04-04-2005, 06:55 PM
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Join Date: Dec 2002
Location: Jefferson Parish (via N.O.)
Posts: 9,035
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WHile I don't have a #2 Roller, do load for a Marlin 27S as wella s a S&W and a Colt 32-20. Do try to stay UNDER the max. pressure level even though these three are rated for smokeless...Lyman #48 losts loads up to 16K, but with the notation that they are NOT for Blcak Powder guns.
The starting loads, and in some cases starting loads plus 10%, have prooven to be have about the same effect on a case as full black powder loadings. IS some debate about the difference in 12K peak black powder pressure and 12K peak smokeless pressure having the same stress effect on an action.
OFten, in teh Marlin, will use black powder...thight here is that NOTHING you do to a 32-20 is going to put it in the deer rifle class, so all that strain seems to be for no real gain.
For what it is worth, the slow powders burn pretty dirty at these low pressures...leavoing enough fo thenmselves behind to be a problem. the fast powders are clean, but do limit velocity in that case at these pressures. The middle range of powders (Unique area on the burning chart)a seem to be the better compromise.
Will say taht the slower powders do better in a rifle than they do in a handgun. On a guess, the rifle's short jump to rifling gives better combustion due to early resistance...engravement is a pressure increaser. IN revovlers, there is that long smoothbore jump before rifling engravment.
Unique works with that bullet...4.2gr. seems to duplicate BP pressure pretty cloelsy, but to be honest...BP is faster.
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