Hi.
I have to fireform some ,257 Roberts cases to an Acley Improved chamber.
I have Hornady 75 gr bullets, N135 and N160 powder.
Cant find any data though?
Any help apreciated.
Thanks.
Ossi

Ossi... I found in the 257 AI that the maximum load in fireformed cases Rem - Peters brass Fed 210M primers and IMR 4064 to be about 48 grains. The V V 135 is somewhat similiar to that. The V V 160 is closer to the IMR 4350 and a better choice perhaps, especially if you were shooting 100 grain bullets. All that said, start low and work up... shoot safe and often. This is a tremendous cartridge, and has killed all manner of medium and light game for me on several continents.

Thanks 308 Sako, will do
Ossi