N570, H1000 or Retumbo accuracy differences?

[jlphillips1]

I've got a Bergara HMR pro in 300 PRC and I'm struggling to get the 245 Bergers to do better than 1 MOA. I'm currently loading them in ADG brass with H1000 and my average velocity is 2870. I've had the +P treatment done on my barrel to get the extra velocity. My question is that I want to keep this bullet/velocity, but 1 MOA is not good enough. I have plenty of N570 and Retumbo and I should be able to match the velocity or maybe even get a little more, but will I see any improvement in accuracy with these powders? All of these powders perform similarly, so I'm not sure I would see any change in accuracy. What do y'all think?

 

[jraulsten]

Every barrel is different. You just have to try them out. My 300 PRC loved N570 while a friend's would only shoot H1000.

 

[Ckleeves]

Powder change can either have a big affect or none at all. You pretty much have to try it to find out. I like H1000 and load lots of it, but some guns just prefer RL26, N565 or Retumbo. With a 245 I think I would probably go straight to the N570 and give it a try.

 

[74honker]

Every barrel is different. What will work in one may not in another. The rifle always decides what it wants, powder or bullet. More info on your proccess to this point, ie have you tried fine tweeks to charge and or seating depths, new or fired brass etc? Then again some guns just wont shoot period, all part of the fun and journey.

 

[Dmagna]

My 300 prc hates n570. Shoots h1000 lights out

 

[jlphillips1]

Every barrel is different. What will work in one may not in another. The rifle always decides what it wants, powder or bullet. More info on your proccess to this point, ie have you tried fine tweeks to charge and or seating depths, new or fired brass etc? Then again some guns just wont shoot period, all part of the fun and journey.

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]

If it were me, I would try a seating test at longer jumps like .040, .050, up as far as .100 or better. If a bigger jump didn't work it's time to move on. As others have said a change in powder may or may not help just have to try it. If powder changes don't help it's time to change bullets. Another thing to do if this is a consistent issue would be to go over the gun. Make sure everything is solid and torqued.

 

[mandl]

My +p barrel in 300 prc shot 245's excellent with 570. But, had to seat them just off lands which made them too long for mag. As I seated into magazine and deeper, my groups totally fell apart. My magazine if I remember correctly is 3.965 max. The excellent groups with 245's were 3.985 coal. I'm betting you will have same problem with Bergara mag. Unless you wanna run it as a single shot.

 

[APDDSN0864]

I have two 6.5x280AI rifles, both cut with the same reamer, headspace is the same, twist rate is the same, just different barrel makers.
One loves Retumbo with 140 gr bullets and will not perform the same with RL26, the other is just the opposite.
Neither of them prefer H1000.

Fortunately, I just restocked my stash with fresh Retumbo and RL26, so I'm good to go.

Ed

 

[journeymanwirecontrols]

You should try two or more different primers with this load also, no matter what bullet/powder combo I try when I'm doing load development I usually try 2 or 3 more primers and look at the results. With bigger powder charges and cases they have made a big difference, your load will open up even more or close up tighter and then I know what primer works best with the powder/bullet/case/primers combo I'm working with, and I always test with a five shot group when doing this.
Have a great day.

 

[Axl]

Different powder might be better, it's also possible it's a 1 moa gun.

 

[jlphillips1]

My +p barrel in 300 prc shot 245's excellent with 570. But, had to seat them just off lands which made them too long for mag. As I seated into magazine and deeper, my groups totally fell apart. My magazine if I remember correctly is 3.965 max. The excellent groups with 245's were 3.985 coal. I'm betting you will have same problem with Bergara mag. Unless you wanna run it as a single shot.

I started at 0.40 and went in 0.03 increments with no noticeable change. If I tried 0.50 or longer I would probably need to back off on my charge. It's a heavy rifle but I still consider it a hunting rig and I don't want to single feed bullets. I might try a few a little off the lands just to see if it would change the accuracy.

 

[jlphillips1]

Different powder might be better, it's also possible it's a 1 moa gun.

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

 

[jlphillips1]

You should try two or more different primers with this load also, no matter what bullet/powder combo I try when I'm doing load development I usually try 2 or 3 more primers and look at the results. With bigger powder charges and cases they have made a big difference, your load will open up even more or close up tighter and then I know what primer works best with the powder/bullet/case/primers combo I'm working with, and I always test with a five shot group when doing this.
Have a great day.

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