Powder Question

[HollandNut]

I have always herd ( for the past forty years anyways ) but never tried this ..

A starting load for a cast is half the charge of the same weight jacket bullet ..

As in , say for example in my Lott , the starting load is 70 grains of a particular powder for a 500 grain bullet , then the starting load for a 500 grain boolit , would be 35 grains of the same powder ..

Anyone else ever hear this or try this ??

[shooter93]

I'd wonder about powder type a bit I think. Dropping 50% using some slow burning powders might cause serious pressure spikes like SEE. If you're looking for a low velocity load seems easier to me to just change the powder.

[wis40]

Shooter is right, under charging can seriously spike pressures as the powder actually burn backwards in some instances. IMHO you should look for a recipe that would keep your cast bullet at 1100 fps or less at the muzzle.

[lwknight]

Second that. You normally cannot use the same powder for full loads that you can reduced loads.
Straight wall cases with light bullets like 9mm have a wide range with ... say bullseye. Conversely high pressure cases require entirely different powders for reduced loads.

[prs]

No. That rule of thumb has no basis in reality; although I have admit to having zero experience with 70g smokeless charge pushing 500g loads.

prs

[bangerjim]

The rule of thumb does hold true!!!!!!!

Everybody (normally) has 2 of 'em! One left....one right.

End of rule! :drinks:

banger

[leeggen]

The op I beleive is asking about the starting load for cast in compareson to Jacketed, using the same powder. most just use the same loading imfo for cast as for jacketed as long as they are same weight and using the same powder. A reduction of 50 % sounds a little to low, and as said can cause problems. Just always start at the low end powder chcharge and work up your load. Just make sure and use same powder.
CD

[jonp]

Im not sure i would do that. Cutting H110 50 percent in, say, 44mag sounds like a bad day waiting to happen.

I also will say that i have 0 experience in 70gr/500gr charges.

[HollandNut]

well we all agree , and your answers were my answers as well before I asked the question .. I do not have the slightest clue where I herd this either ..

[gray wolf]

I have found when in doubt, the jacket start load is low enough to get started.