257 Ackley

[fps plus]

Anybody else playing with this cartridge. I have one and it surpassed 3200 FPS with 100 gr bullets . It appears to be a dandy improvement over the std 257 Roberts

[Altaboy]

I built one last summer. Never got to 3200 though.

[Dubious]

Have had a 25-05ai with 70gr bullets just short of 4000fps but it wasnt accurate enough dropped down to a more reasonable 3600fps and doing a bughole group that’s my go to for gofers now.

[rembo]

I'd just do a 25-284.
No fireforming required when necking down 6.5-284 brass and the case is shorter than the Roberts case which is a plus for short action mag boxes.

[fps plus]

Originally Posted by rembo

I'd just do a 25-284.
No fireforming required when necking down 6.5-284 brass and the case is shorter than the Roberts case which is a plus for short action mag boxes.

Yes it’s a good one as well . I have the Tee shirt. Feeding is an issue with the 284 case , especially in a long action

[rembo]

Originally Posted by fps plus

Yes it’s a good one as well . I have the Tee shirt. Feeding is an issue with the 284 case , especially in a long action

I have the reamer and have done four IIRC. Feeding in short 700's can go either way. I did one in a Model Seven that fed just fine as is. One old 700 from '69 needed the bumps removed form the sides of the feed ramps and then it was very good at feeding. Actually I remember now I did 2 in Model Sevens.

I have a set of 6mm-284 dies and have been contemplating trying that one. Need a reamer.