If I want a slower load than those listed for my 257 Roberts AI, is it safe to use the minimum loads listed for 257 Roberts; I want a load that is 2500 or less

You "should" be OK. Since the AI is about 5% larger than the factory I would probably increase the minimum by that amount. But anymore I'm a belt and suspenders type of reloader.

Thanks Paul

So which is you don't trust, your belt or the suspenders?

quote:

So which is you don't trust, your belt or the suspenders?

Lost to many primers in my younger years. Don't care to push things much anymore.

what bullet? I have a speer manual with the AI data

thanks for the offer delloro, but I've got plenty of manuals, the problem is I want to try and build a low velocity load, one around 2400 and all the AI loads start >2500

I'm a little confused here, if you want to stay around 2,500 why not stay with the standard Roberts(or 259/3000) chambering? If you've got a .257Ai, whey not take advantage of it?
If your rifle has a decent length barrel, it should come close to or pass .257 Wby velocities and on less powder.
Norma MRP is what I use, 100gr. Sierra 57gr. of MRP Winchester cases and whatever brand of primer you chose. Don't start at that powder charge, work up to it. My rifle goes 3,607 with the above mentioned load
I've been called a liar on this board for this advertised velocitiy, this AIN'T BULL SHIT!
And while i'm going off the other end of the spectrom, forgive me.

Stepchild

Stepchild

Stepchild, don't blame you for being confused with me, my wife & kid have the same problem
I normally take advance of my AI, but in this case, I working on a pet project for predator hunting, I've been advised that slower velocity is the secret to less hide damage, even more important than bullet construction
I have other options (.223) but my quest for the "magical" fur-saving load has become an obsession
I plan to work up some reduced loads with SR 4759 & Blue Dot once those powders become available again up here

quote:

I plan to work up some reduced loads with SR 4759 & Blue Dot once those powders become available again up here

Loadtech shows 23.7-26.4grs of 4759 for 2400-2545FPS

then use Lee's formula for reduced loads.

quote:

Originally posted by Abob:
thanks for the offer delloro, but I've got plenty of manuals, the problem is I want to try and build a low velocity load, one around 2400 and all the AI loads start >2500

my old speer manual has 120 gr. loads at 2445, 2550, 2389, 2399, and 1523 (SR4759)

IF you are interested in 120 gr. loads. which you have not mentioned....