Resizing primed and crimped brass in .357 magnum

AL45 · July 8, 2023, 05:07 PM

I reloaded some .357 magnum rounds using 158 grain jacketed with IMR 4227. These were accurate but also very dirty. I've got about 40 rounds left and was thinking of pulling, resizing and re flaring the cases and using a different powder. Is there any problem with this as long as I remove the decapping pin?

mehavey · July 8, 2023, 06:54 PM

Quote:

...any problem with this as long as I remove the decapping pin?

Nope.
Press on....

**44 AMP** · July 8, 2023, 06:56 PM

why do you think you need to resize the brass??

Pulling the bullets (done right) doesn't expand the case. Its not like firing them.

The bullet will "pull through" the crimp, "straightening" it out, so you will need to use the expander to re-flare the case mouth enough to seat a new bullet or reseat the original bullets, then recrimp as desired.

IMR 4227 is usable but not the best performing powder for the .357, max charge weights are about the same as 2400 powder but 2400 delivers higher velocity, about 100fps or so, usually.

AL45 · July 8, 2023, 07:53 PM

44 amp, I wasn't sure how well the crimp would straighten out by just pulling the bullet. If I can skip resizing, so much the better. I was given 2 lbs of IMR 4227 and am trying it out in different calibers. It has worked fine in.45 Colt, .454 casull and a reduced.308 load. Not so good in the .357. Lesson learned. Thanks

**44 AMP** · July 8, 2023, 10:39 PM

Since you are going to run the expander plug into the case to create a new case mouth flare, anyway, that will take care of any remaining crimp in the brass.

Since there was no firing to expand the case, the "neck" will be the same as it was and the same as it will be after you use the expander on it, again. Bullet seating should be the same, crimp the same, etc.

IMR 4227 is a fine powder for some things, does pretty well in large .44 and .45 cal cases, its too slow for shorter or smaller cases. Manages tolerably in the .357 there are a couple loads for it in .38 SPL but its not at its best there.

Not suitable for .45acp or 9mm or anything in that case capacity range, its just a tad too slow for efficiency.

Often (not ALWAYS but often) a slower powder burning "dirty" means incomplete/inefficient combustion. SOMETIMES, the cure is simply working up to a heavier load with that powder. Sometimes, its not, and going to a different powder will be necessary for both power and (relatively) clean burning.

July 8, 2023, 05:07 PM	#1
AL45 Senior Member Join Date: December 12, 2012 Posts: 766	Resizing primed and crimped brass in .357 magnum I reloaded some .357 magnum rounds using 158 grain jacketed with IMR 4227. These were accurate but also very dirty. I've got about 40 rounds left and was thinking of pulling, resizing and re flaring the cases and using a different powder. Is there any problem with this as long as I remove the decapping pin?

July 8, 2023, 06:56 PM	#3
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,932	why do you think you need to resize the brass?? Pulling the bullets (done right) doesn't expand the case. Its not like firing them. The bullet will "pull through" the crimp, "straightening" it out, so you will need to use the expander to re-flare the case mouth enough to seat a new bullet or reseat the original bullets, then recrimp as desired. IMR 4227 is usable but not the best performing powder for the .357, max charge weights are about the same as 2400 powder but 2400 delivers higher velocity, about 100fps or so, usually. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

July 8, 2023, 10:39 PM	#5
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,932	Since you are going to run the expander plug into the case to create a new case mouth flare, anyway, that will take care of any remaining crimp in the brass. Since there was no firing to expand the case, the "neck" will be the same as it was and the same as it will be after you use the expander on it, again. Bullet seating should be the same, crimp the same, etc. IMR 4227 is a fine powder for some things, does pretty well in large .44 and .45 cal cases, its too slow for shorter or smaller cases. Manages tolerably in the .357 there are a couple loads for it in .38 SPL but its not at its best there. Not suitable for .45acp or 9mm or anything in that case capacity range, its just a tad too slow for efficiency. Often (not ALWAYS but often) a slower powder burning "dirty" means incomplete/inefficient combustion. SOMETIMES, the cure is simply working up to a heavier load with that powder. Sometimes, its not, and going to a different powder will be necessary for both power and (relatively) clean burning. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

July 8, 2023, 07:53 PM	#4
AL45 Senior Member Join Date: December 12, 2012 Posts: 766	44 amp, I wasn't sure how well the crimp would straighten out by just pulling the bullet. If I can skip resizing, so much the better. I was given 2 lbs of IMR 4227 and am trying it out in different calibers. It has worked fine in.45 Colt, .454 casull and a reduced.308 load. Not so good in the .357. Lesson learned. Thanks