257 Roberts Ackley Improved

[JeffreyDeGraff]

Going to find my max load, with three different powders, for Nosler 115gr ballistic tips. Rifle is an FN supreme with 24” ER Shaw barrel. Remington brass, Winchester primers, bullets are .006” off the lands. The powders I chose are RL19, H4831, and IMR4350. Ive loaded one round for each charge weight, going up in .5gr increments. RL19 - 47.5gr, 48.0gr, 48.5gr, 49.0gr, and 49.5gr. H4831 - 46.0gr, 46.5gr, 47.0gr, 47.5gr, and 48.0gr. IMR4350 - 42.5gr, 43.0gr, 43.5gr, 44.0gr, and 44.5gr. When the weather warms up a little I will hit the range and see what happens. Report to follow.


JTD

[Wes Sage]

Nice!!!
Love my 257 AI

[SAWMAN]

It is a great chambering. Super efficient.
How do your vels compair to a 25-06 or a 25-06AI ?? --- SAWMAN

[Wes Sage]

Don't know since I don't do 25-06, but I can get a 75gr bullet to do almost 4000 FPS, and have pushed it over that a few times

It is a great chambering. Super efficient.
How do your vels compair to a 25-06 or a 25-06AI ?? --- SAWMAN

[JeffreyDeGraff]

I’m embarrassed to say, the two loads I previously shot out of this rifle (both 100gr) were never chronographed. This time around I will have some numbers.


JTD

[SAWMAN]

I am interested in quite a few AI's and have been shooting them for some time now.
My wife is still hunting with her 30-30AI that I built up for her some 35 years ago. I am really surprised that all are still wildcats. --- SAWMAN

[JeffreyDeGraff]

It is a great chambering. Super efficient.
How do your vels compair to a 25-06 or a 25-06AI ?? --- SAWMAN

Even though I’ve never chronographed anything out of this rifle, one of my standard 257 Roberts shoots 117gr hornady at 2850fps. I will be using that number as my base line for this work up.


JTD

[JeffreyDeGraff]

Finally made it to the range. Had some interesting results. None of the loads showed any pressure signs, primers were fine, easy extraction. Results were as follows. RL19- 47.5gr 2920fps. 48.0gr 2983fps. 48.5gr 2997fps. 49.0gr 3024fps. 49.5gr 3067fps. H4831- 46.0gr 2866fps. 46.5gr 2901fps. 47.0gr 2926fps. 47.5gr 2933fps. 48.0gr 2983fps. IMR4350- 42.5gr 2825. 43.0gr 2844fps. 43.5gr 2883fps. 44.0gr 2922fps. 44.5gr 2933fps. What I found interesting was that 48gr of RL19 and 48gr of H4831 had the same exact velocity (granted it was one shot with each). The thing that I found the most interesting was that 12 of the 15 shots went into a 1.050” group, that’s 12 shots no two rounds the same, all different charge weights and powders. I feel like load development for this one is going to be a breeze.


JTD

[Wes Sage]

That is awesome!!! I had the same thing with mine!!
I was able to get a 75gr bullet to 4000+ Fps, and no matter what they were all in 1" at 100

Finally made it to the range. Had some interesting results. None of the loads showed any pressure signs, primers were fine, easy extraction. Results were as follows. RL19- 47.5gr 2920fps. 48.0gr 2983fps. 48.5gr 2997fps. 49.0gr 3024fps. 49.5gr 3067fps. H4831- 46.0gr 2866fps. 46.5gr 2901fps. 47.0gr 2926fps. 47.5gr 2933fps. 48.0gr 2983fps. IMR4350- 42.5gr 2825. 43.0gr 2844fps. 43.5gr 2883fps. 44.0gr 2922fps. 44.5gr 2933fps. What I found interesting was that 48gr of RL19 and 48gr of H4831 had the same exact velocity (granted it was one shot with each). The thing that I found the most interesting was that 12 of the 15 shots went into a 1.050” group, that’s 12 shots no two rounds the same, all different charge weights and powders. I feel like load development for this one is going to be a breeze.


JTD

[JeffreyDeGraff]

That is awesome!!! I had the same thing with mine!!
I was able to get a 75gr bullet to 4000+ Fps, and no matter what they were all in 1" at 100

Thanks Wes. There must be some magic involved!


JTD