.357 Mag for 30" Barrel

[ZigZagZeke]

I have a Remington #1 rolling block sporter with a 30" barrel that has had the barrel lined with a .357 caliber liner and has been chambered for .357 Mag. Firing factory Magtech 158 gr. SPs in it I get 1780 fps MV. I have tried some of the 180 gr premium factory loads and found that I am slightly flattening the primers. I hadn't planned on getting back into reloading, but I'm concerned about possible high pressures using fast burning factory pistol loads in a 30" barrel. I want to try some hand loads using a slower burning rifle powder and see what kind of velocities and pressures I get. Hand loads would also let me use some pointed bullets instead of the flat nosed or hollow points that are made for pistols. Anybody got any experience with this kind of situation?

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[Greenbug]

There are several loading manuals that list data for the 357 Magnum in rifle/carbine length barrels. Looking at the Hornady 7th edition it lists Alliant 2400 powder as a good perfomer for the 180 grain bullet. The Speer #14 manual has a load using Hodgdon Lil' Gun with 170 grain Gold Dots @ 1684 FPS out of an 18" test barrel. I think you might have some pressure concerns using slow burning rifle powder in this cartridge, I think you would be more looking for faster burning rifle powders (relatively speaking). Maybe check into Reloader 7, Accurate 1680, or Hodgdon Lil' Gun like listed above.

 

[deadshot2]

You might also consider the brand of primers you are using. In my rifle primers I've quit using Winchester primers. Even on moderate loads they look like they were poured into the primer pocket after firing. Only a small "line" around the perimeter. Change to CCI's or Wolf and the primers hardly loose any of the radius on the edge with similar loads. Some primer material is just plain softer than others and doesn't really give a good reading on pressure. Other factors like case head expansion, ease of extraction, and "stretch marks" on he case itself are better indicators in my opinion.

 

[ZigZagZeke]

You might also consider the brand of primers you are using. In my rifle primers I've quit using Winchester primers. Even on moderate loads they look like they were poured into the primer pocket after firing. Only a small "line" around the perimeter. Change to CCI's or Wolf and the primers hardly loose any of the radius on the edge with similar loads. Some primer material is just plain softer than others and doesn't really give a good reading on pressure. Other factors like case head expansion, ease of extraction, and "stretch marks" on he case itself are better indicators in my opinion.

The 180 gr factory cartridges I've tried are American Eagle. These are the ones where the primer appears to have been flattened somewhat, but not severely. They are not falling out of the pocket or anything like that. I have had a case or two that didn't extract easily, but only a couple out of maybe 50. I've stayed away from those cartridges since trying them for the first time and I've had no problems with the 158 gr Magtech. The primers look fine and no extraction problems. Could it be soft brass in the American Eagle casings?

I used to load 4895 in my .270 and .30-06 casings, and 4350 in my .243 and .222 casings. Seems like 4350 might be a good choice for .357 Mag in a 30" barrel? Is optimum powder burning speed determined more by bullet weight or case size/barrel length?

 

[ZigZagZeke]

There are several loading manuals that list data for the 357 Magnum in rifle/carbine length barrels. Looking at the Hornady 7th edition it lists Alliant 2400 powder as a good perfomer for the 180 grain bullet. The Speer #14 manual has a load using Hodgdon Lil' Gun with 170 grain Gold Dots @ 1684 FPS out of an 18" test barrel. I think you might have some pressure concerns using slow burning rifle powder in this cartridge, I think you would be more looking for faster burning rifle powders (relatively speaking). Maybe check into Reloader 7, Accurate 1680, or Hodgdon Lil' Gun like listed above.

Thanks! If I decide it's time to get back into hand loading I'll check those out.