Brass pressure problems in Mauser build

[vzerone]

Well I switched powders on my load I went with power pro 2000 mr starting load of 60 gr and worked up to 63 gr at 2625 fps with SD of 12.5 fps. This was only a 3 shot group. I will load more of this load and see if the SD holds. Making progress now.

What you are looking for is single digit SD'S.

[swheeler]

Well I switched powders on my load I went with power pro 2000 mr starting load of 60 gr and worked up to 63 gr at 2625 fps with SD of 12.5 fps. This was only a 3 shot group. I will load more of this load and see if the SD holds. Making progress now.

That should work on everything the lower 48 has to offer, actually Alaska too. That powder has to be in H380 or even closer to H414-W760 speed with those load densities, excellent velocity BTW. I would worry about actual accuracy on multiple targets before I looked at SD#. .02

[vzerone]

So you're telling us that ES's and SD's should be eliminated from ballistics because all that matters is the accuracy huh Mr Wheeler?

[swheeler]

That should work on everything the lower 48 has to offer, actually Alaska too. That powder has to be in H380 or even closer to H414-W760 speed with those load densities, excellent velocity BTW. I would worry about actual accuracy on multiple targets before I looked at SD#. .02

Never said that

[kfd518]

In most hunting situations many loads have been developed that are accurate to 3-400 yds with horrible sd, es figures but are quite accurate. Not that these two figures don't matter but matter much less at "normal" hunting ranges and accuracy. These two figures help to determine possible accuracy of a load if I remember correctly? May not truely show the capability of it though. Especially if not in a velocity window the rifle likes?

[kfd518]

Alliant claims it is slower than rl15. Max on that load says it pushes around 2700....
accuracy verification as well as temp sensitivity will be next

[vzerone]

They also tell you how efficiently of how your powder is burning.

[swheeler]

In most hunting situations many loads have been developed that are accurate to 3-400 yds with horrible sd, es figures but are quite accurate. Not that these two figures don't matter but matter much less at "normal" hunting ranges and accuracy. These two figures help to determine possible accuracy of a load if I remember correctly? May not truely show the capability of it though. Especially if not in a velocity window the rifle likes?

Very good summation. If you are like me most of your game will be taken under 300 yds and at those ranges your Whelen will be an excellent performer.

[kfd518]

They also tell you how efficiently of how your powder is burning.

Please educate me on determining the efficiency with these two numbers. What would be acceptable vs unacceptable? I know the aim is single digit but how do I determine efficiency with them?

[kfd518]

Very good summation. If you are like me most of your game will be taken under 300 yds and at those ranges your Whelen will be an excellent performer.

34 yds w 308 yesterday morning......that is the second shortest shot so far for me.

[vzerone]

Please educate me on determining the efficiency with these two numbers. What would be acceptable vs unacceptable? I know the aim is single digit but how do I determine efficiency with them?

You pretty much hit your own nail on the head. Yes the goal is single digits and lower single digits. When you get those low single digits you will often see duplicate readings on your chrono. But, there is more then how the powder is burning. Neck tension and crimps play a lot with it. So does internal case capacity as does bore fouling and temperature. If everything is the same on those things mentioned then each bullet should be doing near the same velocity.

I've agrued the fact a lot when you're looking at a data chart of loads and accuracy that you often see the most accurate load had the lousy ES and SD figures. Then on the other hand you see some extremely accurate groups with very low ES and SD figures.

In messing with surplus powders with booster loads that in the beginning you'll find unburned powder in both the bore and inside the case. The ES and SD figures will show high for those. So you keep adjusting the main charge and booster charge (and crimp) and when you you start to see lower figures you'll see less and less powder in the bore and case. Eventually you will have a clean bore and case and the figures will be low. Generally with cast bullets the accuracy does improve.

[vzerone]

This is a good explanation.

http://precisionrifleblog.com/2015/0...oes-sd-matter/

[swheeler]

34 yds w 308 yesterday morning......that is the second shortest shot so far for me.

That means you are a good hunter or very lucky, me I'll take luck any day! LOL Your going to love putting the "smack down" on them with the Whelen!

[kfd518]

That means you are a good hunter or very lucky, me I'll take luck any day! LOL Your going to love putting the "smack down" on them with the Whelen!

I was highly blessed yesterday. That 180 gr flopped it over in the dirt at that range I can't imagine what the whelen would have done to it. Sitting on the ground in a fence corner 2 min before sunrise. Legal hrs here are 30 min before and after. No other cover just a cedar tree to my right. He saw me raise the rifle or my scent finally hit his nose and stopped long enough to get the shot. That was the hardest I have watched one go down. But enough about that.

[vzerone]

The Whelen will kind of be like the 45-70 getting hit with a plank! Another cartidge in just about the same league as the Whelen is the 358 Winchester. Both it and the Whelen are great cast calibers. After you get settled out with the Whelen you'll have to buy a mold for it and start shooting cast. I'm sure you'll be surprised.

[M-Tecs]

Please educate me on determining the efficiency with these two numbers. What would be acceptable vs unacceptable? I know the aim is single digit but how do I determine efficiency with them?

There is no direct correlation. Low SD and ES don't become a factor until the yardage gets long for that cartridge and target size small.

A simple example is 308 in match rifles. At 200 &300 yards group size is my primary concern since poor SD and ES have very little effect on holding elevation or wind. Even at 600 the affects of poor SD and ES are limited. Moving back to a 1,000 yards poor SD and ES will cost you points.

With high velocity jacketed bullets unless the numbers are really bad I don't worry about them for 300 yards and under.

[swheeler]

There is no direct correlation. Low SD and ES don't become a factor until the yardage gets long for that cartridge and target size small.

A simple example is 308 in match rifles. At 200 &300 yards group size is my primary concern since poor SD and ES have very little effect on holding elevation or wind. Even at 600 the affects of poor SD and ES are limited. Moving back to a 1,000 yards poor SD and ES will cost you points.

With high velocity jacketed bullets unless the numbers are really bad I don't worry about them for 300 yards and under.

Exactly right! All this internet hoopala of single digit ES and single digit SD are being regurgitated by internet experts that very seldom shoot or post targets, and when they do post targets they are cropped, and we all know about that.

[vzerone]

M-Tecs You're pretty close there about what you said. Bryan Litz said that at those further distances most of the misses are from wind rather then vertical dispersion. He said that the percent of improvement between high ES's and SD'S and very low ones are a very small percentage. None the less there are no ballisticians that will tell you that low ES's and SD's don't matter.

[M-Tecs]

vzerone. We will have to disagree on that. I have shot with Bryan and a couple of other ballisticians. None of them will pick a load with low ES's and SD's that does not group well over a load that groups well with relatively poor ES and SD numbers. As the yardage increases lower ES's and SD's do become more important since it is required to hold elevation. Until you get to longer ranges than most people shoot low ES and SD simply don't correlate to small groups.

[vzerone]

vzerone. We will have to disagree on that. I have shoot with Bryan and a couple of other ballisticians. None of them will pick a load with low ES's and SD's that does not group well over a load that groups well with relatively poor ES and SD numbers. As the yardage increases lower ES's and SD's do become more important since it is required to hold elevation. Until you get to longer ranges than most people shoot low ES and SD simply don't correlate to small groups.

That's fine M-Tecs and you said so politely. I appreciate that. Now read that link I put up in post #92 Bryan Litz is partly responsible for input to that. Near the bottom you'll see where he himself said what I posted in post #98. I'm going to hang with him. I respect his knowledge a lot.