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Hello,

For my 7mm08, I'm switching from Hornady cases to Lapua cases. The Hornady case holds 56.9gr of water and the Lapua case holds 53.9gr of water.
If my pet load in the Hornady case is 47.3gr of powder (published max is 48.4gr), what should I load in Lapua case to duplicate it? I know it may not be as accurate as the Hornady case load I was using, but I figure it is a good place to start.

Does this look right?

53.9/56.9=.9472

.9472x47.3=44.8. new load is 44.8?

I took your formula and plugged into Quickloads.

Back off 1- 1.5 grains. Current load is using 83% case fill. -1.5 grains in new brass would be 84% case fill. Should be close.

I loaded the 44.8, velocity was 2940 fps (Lupua case) with the 120gr Barnes TTSX. My old load (Hornady case), velocity was 3040 fps, but the new load grouped 1/2", best I could do with the old load was 3/4" and most of time around 1". This new load works for me, I don't care about 100 fps less, it grouped better, and it should drop deer and hogs just as good. Thanks for running the numbers.

Looks like your new load is working out for you. Happy hunting.

Sounds like you got lucky and landed on a pretty good node. When you say 1/2", was that a single 3 shot group?

Hell yeah, that's good and the case capacities are a moot point at this time...but, case capacities should be measured with fireformed brass just in case someone wasn't aware of that fact.

I think an accuracy improvement of that magnitude is well worth the 100 fps tradeoff, but "just because," I guess. I'd bet the velocity difference and the accuracy difference both amount to nothing for about 98% of practical uses. But that's rational thought, and we're handloaders.

Sounds like you got lucky and landed on a pretty good node. When you say 1/2", was that a single 3 shot group?[/quote]

I did get lucky, first group (3 shots) out of a cold barrel (gun out of the safe, ran a dry patch down the bore) was about 3/4". Sat the 7mm aside, shot a group with my 308, checked a few things on my cell phone until the barrel was cold and then shot another group with the 7mm, that one was 1/2". Adjusted the scope some, sat it aside and shot the 308, waited for 7mm barrel to get cold, and shot another 3/4" group, then put it away for hunting season. Both guns are Brownings, the 7mm-08 is a old A-Bolt, been with me a long time and is beat up. The 308 is a new X-bolt, nice gun, funny thing is, the old A-bolt, right out of the safe, no fouling shots, it shoots pretty good, the X-Bolt likes a few fouling shots before the groups really tighten up.