357 reloading with HS-6. Magnum Primers or No?

torquimata

Been reading mixed opinions on the web about using magnum small pistol primers and Hodgdon HS 6 powder for 357's. Used HS6 for some 45 Colts with standard large pistol primers and it was awful, lots of unburnt powder, will not do that again, will use magnums in that caliber from now on. However, was wondering with smaller 357 case if I should use magnums or will I have to worry about pressure problems. Any advice is always appreciated and thank you!

bambambam

I use small pistol for HS-6, W296, & Titegroup in my GP-100 .357 mag rounds.

Mobuck

Actually, it might burn cleaner at a higher pressure. Long time since I loaded with HS6 but IIRC it didn't do well with light loads.

bpost

Mobuck is correct. The unburned powder can be from light loads. Low pressures can cause erratic ignition and unburned powder even when using magnum primers.

Rocky Raab

Using magnum primers to correct poor burning is a mistake. No ballistics lab would recommend it.

The higher initial pressure can unseat the bullet, which has the effect of increasing case volume. That in turn causes the powder to burn LESS efficiently for a brief moment, and pressure actually drops. Then the bullet encounters the lands and slows. Pressure rises again, creating a "double hump" pressure curve which can be very erratic. Overall velocity can be less, muzzle velocity can have a wide spread, accuracy is liable to be worse. And in the worst case, you can experience a hangfire or squib, especially in a revolver if the bullet clears the cylinder gap as the pressure is first falling.

Increase the charge, load a heavier bullet, or change powder. But do not switch to a magnum primer.

torquimata

Thank you for the great advice. I will try regular small pistol primers and loads on the heavier side of the HS-6 powder/bullet
range!