High E.S on my latest range trip

S

squirrelduster

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How do I reduce the E.S. in my 300 win mag? Currently in the 30's.

All of my charges are weighed, the cases are sorted trimmed and neck turned. My current load is 73.5 gr. RE22 with a 190 gr Berger with a Federal 210M primers. Cases are Nosler.

What should I try to fix this?
 
I worked up a load this summer for a 300 win mag that was shooting 3 shot groups in the .1's (no kidding, I couldn't believe it myself) but the ES and SD's were horrible. The lowest I could get the SD's was 25 fps. I obviously had the right bullet and possibly the right powder but something wasn't agreeing. So then I swapped out the Fed 215 with a Rem 9 1/2 and BINGO. Groups stayed in the .1 to .2 range and the ES got cut in half. :eek: Amazing.
 
What chronograph and screen spacing are you using to measure velocity?
 
Spacing is 24" and the unit is a CED M2 unit. The tripod is a Leupold heavy aluminum unit. The screens are about 18 feet from the muzzle.

Good Grouper - how could you get that kind of group with a high sd ?
Sounds like your long range groups would suffer. I will try the rem 9 1/2 primer.

Lynn - I agree with your assessment of the brass prep and neck tension. I will try changing the primers and see what happens. My brother has a 300 win mag Sendoro and he shot it over the chronograph and was having the same problem. Funny he is using the same primers as I am.
I know the chrono is working correctly. I have shot my 6br with low ES and a guy shot his Chetac over it this weekend and got an ES of 14.
 
squirrelduster said:
Good Grouper - how could you get that kind of group with a high sd ?
Sounds like your long range groups would suffer. I will try the rem 9 1/2 primer.

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Click to expand...


Actually, it can happen from time to time. The harmonics of the barrel were working but the combustion wasn't happy. Sounds weird but true. SOme of the best shooting loads in 6ppc's have larger SD's (although they're usually still in the teens) than what we strive for with long range calibers.

Obviously, a load that shoots that good at 100 yards but has a high SD and ES probably won't have a prayer of shooting small groups at 1000 yards so it was never tried at that distance.
 
Change the powder

I had the same problem years ago when I first got into the 300 Win Mag. I sitched to 7828 and it got better, then a friend told me to try H4831. I have never had ES over 20. After a little tweeking I get the ES under 10 and it stays there.

Danny
 
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