375 Winchester

ruger357w · August 5, 2022, 05:25 AM

Wondering if it would be safe to use 38-55 brass in my marlin 375 Winchester? I have very little 375 brass for it. Have have run a few 30-30 case in it. Thanks for any information

**Mike Irwin** · August 5, 2022, 05:50 AM

Not loaded to .375 pressure levels it wouldn't be.

The .375 is beefier through the head and lower case walls than the .38-55.

Trying to run .38-55 brass to the same pressures as .375 could result in case separations or even case failures.

Starline sells .375 brass, but it's currently backordered.

Arthur Brown has it in stock, but it's made from .30-30 brass.

https://www.eabco.net/375-Winchester...0_p_13543.html

Were I you, I'd stick with using reformed .30-30 brass. It's beefier through the head dimensions than .38-55 brass.

ruger357w · August 5, 2022, 06:40 AM

Thank you. I'll stick with 30-30 reformed brass until 375 becomes available then.

ruger357w · August 5, 2022, 08:49 AM

I have one other question and probably dumb but it rather be safe. I happen to have way more 32 Winchester special new cases then I have of 30-30 so I'm thinking I can just blow them out to the 375. Please correct me if I'm wrong.

**Mike Irwin** · August 5, 2022, 11:34 AM

.32 Special would also be fine.

Now, I will add one caveat, but you should be OK...

Max pressure on both the .30-30 and the .32 Special is 42,000 PSI.

Max pressure on the .375 is 55,000 PSI.

Were I you, I'd keep my loads off top level just in case.

ruger357w · August 5, 2022, 01:12 PM

Ok. That's what I was think I would do. Thank you for the information.

dahermit · August 9, 2022, 08:01 PM

Quote:

Originally Posted by ruger357w

Wondering if it would be safe to use 38-55 brass in my marlin 375 Winchester? I have very little 375 brass for it. Have have run a few 30-30 case in it. Thanks for any information

As I remember, .38x55 brass is longer than .375, .32 Win.Spl, .30-30.
So, if you are trying to use .38x55 in a lever action, and you have .375 Win dies, it would have to be trimmed to be able to crimp in the bullet's crimping groove.

**Mike Irwin** · August 10, 2022, 07:35 AM

"As I remember, .38x55 brass is longer than .375, .32 Win.Spl, .30-30.
So, if you are trying to use .38x55 in a lever action, and you have .375 Win dies, it would have to be trimmed to be able to crimp in the bullet's crimping groove. "

.38-55 is longer than .375.

So are blown out .30-30 and .32 Special.

ALL have to be trimmed to proper length.

But that doesn't negate the fact that the .38-55 case isn't as strong through the head and lower case walls as any of the other rounds, so if .38-55 is repurposes to .375, loads need to be kept on the milder side.

August 5, 2022, 05:25 AM	#1
ruger357w Senior Member Join Date: May 13, 2012 Location: Maine Posts: 158	375 Winchester Wondering if it would be safe to use 38-55 brass in my marlin 375 Winchester? I have very little 375 brass for it. Have have run a few 30-30 case in it. Thanks for any information

August 5, 2022, 05:50 AM	#2
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,383	Not loaded to .375 pressure levels it wouldn't be. The .375 is beefier through the head and lower case walls than the .38-55. Trying to run .38-55 brass to the same pressures as .375 could result in case separations or even case failures. Starline sells .375 brass, but it's currently backordered. Arthur Brown has it in stock, but it's made from .30-30 brass. https://www.eabco.net/375-Winchester...0_p_13543.html Were I you, I'd stick with using reformed .30-30 brass. It's beefier through the head dimensions than .38-55 brass. __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.

August 5, 2022, 11:34 AM	#5
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,383	.32 Special would also be fine. Now, I will add one caveat, but you should be OK... Max pressure on both the .30-30 and the .32 Special is 42,000 PSI. Max pressure on the .375 is 55,000 PSI. Were I you, I'd keep my loads off top level just in case. __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.

August 10, 2022, 07:35 AM	#8
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,383	"As I remember, .38x55 brass is longer than .375, .32 Win.Spl, .30-30. So, if you are trying to use .38x55 in a lever action, and you have .375 Win dies, it would have to be trimmed to be able to crimp in the bullet's crimping groove. " .38-55 is longer than .375. So are blown out .30-30 and .32 Special. ALL have to be trimmed to proper length. But that doesn't negate the fact that the .38-55 case isn't as strong through the head and lower case walls as any of the other rounds, so if .38-55 is repurposes to .375, loads need to be kept on the milder side. __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.

August 5, 2022, 06:40 AM	#3
ruger357w Senior Member Join Date: May 13, 2012 Location: Maine Posts: 158	Thank you. I'll stick with 30-30 reformed brass until 375 becomes available then.

August 5, 2022, 08:49 AM	#4
ruger357w Senior Member Join Date: May 13, 2012 Location: Maine Posts: 158	I have one other question and probably dumb but it rather be safe. I happen to have way more 32 Winchester special new cases then I have of 30-30 so I'm thinking I can just blow them out to the 375. Please correct me if I'm wrong.

August 5, 2022, 01:12 PM	#6
ruger357w Senior Member Join Date: May 13, 2012 Location: Maine Posts: 158	Ok. That's what I was think I would do. Thank you for the information.