Mr. Howell,

I shoot some cast bullets for practice in a 44mag and 45/70 rifle. I mostly use charges of Uni. Clays (Unique burn rate apx) and have good resluts. The question I have comes from reading about wanting a powder to fill a case and still keep pressures low for good cast bullet performance, ie 45/70. The question is

Do you know anything about using slow burn rate powders in a case like 45/70 with cast bullets. I am thinking along the lines of the surplus mil powders such as

WC870 ( apx H870 burn rate)
and
WC872 ( slower then 870 )

I can get WC872 for $25 / 8 lbs locally so I was hopping to use it for low pressure practice loads.

What are your thoughts and years of life tell you about this idea ?

You're facing the classic dilemma of loading smokeless powder in a large-caliber, straight-wall, black-powder case.

A caseful of a faster powder puts entirely too much energy in there, and its burning raises pressures entirely too high, too fast.

A caseful of an appropriate slower powder can't burn to its best efficiency, because the large bore and bullet diameter lets the bullet move too soon, too fast for the powder to develop its full potential.

I do not know any good way to resolve this dilemma.

Ken,

I am not really intrested in burn efficieny, rather does it work, and it there any down side, such as wear on barrel, excessive residue in bore and so forth?

With the cost of the slow surplus powder I can do a lot of inefficient shooting. I am just looking for a cheap, safe and hopefully accurate fun, target load.

As a final note, 12g of Uni. Clays is not going to break any bank and a pound goes a long way, but with all that empty space in there it is very easy to miss a double charge.

Then I'd say 'go for it!" Pick. You'll have safe loads and may have to sweep a line of unburnt powder out of your barrel. You also may have to go to a hotter primer, and I'd definitely crimp the bullets with as heavy a crimp as the die provides.

As far as relative cost goes, don't compare the two powders' cost canister-to-canister or even pound-to-pound. The cost of each load is the true index of which powder is cheaper to shoot. Four times as much powder per charge, at half the cost per pound, is not economical. Figure and compare the costs per charge or per hundred charges.

Thanks Ken,

I will do the math and see what it really is. I do like the Idea that double charges will be nearly impossible.

I have a Lee factory crimp die so a full crimp in no trouble. Also I may just pick up some Fed 215 primers for good measure. I have the CCI 250 to start with. I will try them and see how it goes, before springing for some of the Fed 215's.

Will keep you posted as to results, soot and all.