Next year I intend to use an old Win M-70 in 30-06 for Standard Rifle high-power silhouette. I plan to use a variation of the old 300 meter international load for chickens through turkeys. Currently I am using 42.5 grains of H-4895 behind a 150 grain FMJ boat tail. Shoots pretty good but velocity S.D. is high, 35 to 40 fps. Any suggestions to reduce the spread?

I would not get hooked up on S.D as the End All.
Most of most accurate long range loads do not have a low S.D. What counts is accuracy and groups at long range.
You have many powders in the same burn rate that will give you great long range groups.
In my rifles I found these powders work the best at 800 yards:
1. IMR-4831
2. Reloader-15
3. IMR-4895
4. Varget
5. WW-748- but not in cold weather
Of all the tricks and tips I have picked up and used over the last five decades I've been shooting,Neck Tension is one of the most important. If you can get every shot requiring the same force to get the bullet moving out of the case neck from shot to shot, you will see your group size shrink.
I only shoot long range.and we shoot every Sunday.

your using too little of the 4895.
it will throw high deviations as will almost any powder between H-322 and 4064 speeds at the reduced amounts.
the best way around it is to use a filler or a buffer to take up the extra room in the case.

you will need to drop the load even further [about another grain] to compensate but you'll still have the same velocity.

quote:

Shoots pretty good but velocity S.D. is high, 35 to 40 fps. Any suggestions to reduce the spread?

I have seen that much or more in factory ammo.

I don't think it is that high.

The best I ever saw was some 165 gr federal premium that was 5 fps.

Lee factory crimp die, different primers different charge different powder.

Thanks for the suggestions. I think I will start down the road Rapidrob suggested first, by annealing and neck turning the cases. See how that works, then maybe pick up a Lee factory crimp die. Actually, the load is useable as is so maybe I'm just being anal. But I have about five months before the next club match, so might just as well see how well the old 70 can do. Thanks again.

What is the sample size that you've used to determine the SD of that load in your rifle?

S.D. based on 15 round strings.

Do you know what velocity they giving? I am guessing around 2400 to 2500f/s. Are they military 150gr fmj pulled bullets?
Aneil the necks on the brass and up the load to get about 2700f/s. I shoot this load out of a M1 garand SD is about 15.

L. Rivard - you need to shoot larger samples to determine SD. The margin of error between each data point from a sample of 15 renders SD meaningless. Get SD from a sample of 50, or better a sample of 100. This will give you numbers that are starting to be statistically meaningful for your intended purpose.

he is using the load I use in my 308 in a 30-06 case.
the powder is scattered everywhere in the case.
ignition inconsistency's are what is causing the problem here.
I see it constantly with reduced loads.
the only way to fix it is to place the powder against the primer, and keep it there.

Got 100 cases annealed by the torch method and 20 neck turned. Had hoped to test today, but the rain has come and testing will have to wait a bit. Obviously the object of this exercise is reduced recoil. The 42 grain plus or minus a bit of 4895 in an 06 case has a distinguished history of accuracy in competition and is proving nicely accurate in this case too, my concern with S.D. stems from only having tested at 100 yards. If accuracy holds up at 385 meters my concern will vanish.

quote:

Originally posted by DavidReed:
L. Rivard - you need to shoot larger samples to determine SD. The margin of error between each data point from a sample of 15 renders SD meaningless. Get SD from a sample of 50, or better a sample of 100. This will give you numbers that are starting to be statistically meaningful for your intended purpose.

Totally disagree. SD isnt going to get better with more shots. Margin of error in statistics applies to the confidence level. This link shows 15 samples is not meaningless - far from it.

http://flc.losrios.edu/~eitel/...mple%20Size%20SD.pdf

Sorry for the delay reporting back, bad weather and family stuff slowed me down. Twenty rounds, neck annealed and turned to .012" yielded an average velocity of 2453 fps with an S.D. of 19. Bullets used were 150 gr Hornady fmj, not pulls. Next step is load some more and test at 385 meters. Thanks to all for the help.