I tried WAP in .357 Mag: Don't!

Cheapo · January 7, 1999, 02:47 AM

I will not publish any charge weights, but here are the general results of some careful load testing. All was with 125-gr cast bullets.

Initial experiments were with a charge close to what Winchester recommends for 231. Winchester cases and a 9mm hard-cast gas check bullet that produces 2" groups from a SIG P226. Groups were good, velocities were mid-1100s, but some rounds had light recoil and report--as light as 148-gr wadcutter .38s.

Went to Oregon Trail bullets since the pointy 9mms sometimes backed out and hung up the cylinder despite being sized .358. Loaded 10 each of two charges .3 grains heavier than the original. Velocity spread was 220+ fps in the six-inch M28, but only 80 or so in a 4-inch M19. Cases fell out of the cylinders and the Win WSP primers showed less flattening than CCI +P .38s did. Accuracy was okay.

Went up another .3 gr each for two more loads. Similar results, but velocities were approaching what I wanted from the 6-inch. Spreads were still very erratic. I suspected sensitivity to powder position, despite about 65-75% loading density by volume. First shot in one string was high, next three low, and the last one (after re-setting the targe that blew over) was almost as high as the first. Still 200+FPS spread in the six-inch.

The next batch tended to disprove that theory, as elevating and depressing the muzzle before alternating shots didn't have a predictable effect. ES was lower in the six inch but still pretty broad. Cases again fell out of the chambers and had no primer pressure signs.

ES was acceptable in the 4-inch Mod 19, and accuracy continued to be good. But the cases stuck rather badly and primers showed some minor cratering.

End of experiment. Perhaps it was because the M-19 loads were in older Super-X cases instead of new Winchesters, but the weights of those two lots are almost identical (spreads overlap, but Remingtons *are* heavier).

I suspect that WAP just performs erratically in larger-capacity cases. The large ESs and clear LOW pressure signs on earlier loads seemed to indicate not enough powder to reliably reach operating pressures/temperatures. There was a clear correlation of low velocity with more rounded primer edges. But when boosting the charge weights up, the pressure and velocities never stabilized within proper limits.

Now I'm going to try some published loads using Power Pistol. It looks like it might be as versatile as Unique, as far as pistol & revolver loads go.

Cheapo.

wolfz · January 13, 1999, 11:44 AM

Cheapo
I've been experimenting around with WAP (I guess you are aware, Win. is discontinuing it) in .357 and 400Corbon (it is recommended by Corbon). I found that in the .357 I could get very consistent velocity results if between every shot I "shook" the gun to redistribute the powder in the cartridge to be fired next.It's been theorized in rec.guns that this may be why Win. is stopping production.

On the other hand, when the loads published by Corbon is used in the necked down .45 ACP case the case is 75%-90% filled, and combustion is very uniform. I consistently get 1400 fps with a spread of <25fps from a 5" barrel with 135g JHP.

I too am looking to change to P.P. or even Unique, for cost and commonality with my other calibers

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January 7, 1999, 02:47 AM	#1
Cheapo Senior Member Join Date: November 19, 1998 Posts: 986	I will not publish any charge weights, but here are the general results of some careful load testing. All was with 125-gr cast bullets. Initial experiments were with a charge close to what Winchester recommends for 231. Winchester cases and a 9mm hard-cast gas check bullet that produces 2" groups from a SIG P226. Groups were good, velocities were mid-1100s, but some rounds had light recoil and report--as light as 148-gr wadcutter .38s. Went to Oregon Trail bullets since the pointy 9mms sometimes backed out and hung up the cylinder despite being sized .358. Loaded 10 each of two charges .3 grains heavier than the original. Velocity spread was 220+ fps in the six-inch M28, but only 80 or so in a 4-inch M19. Cases fell out of the cylinders and the Win WSP primers showed less flattening than CCI +P .38s did. Accuracy was okay. Went up another .3 gr each for two more loads. Similar results, but velocities were approaching what I wanted from the 6-inch. Spreads were still very erratic. I suspected sensitivity to powder position, despite about 65-75% loading density by volume. First shot in one string was high, next three low, and the last one (after re-setting the targe that blew over) was almost as high as the first. Still 200+FPS spread in the six-inch. The next batch tended to disprove that theory, as elevating and depressing the muzzle before alternating shots didn't have a predictable effect. ES was lower in the six inch but still pretty broad. Cases again fell out of the chambers and had no primer pressure signs. ES was acceptable in the 4-inch Mod 19, and accuracy continued to be good. But the cases stuck rather badly and primers showed some minor cratering. End of experiment. Perhaps it was because the M-19 loads were in older Super-X cases instead of new Winchesters, but the weights of those two lots are almost identical (spreads overlap, but Remingtons are heavier). I suspect that WAP just performs erratically in larger-capacity cases. The large ESs and clear LOW pressure signs on earlier loads seemed to indicate not enough powder to reliably reach operating pressures/temperatures. There was a clear correlation of low velocity with more rounded primer edges. But when boosting the charge weights up, the pressure and velocities never stabilized within proper limits. Now I'm going to try some published loads using Power Pistol. It looks like it might be as versatile as Unique, as far as pistol & revolver loads go. Cheapo.

January 13, 1999, 11:44 AM	#2
wolfz Senior Member Join Date: October 13, 1998 Location: Chandler, Az, USA Posts: 125	Cheapo I've been experimenting around with WAP (I guess you are aware, Win. is discontinuing it) in .357 and 400Corbon (it is recommended by Corbon). I found that in the .357 I could get very consistent velocity results if between every shot I "shook" the gun to redistribute the powder in the cartridge to be fired next.It's been theorized in rec.guns that this may be why Win. is stopping production. On the other hand, when the loads published by Corbon is used in the necked down .45 ACP case the case is 75%-90% filled, and combustion is very uniform. I consistently get 1400 fps with a spread of <25fps from a 5" barrel with 135g JHP. I too am looking to change to P.P. or even Unique, for cost and commonality with my other calibers