Need .357 mag data with HS-6 & 158gr FMJ RNFP

[Bullseye25]

I can't find any data for this exact combo anywhere!!!

HS-6 is the slowest burning powder I have on my shelf, figured it'd be the best of what I have to load a medium+ .357 load.

Can't find any data for this powder and a 158gr FMJ RNFP with cannelure.

If anyone has experience or has published data on this particular load, any and all info would be appreciated.

Thanks.

 

[rcmodel]

Just use Hodgdons data for the 158 grain XTP.
Start = 8.0.
MAX = 9.5.
Start at the Start load and work up to best accuracy in your gun.

The XTP hollow-point is a longer bullet then the RNFP you have, so the listed load range should be safe.

Correct OAL is seated to the crimp cannulure.

rc

 

[Bullseye25]

Great, I'll start there. I've seen a lot of debate over the need for magnum primers with .357 and HS-6. Are magnum primers necessary with this powder?

 

[rcmodel]

No, Yes, Maybe??

As you noted, there is differing opinions on that.

Hodgdon, who should know, lists it with standard primers in .38 Spl & .38 Spl +p.
But list Mag primers in .357.

I believe that is because most of the slower ball powders like H-110 and W-296 do require Mag primers, and they are all lumped together with HS-6 in the .357 Mag data.

rc

 

[USSR]

Bullseye25,

Archangel is the resident HS-6 devotee, and he recommends a magnum primer to ignite HS-6. Perhaps he will chime in?

Don

 

[ArchAngelCD]

Bullseye25,

Archangel is the resident HS-6 devotee, and he recommends a magnum primer to ignite HS-6. Perhaps he will chime in?

Don

Many reloaders claim they use HS-6 without magnum primer and have no problems. Then you get the reloaders who don't use magnum primers but badmouth the results they get complaining HS-6 is no good. I have found using a magnum primer with HS-6 improved the performance greatly. I get a more complete powder burn, more consistent velocities and single digit SD numbers. They cost no more than standard primers so why not use them? (especially in colder weather)