9mm bullets in a .357 shell case ?

fire@will

fire@will

Regular
Super GunNutz
Rating - 100%
40   0   0
Location
Oshawa
G'day gents.
Need to avail myself of the collected wisdom in this forum. I'm about to put some .357 cartridges together. I have a couple hundred 158 grain, plated .357/.38 bullets - and a couple thousand 125 grain, plated 9mm bullets. Is the .002" difference in diameter, enough to make using the 9mm bullets in a .357 case, a dumb idea ?
Thanks for your input. - F@W
 
I have used .357 bullets for 9mm (.355) and 9mm bullets for .357. If your bullets stay where you seat them there will be no issue, maybe poor accuracy but maybe not. Starting the bullets off with enough pressure to obturate the bullet into the rifling seems to help a lot.
 
They're smaller, so no safety issue (Even the other way around, .002" bigger, would likely be fine as long as you kept an eye out for pressure signs). If you're running a crimp die, they should stay put like B mentioned. Depending on the land diameter of your barrel, they might engage fine and be accurate, or they might not and be inaccurate or tumble. Only one way to find out.

Not the best idea anyone has ever had, but not a dumb idea I don't think.
 
How do you know those 125gr plated bullets are .355"? It is quite common to run .357" sized cast bullets in 9mm. The extra .002" makes absolutely no difference.
 
I Dont Care About You said:
How do you know those 125gr plated bullets are .355"? It is quite common to run .357" sized cast bullets in 9mm. The extra .002" makes absolutely no difference.
Click to expand...

The bullet profile is likely to cause more issues than anything else when talking .357/.38 bullets in 9x19. A lot of .357 bullets need to be seated very deeply to avoid jamming into the rifling. That's not a huge safety issue but can make clearing the gun a PITA if you don't accomodate it.

Keeping it on topic, a taper crimp may not provide enough tension due to springback but I have done well enough. Sometimes they would collapse in a lever gun so I just single fed them. Using/buying proper bullets saves time and effort.
 
Thank you Gentlemen. Appreciate your thoughts. I grabbed a small handful of each and checked them out on my dial caliper (again). There doesn't seem to be precise consistency between them. They're all between a c-hair over .355" and a c-hair under .358 - some "fat" 9mm and some "skinny" .357 . I'm not a terribly wonderful shot, so any minor discrepancies in accuracy, likely won't be noticed by me. I was more concerned if any "leakage" would get past the slightly smaller bullet and booger up my bore.
Thanks again - you guys are the best !
 
fire@will said:
Thank you Gentlemen. Appreciate your thoughts. I grabbed a small handful of each and checked them out on my dial caliper (again). There doesn't seem to be precise consistency between them. They're all between a c-hair over .355" and a c-hair under .358 - some "fat" 9mm and some "skinny" .357 . I'm not a terribly wonderful shot, so any minor discrepancies in accuracy, likely won't be noticed by me. I was more concerned if any "leakage" would get past the slightly smaller bullet and booger up my bore.
Thanks again - you guys are the best !
Click to expand...

It might end up being a little more than a "minor discrepancy in accuracy". Shoot at distance and check the target for keyholing (example below) after firing the .355's in your .357. Also, as has already been mentioned, just check the tension on the bullet after crimping to make sure it isn't going anywhere. I'd probably use a taper crimp for this situation, although you could probably get away with a light roll crimp.

P.S. Don't load hundreds of those .355 rounds without testing them first.

udhejm6w96351.jpg
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom