Reloading the .30 Ackley #1 Short Mag.

[MW3840]

Has anyone out there formed .30 Ackley #1 Short Mag. out of anything other than from .300 H&H Mag. brass?

Curious, as I don't want to have to spring for a form die that's over $100.

I used 7mm Mag. brass which I first ran through the .30 ackley sizing die, fire formed, than loaded with180 gr. Nosler Partitions, but accuracy was a dismal 9" group at 100 yds. and 50% of the shoulders split after the 1st loading.

Thanks,
Mike

[rexherring]

Are you annealing the cases first before sizing? If I don't do that when forming my improved cases about half will split.

[MW3840]

No I'm not Rex, although I thought of that also. But do you think that would make a difference in the group size?

[HangFireW8]

Neck tension affects group size more than head space (assuming boolit jump is the same). If your neck tension is all over the place, accuracy will be poor.

I annealed cases for my 257AI, but I found that getting them red hot was problematic- they were so soft after fireforming, the shoulder would collapse when I seated a boolit/j-word.

Through experimentation I found that very moderate annealing was sufficient for both good fireforming and sufficient strength.

HF