrel has tighter dimensions.
The picture above shows six non-magnum 7mm cartridges: the 7mm/08, 7×57, 7mm Ackley Imp, .284 Win, .280 Rem, and .280 Ackley Imp.