Getting ES down

moosehunter

moosehunter

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My 6.5-284 shows an ES of about 30fps. Mind you my chrony has an accuracy of +-.5%. Im using H4831sc, Lapua brass and Fed 210m primers with Sierra 142mk's. Im thinking of trying CCI BR primers. Anything else. My groups are usually 2 1/2" horizontal and anywhere from 4" to 16" vertical
 
Not to be a smart ass but you have more than ES to worry about if your rifle groups 2 1/2" X 16" !:eek: :p
 
You didn't say at what range you were shooting those groups. You might be using some or most of these techniques already, but here goes -

- separate and group cases by weight (1% variance of case weight)
- repeat this procedure after each firing
- separate and group bullets by weight (half a grain variance)
- weigh all powder charges
- measure brass for run out at every stage of the loading process (try to stay within .002" total indicator run-out)
- reject brass which exceeds .003" variance in wall thickness
- uniform and deburr primer pockets and flash holes
- seat the bullets long enough to contact the lands and work up loads accordingly
- choose primers which produce reliable ignition, but the least amount of disturbance upon ignition
- chamfer case mouths to match the boat-tail angle of the bullet
- keep loading dies clean
- replace the spring shell holder retainer on your press with a rubber O ring - this will allow the case to find it's own center during resizing and bullet seating

I can probably come up with more stuff, but it gets a little questionable as to how much difference it really makes, although several things together can make a difference. Turning necks is one of those things, and much depends on the size of your chamber as to whether or not turning necks will be beneficial. Chances are that if the wall thickness is within .003 the necks won't be real bad. You could polish the inside and outside of the case necks if it makes you feel better, and there is a technique which involves putting a rubber O ring under the lock ring of the dies to allow the die to "float".
 
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I have to agree with bcsteve on that. Your 210M primers are good, CCI BR primers will not shrink your group from 16 inches. What distance are you shooting these groups at? What is the barrel count? Some serious F Class shooters will start looking for a new barrel after about 1200 rounds, when shooting the 6.5-.284. They do tend to burn barrels fast with that caliber.
I would say that the large vertical groups mean more then large horizontal if you are shooting long range and the wind is a factor. Reading the wind is important, (you won't get it right everytime) but if your rifle shoot very big vertical groups, it is time to rebarrel.
 
I found 4831 to be to fast for my 6.5 - 284, try Reloader 22 or 25, and I have switched from Federal 210M to CCI match as the Federals were not working well with the RL 25. Used to use 210M in all my varmint guns, but seem to not like setting off larger powder charges. That being said I agree with Maynard 16 " is not a primer issue, as well as the things mentioned above I would look for a bedding issue.

Andy
 
I am assuming that you are shooting at or near 1000, in which case 2.5" of horizontal spread is only a quarter minute, so wind, mirage, and gyroscopic drift aren't getting you, it's just the vertical stringing. 25 fps variation will give you about a one inch spread at 1000, so actually while your ES could be tighter, there are other things going on here. Perhaps there is a tight spot in your barrel channel which puts upwards pressure on the barrel as it heats up.

If your rifle range is on the side of a mountain, air currents could lift the bullet sharply - just like a strong gust of wind does horizontally - just prior to striking the target. Do you always shoot at the same time of day? The air might be more stable early in the morning.
 
Im shooting 1050yds. PGW M15 action, Gaillard 29" barrel 8 1/2" twist with 418 rounds. Full brass prep on the Lapua. Ive tried H4350 and its just not for my rifle. Inside necks are clean. Ive played with tension and found .003" the best. I just started playing around and learning about standard deviation last night, (I have no life). Maybe its not as bad as I thought. This year Im sorting by weight first then velocity and bullets are being done by bearing surface and getting the meplats uniformed. Hopefully that will take care of it. Reviewing a majority of my groups from last year I find that I have 3 and 4 shot groups usually under 3" and one or two which open things up considerably.
 
Extreme spread,are you getting ones out of order,beside me are my day's range results;2645,2642,2618,2649,and 2649.I'm not pleased with that lot # of CCI200s.You might try N-560
 
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Something I forgot to mention. Try shooting at 500yds. If there is vertical stringing there, then something to diagnose seriously.

If no stringing, then maybe its conditions at 1050yds????

Try another bullet.

Jerry
 
Although my Chrony Gammaster will figure ES and SD, I totally ignore those numbers.

What I rely upon is very basic. Which load puts 5- shots at 200-yards of less than 1"...

My 6.5x284 Winchester likes:
RL-22 From 42.6 grains to 51.8 grains
Federal 210 Primer

My 6.5x284 Norma likes:
RL-25 From 53.5 grains to 59.4 grains
Federal 210 Primer
 
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