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300 Win Mag and N570

What cases? You could also be over pressure. My ES was higher with more N570. Drop it down to the 78 ish range if using ADG. 80ish if using Norma. When you find the sweet spot it will sing, but then you will have eaten your throat and need to adjust 🤣

H1000 in the 2850 range is a happy place.
I'm loading Norma Brass. At the range, another shooter gave me a bunch of Federal brass. It weighs 30 grs more than the Norma brass.
 
BTW I'm using new Peterson long brass and did see slight ejector marks at 79 & 79.5gr no stiff bolt lift. The new long brass compared to 1X fired Remington factory brass in this chamber is .004" longer using a Hornady headspace comparator. I did OCW testing with H1000 and N570 in .5gr increments and the N570 was very consistent with 4 out of 6 CWs under MOA @ 100yds while the H1000 had 2 out of 6 under but had the most accurate 3 shot grp @ 0.137". The H1000 showed pressure signs 100fps slower than N570. Also, I did the mfg recommended barrel break in procedure on the barrel before doing any load testing (32 rnds). The barrel did show better accuracy as it broke in.
 
BTW I'm using new Peterson long brass and did see slight ejector marks at 79 & 79.5gr no stiff bolt lift. The new long brass compared to 1X fired Remington factory brass in this chamber is .004" longer using a Hornady headspace comparator. I did OCW testing with H1000 and N570 in .5gr increments and the N570 was very consistent with 4 out of 6 CWs under MOA @ 100yds while the H1000 had 2 out of 6 under but had the most accurate 3 shot grp @ 0.137". The H1000 showed pressure signs 100fps slower than N570. Also, I did the mfg recommended barrel break in procedure on the barrel before doing any load testing (32 rnds). The barrel did show better accuracy as it broke in.
570 adds 50-150fps over nearly other powders. Usually I'll get within 35fps with 33 and about 50fps with lrt. If you want velocity go with vv powders as they'll out run 26 and 23. Accuracy.......well maybe not, but still could be. Newton test against hd and grand for comparable vv powders.
 
Is it possible you are way overpressure. I am shooting 72.5 gn and I'm at 2920fps. I know every rifle is different. I'm using adg brass
With N570? I ran mine up to 80 grains before I couldn't possibly squeeze in any more powder. And at 2,600 FPS, there's no way he's over pressure
 
Is it possible you are way overpressure. I am shooting 72.5 gn and I'm at 2920fps. I know every rifle is different. I'm using adg brass
I'm using Norma Brass. I have zero pressure signs. Another poster said, "N570 doesn't like under pressure; I should be getting 3,000 with that powder bullet combo."
 
Your COAL needs to be at least 3.6" with n570. If you loaded to SAAMI specs, it's going to run slow because you're not getting enough pressure. Seat that bullet out further and fill the case with powder. You almost can't pressure out with n570 in a win mag case. It's a bulky powder so you're going to get powder crunch but I keep going up by .5 until the bullet springs out of the case by .005-.010"
That's interesting,COAL now is 3.525. I'll try that.
 
I believe the consensus is to try another powder if you are looking more speed! Plenty of suggested powders here that should achieve that for you. Good luck!
 

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