257 Roberts Ackley Improved

[tdoyka]

i might be getting rid of my tc venture in 25-06, reloading dies, and 80 some pieces of rem brass. i'll be buying a encore in 257 Roberts Ackley Improved, 1 in 10" twist, in a 21" mgm barrel. i sent an email to mgm barrels to make sure it has a 40 degree shoulder, so that is taken care of. i have 2 full boxes of 115 grain nosler ballistic tips. do these work for deer, busting a shoulder, etc, or should something else work?
is there a fireforming load? or will just shooting, like 100gr hornady spire point with imr4350 36.8gr(low load for hornady 257rob) or something else?(100gr hornady sp point with imr4350 40.7gr low load for 257rob ai)
using 257rob +p winchester for the fireforming, my first time as a ackely imp guy!!!

thanks!!!!

 

[Mobuck]

If the AI chamber is properly cut, about any 257 load should be fine. If you end up having to seat the bullets against the lands to maintain proper headspace for fire forming, the lighter loads would be advised.
I have a 257AI that was cut about 1 revolution of the reamer too deep so I have to seat long bullets into the rifling to get the AI shoulder pushed slightly forward.

 

[reynolds357]

I fire form all my Ackley stuff the same way I form my true wild cat chambers. I use pistol powder, shotgun powder, whatever other fast powder I have handy and cram pieces of wax or cloth in the case neck fill with grits.When a bunch of us are making brass, the range looks like it snowed from 15 to 25 yards.

 

[pathdoc]

Forgive me for my ignorance, but I always thought the thing about the Ackley Improved chamberings is that they were back-compatible with factory ammo?

 

[reynolds357]

They are. I am not going to waste a bullet doing what a bit of grits will do.

 

[old roper]

On my Ackley varmint rifles I fireform shooting PD and others I'll use same method as reynolds357. Not so much wasting bullet as wear on the barrel with no benefit.