9mm cast bullets in a 357

[inline50]

Can you use 356. dia. cast bullets in a 38 / 357 if you stick with light loads for target practice. I would not think the .002 diameter difference would cause a problem. Has anyone tried this or is it dangerous?

[Gunslinger]

It's not dangerous... unless you are afraid of a little leading... because that is most likely what you'll get. Most .357 revolvers have a bore size of .357 or .358. Do you know the size of your barrel? If not you need to slug it, as size is crucial to casting. It's very easy to do, but if you do not know how use the search... there are a lot of threads on the subject.

The problem is that if the bullet does not seal the bore the powder gasses melt the sides of the bullets leaving lead smears in your barrel. This would happen with lighter loads as well as with hot loads.

[Echo]

Boolit diameter vs. groove diameter is the deciding factor - well, throw in chamber leade diameter as the most important measure on the gun. Whatever boolit is cast, whether for 9mm or .357 should be at the diameter of the chamber neck (I forget the correct name for the space in the chamber between the chamber and the front of the cylinder - CRS attack).
If the neck diameter is the same, or maybe a little larger than, the groove diameter, and if the boolits are the same size, or a smidge larger, then there should be no issues. I have had no luck whatsoever trying to shoot .355 or .356 boolits through my BH. They rattle down the bore, bouncing from one side to the other, and have a mind of their own once they leave the muzzle.

[1Shirt]

Better be thinking about a lot of leading unless you beagle your mold(s) and get the blts up around 358. Better yet, invest in a lee mold for 357/38s. You will have much less consternation, and a lot more satisfaction I think.
1shirt~:coffee:

[beagle]

Well now.....depends on the circumstances. I have an old 1958 vintage Colt Python that loves .356" bullets. But, under normal circumstances, these guys are right. You can shoot them but expect a whole lot of leading and not much accuracy.

An op"bump" them up to .358"./beagle

[mooman76]

Lee has a small 38 mould that works for 9mm also and drops a 105gr. SWC bullet. Nice plinker that shoot well.

[higgins]

I too have an older Colt revolver with a .355 groove diameter, so don't assume anything before you slug your barrel. I would suspect a newer revolver, particularly a non-Colt, would be closer the .356-.357. I haven't slugged the chamber mouths on my old Colt, so can't comment on that. It has been reasonably accurate with .358 bullets for about 40 years now, but before I load up another batch I'll slug the chamber mouths and possibly go to .356 or .357 bullets if they're not too loose in the chambers.

[2ndAmendmentNut]

I have a Ruger GP100 with chambers that measure just over 357. I have shot cast 9mm boolits sized at 355 and 356 with out any negative effects, good accuracy, no leading. I use Lee’s 125gr RN boolit mold which drops a boolit with a flat base, my alloy is soft and air cooled, and my velocity is low. Hope you have the same success.

-2ndAN

[AJG]

I have an Problem (I am located in Southamerica): I got my RCBS taper crimp 3 die set today and have on Hand my Heritage (Pietta) Rough Rider in 357 mag 5.5" blued but locally THERE ARE NO 357/38SPL BULLETS availlable.
I am scavenging powder and lead from shotshells for reloading 9mm, 38 spl and 357 Magnum. Unfortunatelly I can not get 38 spl bullets nor did my lead casting mold arrive yet.

I am set up for reloading 357 mag/38 spl but have no bullets. However I have 200 9mm Winchester 115 grain FMJ hollow base bullets.

Data:
a) Factory Winchester 110 grain 357 mag hollow Point semi jaket measures rigth at the case mouth on the bullet 0.350" diameter.
b) 9mm Factory PMC 115 grain FMJ measures rigth at case mouth on bullet 0.356" diameter.
c) Winchester bullet 9mm FMJ (reloading component) measures Diameter 0.355" Diameter.
d) 357 mag Revolver cylinder hole (end where it meets the forcing cone) measures 0.353" Diameter.
e) 357 mag Revolver Barrel measures 0.345" Diameter approximatelly (it varies according if I hit rifling) at muzzle end (crown).

I bet I can just use the 9mm Winchester reloading components for the 357 mag as well to reload.

Can I use the 9mm bullets to load them in the 357 mag Rough Rider without damaging the gun? Please any experiences!!

[GWM]

Can I use the 9mm bullets to load them in the 357 mag Rough Rider without damaging the gun?

There will be no damage to the gun from the bullets.

[Scharfschuetze]

I use the 147 grain 9mm boolit sized to .358" in my 38s and 357 Magnums with good results. As it is sans crimping groove, I slightly roll crimp over the ojive for a good tight hold on the boolit in revolver charge holes. It's very accurate and if a fellow were limited to just one mold for both the 38/357 and 9mm/38 Super handguns, this would be a good choice.

http://www.midwayusa.com/product/743639/lyman-4-cavity-bullet-mold-356637-9mm-356-diameter-147-grain-flat-nose-bevel-base

If your 357 Magnum is an older Colt DA revolver, .356" will probably be just fine. If it is a newer Trooper or an S&W, you (as noted by several above) are best off with .358" boolits.

I use .358" diameter for both the revolvers and my 9mm semi-autos. Makes it easy to stockpile and load as needed.

[mdi]

Sorta on subject; I use the same bullet in 3, 9mms, 2, 38s, and 1, 357 Magnum, just run it through a different sizer, Lee 125 gr. RNFP. 357 Mag. gets bullets sized to a bit over .358", 38 Specials get .357" and two of the 9mms get a .357" and one gets a .358" (mebbe .359"). It's all about bullet diameter, cylinder throats, and groove diameter...

The only "drawback" would be no crimp groove for a bullet designed for a semi-auto, but that's why they make taper crimp dies...

[GhostHawk]

Just this week I have been loading .357 bullets unsized in 9mm cases.
I have 2 guns that like them bigger than .356. These came out of a Lee .358 124 gr 6 cavity mold and they show .360 on my cheap HF digital.

But they loaded with no issues and both guns love them. So I loaded up 400 to get restocked.

Matters less with Jacketed, cast for good accuracy helps to be a couple thousandths big.

[taco650]

Softer lead bullets will bump up in base size when fired and provide bore seal which reduces or eliminates leading.

[farmerjim]

Powder coat them. 1 to 2 thousands per coat.

[Walter Laich]

paper patching is a cheap way to go. Takes a bit of time but if you're limited on what molds you can get you can try this method.
Won't hurt anything for sure
see section on paper patching for smokeless to learn more