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Old November 21, 2007, 01:46 PM   #5
Unclenick
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Join Date: March 4, 2005
Location: Ohio
Posts: 21,057
Hate to disagree, but I think those are too slow to be safe for the lightest bullets. The secondary pressure spike hazard becomes a real concern.

You can see the measured secondary pressure spikes repeated through several rounds of .223 firing a 40 grain bullet with AA2320 in the last illustration at the bottom of this page. The load combination appears in loading manuals. In this instance the spike is not above proof pressures, so it won't likely burst the gun, even if it adds wear. Spikes in other combinations have, however, been measured that exceed 120,000 PSI in some instances. That's what gets into muzzle bursting territory.

At 125 grains in .30 caliber, I would look at IMR3031. Its better burning efficiency will add a couple hundred fps to what you can get out of two slower powders, anyway. 4831 and 4350 run ballistic efficiencies of around 23% with that bullet. 3031 gets to 29% BE in a full load, which is what Hatcher liked for the .30-06.
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