45-70 & imr 7383

[Tatume]

Hello Folks,

I've seen some limited discussion of this combination, but can't find much to go on. Have any of you done much with the old Govt. cartridge and IMR-7383?

Take care, Tom

[ammohead]

Hello Folks,

I've seen some limited discussion of this combination, but can't find much to go on. Have any of you done much with the old Govt. cartridge and IMR-7383?

Take care, Tom

Tom,

I have not tried it, but I don't think that this will be a good fit. 7383 seems to do best with bottlenecked cartridges and smaller diameter boolits. 45-70 has a very large expansion ratio meaning the volume that the gas has to expand in as the boolit travels down the bore, compared to the volume of the powder in the case before firing. The volume grows much faster in proportion to the beginning volume than say a 243 would. I am only going by what I have read here and I am by no means an expert, or someone who should have the last word on the subject. But I am pretty sure that this is the case.

ammohead

[Nobade]

It leaves a lot of unburnt powder in the case, but I get amazing accuracy in my Sharps with the 535gr. Pedersoli .451 bullet paper patched to groove size over a compressed charge of 7383. Don't bother with light bullets and this powder. I get approx. black powder velocities with 7383, but less recoil.

[wiljen]

I gotta 2nd Nobade's findings heavy boolits, mild compression, still some unburnt. If you try less than about 102% load density, you will get a ton of unburnt garbage and dont bother with light boolits for the same reason - lots of trash. 7383 needs pressure to be happy so heavy boolit, heavy crimp, mild compression is the way to go.