Slow powders / Minimum load density

[Trapper-Jack]

Is there a constant rule of thumb where you don't want to reduce slower burning powder below - such as 60% case capacity, 70%, 80%?
Using the method described in the Lee reloading book I used 26.0 grains of Varget behind a Lee 150 grain cast bullet in a 30/06. It printed quite well for a starting point (0.85" @ 50 yards). Based on Lee's calculations it should be going just over 2050 fps. and about 21800 psi. What has me wondering is that this load is less than 50% of available powder capasity of the case. What has been you guy's experience? I have some other powders I would like to try such as IMR 4064 and IMR 4350, but I don't want to risk a detonation.
Thanks,
Jack

[1874Sharps]

Trapper-Jack,

You pose a good and interesting question. Let me say I am no expert on this subject. Might I suggest, though, that you try around 15 to 16 grains of a powder such as IMR 4227 to get you in the velocity ballpark you want.

[lylejb]

I think 4064 and 4350 are too slow to try to reduce that much.

Something that may interest you, is Hodgdon's youth load data says H4895 can be reduced to 60% of max listed load, in any caliber that it's listed for. For a better explanation see:

http://www.hodgdon.com/PDF/Youth%20Loads.pdf

also, many have used small charges of unique pistol powder, like 10-15gr, for cast loads...for decades (or more). Start light and work up till you find the best velocity/ accuracy for your gun.

hope this helps.

[Heavy lead]

IME 4064 doesn't like reduced charges, in fact, I've found it very much likes to run toward max in everything I've used it in. I'd stick with one of the 4895's, or aa2495 for reduced with cast, or something even faster.

[Trapper-Jack]

Thanks for the input. I think I'll get a pound of the 4895 and see how it will perform. Better to error on the safe side.
Thanks,
Jack