Power Pistol and cast bullets...

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rnovi

New member
Ok, I swear I read a thread on this but dang if I can find it.

I'm loading .357 and I have a can of PPistol in the cabinet. I also have a lot of lead 158 gr. tcfp bullets (hard cast, rated to 1600fps). Burn rate of PP is similar to Unique but not the same...thinking of test loading from 5.0gr to 7.0 gr and seeing what works...

Anyways, the question is: How is PP with hardcast bullets? I think I read that PP is a "hotter" powder and may increase leading. Any confirmation here?
 
H

HSMITH

New member
I have used it with cast bullets. Works fine, might be a little more prone to leading than Unique and smokes a tad more but I didn't have any problems with it.
 
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Yuriens

New member
I feel leading is more a function of the speed you drive a bullet at than the powder used to push it. Go over 1000 fps and expect more leading.

Mike
 
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Leftoverdj

New member
I feel leading is more a function of the speed you drive a bullet at than the powder used to push it. Go over 1000 fps and expect more leading.
Click to expand...

It ain't. I drive cast up to 2400 fps pretty regularly without leading. Primary cause of leading is undersized bullets. Secondary cause is pressure mismatched to the hardness of the bullet. Third cause is poor lube.

Too light a charge under a hard cast bullet will cause leading as surely as too heavy a charge under a soft bullet will.
 
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rnovi

New member
Heh, and I always thought fire = fire temps! I never considered temperature ranges on powder vs. pressure ranges...

Too much for my little brain to handle!

Incidentally, I tested PP on the plated bullets in 9mm at 5.0, 5.3, and 5.5 grains. 5.0 cycled flawlessly and felt about "normal". 5.5gr was definitely on the hot side of things based on the muzzle flash and report (as well as the comments of a Master-class IPSC shooter I know).

Next step, chrono time at 5.0 gr to see what I am getting. I'm betting that 4.8 is closer to a minimum load.

I will test a similar load in .38 spec first and will chrono that up as well.

Leading doesn't really seem to be any problem with my guns at any velocity...until I hit around 800 rounds where accuracy really drops off and I start keyholing 12" groups at 21 feet...

Kind of a shocker when one expects nice, tight, 1" groups...
 
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Yuriens

New member
"It ain't. I drive cast up to 2400 fps pretty regularly without leading. Primary cause of leading is undersized bullets. Secondary cause is pressure mismatched to the hardness of the bullet. Third cause is poor lube."


For me it is. I find that Power pistol is no different than unique as far as leading in concerned. If I push my bullets at 1300 fps I get more leading than if i push them at 900. Hence my statement that velocity is more important than powder type for leading.

Now maybe I lead more at 1300fps because my bullets are undersize, out of round, too soft, crappy, etc..... I don't know. But I think the leading difference between 2 similar powders is negligable compared to velocity.

Mike
 
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Unclenick

Staff
If you want to test the effect of powder burn temperature on cast bullets, just sharpen a case and cut some 1/16" low density polyethylene wads from a sheet of the plastic. It virtually stops all traces of revolver leading when the powder flame doesn't lick the bullet base any more. These let you shoot soft bullets faster without leading. The LDPE melts slightly and helps lube the next round. NECO sells these as P-wads, but you can make your own. A sheet of plastic doesn't cost much.

Keep in mind that Elmer Keith developed the .44 magnum shooting plain base bullets cast of 20:5 Pb:Sn; about Brinell Hardness Number 11. He shot them at 1300 fps second or so, and didn't have serious problems with it. Lead can be made to go faster than you think when you lube it right and make sure it fits.

Two caveats on cast bullets in revolvers: The chamber throats need to match and the barrel must be fairly straight. Some guns come with chamber throats actually tighter than the barrel groove diameter, and these will never shoot cast bullets well until they get their cylinders reamed.

Make sure the revolver has no barrel constriction where the barrel is threaded into the frame. This makes the rear of the barrel tighter than the rest of it, causing the same problem tight chambers do. Namely, sizing the bullet down so gas can bypass and cut it and splatter the lead as it goes loosely down the rest of the tube. These barrels were common 20 years ago and are most likely to be found in guns over 10 years old. Nonetheless, you will run into a few new ones today if you start slugging barrels.

Nick
 
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