I'll start by saying between my rifles and a few buddies rifles we have extreme spreads in the single digits and teens in multiple .308's, .300 wsm, .300 rum, 7 wsm, and .338 Lapua. Myself and one other buddy are fighting hard to get good es's on our .300 win mags. We are shooting 230 hybrids and h1000. His rifle shot a 3 shot 100 yard group at .030" with 73.2 grains and .020" jump with a fed 215m. My rifle shot a 3 shot 100 yard group that measures .098" with 74.4 grains h1000 and 230 hybrid .020" jump with a cci 200. In both rifles we have tried cci 200/250 and fed 210m/215m. It doesn't matter what we try, our es's are all over the place. Anywhere from 30-60. All brass has been match prepped and using inside dry neck lube. Using the same loading techniques I always have on all other rifles. Where do I go from here? I have about 20 lbs of h1000 and that seams to be the go to powder that others are getting to work. I see no reason why I can't get (2) .300 win mags to get a decent Es. Any ideas? Thanks
.300 win mag ES issues
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You may not be as bad as you think you are. I usually worry more about the SD of a load than the ES. ES identifies only the outliers, the worst case scenarios, maybe there's only one. It could be a number of things, primer, neck tension, ect. What is the cold bore SD of the load over a period of at least 10 cold bore shots. Seldom will you get more than one precise shot on game.
One of my rifles found the narrowest SD with Winchester LR primers. Two use CCI LR 200, one uses federal 215m, three use federal 210m. Every rifle is slightly different and those two rigs may not dig the same groove, so to speak.
One of my rifles found the narrowest SD with Winchester LR primers. Two use CCI LR 200, one uses federal 215m, three use federal 210m. Every rifle is slightly different and those two rigs may not dig the same groove, so to speak.
ShtrRdy
Well-Known Member
What kind of dry lube do you use?
WildRose
Well-Known Member
Broad swings in ES are usually attributable to inconsistent pressures which can result from inconsistent burning due to weak primers, inconsistent neck tension or inconsistent seating depths at least in my rifles.
You can also get broad swings when simply changing from one can (even of the same lot number) to another.
Are you guys measuring each load carefully on a consistent scale or are you using a powder dropper and only occasionally checking them for consistency? The latter can certainly bite you in the tail occasionally.
Also, some rifles simply seem to like one powder while another likes others.
You might try some RL-33 or RL25 and see what that does for you or perhaps just moving to a different primer or two first to see if you can get more consistent ES.
You can also get broad swings when simply changing from one can (even of the same lot number) to another.
Are you guys measuring each load carefully on a consistent scale or are you using a powder dropper and only occasionally checking them for consistency? The latter can certainly bite you in the tail occasionally.
Also, some rifles simply seem to like one powder while another likes others.
You might try some RL-33 or RL25 and see what that does for you or perhaps just moving to a different primer or two first to see if you can get more consistent ES.
Each charged is perfectly weighed out and the seating depths are consistent. Powder from the same jug. Ive tried 210m, 215m, 200, 250, and br2 primers. Ive been through 150 rounds now trying to get a decent load. The rifle will shoot in the 0's and .1's but I can not get good es's.
dsculley
Well-Known Member
You said 3 shot groups from .030" to .098"? Forget what your chronograph says about ES. As said earlier, SD is a MUCH better predictor of bullet performance. With that said, if i were shooting groups like those I would not be concerned with either ES or SD from my chronograph.
As Capt. RB said, shoot it at longer ranges and see what happens. If your vertical increases proportional the vertical in your 100 yd groups then you don't have an ES or SD problem.
FWIW, I will always defer to what I see on my target. You don't say what chronograph you are using. Some are better than others, but most are really only a good estimation of MV. If you want to know your true ES as apposed to the ES of that group then multiply your SD by 6.
I shoot a group (usually 10 shot group) at a long enough range to have some dispersion in the group (as opposed to a "cluster" at 100 yds, I want to be able to identify all shots) then measure the vertical and horizontal dispersion, use this to compute SD for the entire shooting system (this includes the shooter when using this method) to see what size group I can expect at any range.
FWIW,
As Capt. RB said, shoot it at longer ranges and see what happens. If your vertical increases proportional the vertical in your 100 yd groups then you don't have an ES or SD problem.
