Problem with some 357 magnum reloads

[Scope]

I had a problem with my Colt Python 357 mag and I thought I would get some calgunner opinions about it.

A few weeks ago my dad gave me some handmade reloads in 357 magnum which I tried to shoot in my Python. After almost every shot there was a lot of resistance to the cylinder rotating, and in some cases it wouldn't rotate out at all until I managed to wiggle the cylinder free and unload the particular cartridge. On the 8th shot I had to wrestle with it for a few minutes before I could even get the cylinder to rotate out and and unload the cartridge. I had enough and set my dads reloads aside. I then bought some factory ammo and ran it through the gun without any problems.

My dad included some reloading info:

140 Gr Hor. XTP-HP
12.1 Gr SR 4756
Mol = 1.6 (BK 1.598)
MV = 1150
win primers

The cases are nickel.

Does anybody have any idea what might be wrong? I don't think its a problem with the gun since it handled the factory loads just fine.

[sza]

Those loads are almost TWICE Hodgdon's maximum recommended charge weight!

For the 140gr XTP, Hodgdon lists a minimum charge of 5.3gr and a maximum of 7.3.

I would absolutely under no circumstances shoot any more of those rounds. If you can post photos of some of the fired cases we could probably identify why the gun was binding up, but IMO you're lucky you didn't blow the darned thing up.

[Two Shots]

Too hot, Was the primer flattening out?

[rue]

Sounds like the primers aren't seated far enough into the primer pocket. Not sure about the load data though. I had the same thing happen in my GP100 and it was the primers. Look at the breach face around the firing pin hole and it will be all scratched up from the primers rubbing it.
Compare the primer depths on the reloads with the factory ammo or just run your finger nail on the bottom of the case.

[Scope]

Those loads are almost TWICE Hodgdon's maximum recommended charge weight!

For the 140gr XTP, Hodgdon lists a minimum charge of 5.3gr and a maximum of 7.3.

I would absolutely under no circumstances shoot any more of those rounds. If you can post photos of some of the fired cases we could probably identify why the gun was binding up, but IMO you're lucky you didn't blow the darned thing up.

Agh! Holy crap you're right. Well, I'm definitely glad that didn't happen. I will look the gun over to see if its been damaged in any immediately obvious way, and I definitely will not shoot any more of those reloads.

I called my dad and he looked at some book that was 40 years old which gave different numbers, something like 7 to 9 Grs SR 4756. He swears that in the original book he used (he didn't have it available during the call) lit isted numbers like 12 - 13 Grs. Its probably an old book too. Have the propellants changed? Why is there such disparity in this data?

[Scope]

Too hot, Was the primer flattening out?

I am not sure how to tell, since the primers on the unfired shots look pretty flat to me. There is mechanical scraping along the fired primers and along the backs of fired casings.

[sza]

I called my dad and he looked at some book that was 40 years old which gave different numbers, something like 7 to 9 Grs SR 4756. He swears that in the original book he used (he didn't have it available during the call) lit isted numbers like 12 - 13 Grs. Its probably an old book too. Have the propellants changed? Why is there such disparity in this data?

Published load data has generally been decreasing over the years. Whether it's because of a more litigious society or a better understanding of internal ballistics is a matter of some debate.

It's certainly possible that SR 4756 has changed over the years too, but I've never personally used it so I can't say from first hand experience.

Edit: The data I gave you is from Hodgdon's website. None of the printed load books I have show any loads with SR 4756 in .357mag.

[ar15barrels]

I am not sure how to tell, since the primers on the unfired shots look pretty flat to me. There is mechanical scraping along the fired primers and along the backs of fired casings.

This is where the CASE extruded onto the breech face.
STOP shooting that ammo.
It's WAY too hot.

[-hanko]

Agh! Holy crap you're right.

I called my dad and he looked at some book that was 40 years old which gave different numbers, something like 7 to 9 Grs SR 4756. He swears that in the original book he used (he didn't have it available during the call) lit isted numbers like 12 - 13 Grs. Its probably an old book too. Have the propellants changed? Why is there such disparity in this data?

Powder charges have generally declined over time. Part of the reason may be more lawyers watching over reloading manuals. The major reason may be the difference in pressure testing a load...there are real differences between the older CUP standard and more modern piezoelectric testing.

Everybody else is correct with the "don't shot it no more" recommendation.

I'd strongly suggest you have a gunsmith check the Python for cylinder alignment; overloads can tweak the crane a little before you'd notice. AMHIK

-hanko