.380 on a 357

Lackwell · July 16, 2009, 07:10 PM

I have just gotten some old ammo (1964 date of assembly)
It is a .380 95 gr RN bullet loaded on a 357 Mag case with 13gr
of H110 powder with what I think is a small pistol mag primer.
Would you shoot this or would you advise to pull it. Have any of
you done this bullet combo before. The .380 is 355 diameter and
it should shoot but how accurate would it be?

Randy 1911 · July 16, 2009, 07:17 PM

Years ago I shot some 9mm bullets loaded in a 38 Spl. case. They shot, but the accuracy was poor. These bullets were .002 undersized for the .357 bore.

SL1 · July 16, 2009, 09:03 PM

Years ago I shot some 90 grain 9mm bullets from .357 Magnum cases with full-power loads. I don't remember the powder or charge weight right now, but could probably still find it if that becomes important. The accuracy was surprizingly good. I think that the high pressure of the load I used bumped the bullets up to cylinder throat and bore diameter, producing the good accuracy.

In that regard, I suspect that 13 grains of H-110 under a 95 grain bullet is going to be more than 3% under maximum, and therefore not necessarily going to ignite well and make high pressure consistently. I wonder why somebody would choose that load for that bullet.

SL1

**Unclenick** · July 17, 2009, 09:38 AM

Agree, that's not necessarily a safe load from the standpoint of getting bullets stuck in the bore. Experimenter's cook up. I would pull the bullets and, if you want to try shooting them, set the H110 aside for something more conventional and then use Bullseye or 231 or some other target load powder to make target loads with the bulelts. If you just have to see how fast you can make them go, I would be looking at 2400 or some such powder to work the loads up with.

RidgwayCO · July 17, 2009, 10:12 AM

My suggestion is to pull them. QuickLOAD predicts a pressure of only 7600 psi, and only 32% of the powder burns before the bullet leaves a 4" barrel. Winchester recommends only a 3% maximum reduction with 296 (the same powder as H110), and your 13.0gr load is way less than 3%.

Russ5924 · July 17, 2009, 12:23 PM

Take them apart save the cases and junk the rest. Are you really sure it's H110 if not get rid of it

July 16, 2009, 07:10 PM	#1
Lackwell Junior Member Join Date: March 27, 2009 Posts: 4	.380 on a 357 I have just gotten some old ammo (1964 date of assembly) It is a .380 95 gr RN bullet loaded on a 357 Mag case with 13gr of H110 powder with what I think is a small pistol mag primer. Would you shoot this or would you advise to pull it. Have any of you done this bullet combo before. The .380 is 355 diameter and it should shoot but how accurate would it be?

July 17, 2009, 09:38 AM	#4
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,738	Agree, that's not necessarily a safe load from the standpoint of getting bullets stuck in the bore. Experimenter's cook up. I would pull the bullets and, if you want to try shooting them, set the H110 aside for something more conventional and then use Bullseye or 231 or some other target load powder to make target loads with the bulelts. If you just have to see how fast you can make them go, I would be looking at 2400 or some such powder to work the loads up with. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

July 16, 2009, 07:17 PM	#2
Randy 1911 Senior Member Join Date: May 7, 2009 Location: Western Arkansas Posts: 273	Years ago I shot some 9mm bullets loaded in a 38 Spl. case. They shot, but the accuracy was poor. These bullets were .002 undersized for the .357 bore.

July 16, 2009, 09:03 PM	#3
SL1 Senior Member Join Date: November 8, 2007 Posts: 2,001	Years ago I shot some 90 grain 9mm bullets from .357 Magnum cases with full-power loads. I don't remember the powder or charge weight right now, but could probably still find it if that becomes important. The accuracy was surprizingly good. I think that the high pressure of the load I used bumped the bullets up to cylinder throat and bore diameter, producing the good accuracy. In that regard, I suspect that 13 grains of H-110 under a 95 grain bullet is going to be more than 3% under maximum, and therefore not necessarily going to ignite well and make high pressure consistently. I wonder why somebody would choose that load for that bullet. SL1

July 17, 2009, 10:12 AM	#5
RidgwayCO Senior Member Join Date: March 22, 2008 Location: Western Colorado Posts: 244	My suggestion is to pull them. QuickLOAD predicts a pressure of only 7600 psi, and only 32% of the powder burns before the bullet leaves a 4" barrel. Winchester recommends only a 3% maximum reduction with 296 (the same powder as H110), and your 13.0gr load is way less than 3%.

July 17, 2009, 12:23 PM	#6
Russ5924 Senior Member Join Date: February 18, 2005 Posts: 1,874	Take them apart save the cases and junk the rest. Are you really sure it's H110 if not get rid of it