FWIW, I will always defer to what I see on my target. You don't say what chronograph you are using. Some are better than others, but most are really only a good estimation of MV. If you want to know your true ES as apposed to the ES of that group then multiply your SD by 6.
I shoot a group (usually 10 shot group) at a long enough range to have some dispersion in the group (as opposed to a "cluster" at 100 yds, I want to be able to identify all shots) then measure the vertical and horizontal dispersion, use this to compute SD for the entire shooting system (this includes the shooter when using this method) to see what size group I can expect at any range.
FWIW,
Okanogan
Well-Known Member
You might want to take a look at Bryan Litz's new book, Modern Advancement In Long Range Shooting Vol 2 as he has an interesting section on reloading variables and impact on MV consistency. If I remember right the short versions might be something like neck tension had low influence, powder fill % was inconsistent influence and the chapter relates an issue with 300WM and another caliber where changing primers made a significant improvement to SD.
It sounds like you have already tested a range of what would be considered reasonable quality primers in your testing and your reloading process sounds solid to me anyway.
My own ES/SD with 300WM are not as good as with 308 and 30-06 loads. The best I've been able to do with the 300 WM is try different combinations of powder/ primer and charge weights with different bullets (Berger and ELDX mostly for 300WM). I tend to do better consistency with near maximum loads with bullets 190gr+ bullet weight. Even then I don't seem to get single digits SD even though I am doing the same case prep and methods as with the 308 & 30-06 precision loads. Trail and error combinations of powder and primers has gotten me to SDs of 10-15 fps with the 300wm fairly consistently.
While I can't offer an easy solution to your issues, I will be interested in following the thread to see what others suggest. And again, I'd suggest you check out the relevant sections in Litz's new book as an objective data source for your efforts.
It sounds like you have already tested a range of what would be considered reasonable quality primers in your testing and your reloading process sounds solid to me anyway.
My own ES/SD with 300WM are not as good as with 308 and 30-06 loads. The best I've been able to do with the 300 WM is try different combinations of powder/ primer and charge weights with different bullets (Berger and ELDX mostly for 300WM). I tend to do better consistency with near maximum loads with bullets 190gr+ bullet weight. Even then I don't seem to get single digits SD even though I am doing the same case prep and methods as with the 308 & 30-06 precision loads. Trail and error combinations of powder and primers has gotten me to SDs of 10-15 fps with the 300wm fairly consistently.
While I can't offer an easy solution to your issues, I will be interested in following the thread to see what others suggest. And again, I'd suggest you check out the relevant sections in Litz's new book as an objective data source for your efforts.
I'm using a magnetospeed. Same chrono I've used with other calibers. If the weather is decent this weekend I'll shoot a group on paper 6-800 out and see what verticle looks like. at 1000 yards the difference between 30 fps fast and slow round is .75 Moa. That's a pretty big difference if your trying to hit a deer or antelope. Thanks for all the help.
Okanogan
Well-Known Member
Arrow... From the data in Litz's book, I personally wouldn't chase neck tension as a high priority in trying to track down an ES/SD improvement. My opinion is that other than consistency in the load process, which it sounds like you are doing, it requires getting the right combination of primer, powder and bullet for the specific rifle to get a good clean full burn each shot. My experience seems to match your own in that doing this for 300WM seems more challenging than for some other calibers.
Another resource you might consider checking out would be Precision Reloading Guide by Dave Brennan. It was mentioned on the Precision Rifle blog as a particularly good reloading resource. It is out of print but I managed to get a loaner copy from my local library. I seem to remember that it mentioned things like hand seating primers to improve consistency in seating depth/ seating pressure and a few other tricks that may help in a challenging situation.
Another resource you might consider checking out would be Precision Reloading Guide by Dave Brennan. It was mentioned on the Precision Rifle blog as a particularly good reloading resource. It is out of print but I managed to get a loaner copy from my local library. I seem to remember that it mentioned things like hand seating primers to improve consistency in seating depth/ seating pressure and a few other tricks that may help in a challenging situation.
The thought just occurred to me that neither of our .300 win mags have had the necks turned. We're using norma brass which is pretty consistent but I just realized that all these other calibers I'm getting good es's in are with turned necks. Do you think by uniforming all the necks' thicknesses this could help es's?
