N570, H1000 or Retumbo accuracy differences?

[K.E.C. Darkside]

You can change primers and powder.
And it typically will change your poi.
If you like your powder then change your primer. Or vice/ versa.
And you can try pushing them a little harder, but only you can make that call.

 

[Sierra6]

I'm curious if you have enough twist rate. What is your twist rate?

 

[journeymanwirecontrols]

I've got plenty of different powders, but I am currently limited to WLRM primers.

Ya, I hear that, we're all probably a bit shy on primers, I haven't done any load development in three years because of the shortage.
As a few others have stated try a different powder, that could do it for you. I am curious and others are too, what is your barrel twist rate, it may not be tight enough to spin those 245's or the 250's. I only have a 1/10 twist in my rifle so all the heavier I can go is the 225 to 230 projectiles. I hope all this helps.

 

[Laguna Freak]

I worked up my load in 0.5 grain increments until I hit pressure and then I backed off a little. The highest charge also coincided with my best group. I played with seating depth some but didn't see any noticeable change. Mag length limits me to 0.018 off the lands. The ADG brass is on its second loading.

74Honker is spot on.

It sounds like you did not conduct any powder charge ladder tests. If I were in your shoes, I would likely back off 1.5 grains from where you hit high pressure, start seating depth at 0.060" off the lands and shoot 0.1 grain charge increments at the same PoA back up to pressure. Be sure you log PoI. You should hit pressure quite a bit lower with deeper seating.

FWIW; I've found 30 cal Accubonds and Scirocco II of various weights from 150 to 210 grain perform better from 60 to 70 thou off lands in my Bartlein, Brux, Winchester, and Steyr barrels.

 

[Ronald W Schaefer]

I'd try the different powders and maybe play with seating depth, but most likely, your rifle just doesn't like that bullet.

 

[Ronald W Schaefer]

By the way has anyone seen RL-26 on sale anywhere?

 

[jlphillips1]

I'm curious if you have enough twist rate. What is your twist rate?

1.8

 

[jlphillips1]

Ya, I hear that, we're all probably a bit shy on primers, I haven't done any load development in three years because of the shortage.
As a few others have stated try a different powder, that could do it for you. I am curious and others are too, what is your barrel twist rate, it may not be tight enough to spin those 245's or the 250's. I only have a 1/10 twist in my rifle so all the heavier I can go is the 225 to 230 projectiles. I hope all this helps.

My barrel is a 1:8 twist so it should stabilize the 245 Bergers. I loaded up some with N570 and I'll post the results when I shoot them this Saturday. Thanks for all the advice.

 

[Sierra6]

1.8

That's more than enough. Sounds like you have a plan moving forward.

 

[Shane Lindsey]

Not a PRC, but a 300 RUM with the 245 Berger EH. Don't be afraid to seat them deep. In my RUM I loaded to fit in an AI mag at 3.745" which jumped at .157" off the lands (like the Grand Canyon jump). Another was .98" jump. Even tried single feeding at .010" off and settled on the shortest even after going back to the Wyatt's box. Looks silly, not sexy, but it just works.

Have you got the group size you want with any powder yet? Not velocity/group size? I ask because Berger data was 2769 FPS/87.8gr N570. I get a little better than that at 2845 FPS with N570, but that is a RUM. Your PRC should be about there with +p.

I would drop down a bit with H1000. Or go to N570 and see how it does. I get great accuracy with it. Haven't tried H1000 in this barrel because the N570 did so well. I did get about 100+ FPS difference in a 300 WM FWIW.

 

[parshal]

76 grains of N565 worked best in my PRC with the 245's. ~2825 fps and it's probably the smallest group shooting rifle I own including a Dasher and BR. 78 grains gave me 2900 with good SD/ES but 76 shoots bugholes.

 

[Rich Coyle]

Before switching, try a different primer.

 

[Axl]

It shot 1/2 moa groups with the 215 Bergers, but I don't like that bullet for hunting.

1/2 moa with 215 Berger's is the holy grail of elk hunting. I have seen no bullet work as well, and it is what I had my custom 30 Nosler built to shoot.

 

[jlphillips1]

So the N570 performed much better than the H1000. See the chart below that I created from the data (blue is moa and orange is ES). I'll have to load up some more around that 79 grain node and see where the sweet spot is. I shot this at 500 yards. Notice that the lowest ES also corresponds to the lowest moa.