MO Bullet 125 gr. How fast can I go in 357 Mag?

[Rule3]

I finally picked up a Marlin 357 carbine (been searching for a long time Now that they are closing I get one)

Anyway, I have several boxes of MO bullets 158 gr LSW which I use in my revolvers but this carbine will not feed them. I also have the 125 gr RNFP but they are Cowboy loads and are only 12 hardness.

I am using HP 38 and if I load them at max 5.5 grs do you think i will have a leading problem?

I did the Cups calculation of 18,800 cups/1279.8=BHN of 14.
This is from the Lee tables and shows 1185 fps(Also the Hodgdon online data) 10" barrel

The only harder bullets I see online for MO bullets is the 180 gr Striker but i really do not need or want that heavy of a bullet in .357.

 

[joneb]

I finally picked up a Marlin 357 carbine

Does it have the micro groove rifling ?

I also have the 125 gr RNFP but they are Cowboy loads and are only 12 hardness.

Are these .358 or .357 diameter ?

 

[Rule3]

No to the micro groove. My 22 LR has that. The rifle(carbine) 1894c has regular Ballard Rifling(6 grooves, 1:16 twist) and the MO bullets are .358 diam.

125gr RNFP , 12 BHN

 

[joneb]

The lightest lead bullet I've loaded and shot in a .357 mag carbine is 158gr LRNFP cast, at 12-14 BHN with Trail Boss and Unique, so I'm not much help to you.
As for velocity I wouldn't go much over 1,000fps. I think the bullet fit to your barrel will be a factor as well as the powder and charge. Have you slugged the barrel to determine the groove diameter ?

 

[MissouriBullet]

I finally picked up a Marlin 357 carbine (been searching for a long time Now that they are closing I get one)

Anyway, I have several boxes of MO bullets 158 gr LSW which I use in my revolvers but this carbine will not feed them. I also have the 125 gr RNFP but they are Cowboy loads and are only 12 hardness.

I am using HP 38 and if I load them at max 5.5 grs do you think i will have a leading problem?

I did the Cups calculation of 18,800 cups/1279.8=BHN of 14.
This is from the Lee tables and shows 1185 fps(Also the Hodgdon online data) 10" barrel

The only harder bullets I see online for MO bullets is the 180 gr Striker but i really do not need or want that heavy of a bullet in .357.

We have the #1 Ranger, which is the 18 BHN version of the 158 grain RNFP, intended for higher rifle velocities. Or, if you want the 125 TCFP in harder alloy, we can do that, too.

 

[Rule3]

We have the #1 Ranger, which is the 18 BHN version of the 158 grain RNFP, intended for higher rifle velocities. Or, if you want the 125 TCFP in harder alloy, we can do that, too.

DUH! I looked at the web site on all the Pistol bullets and never thought to look at Rifle.

Yes, the #1 Ranger 158gr is what I was looking for! All I shoot from my 357 revolvers is your 158 gr LSWC so the 158 RN would be perfect!

Thanks