What type of powder in 7 mag Hornady Custom?

[JDB]

Recently bought a 7mm Mag to use for a 257 Wby build. Part of the deal was 18 rounds of new 7mm Hornady Custom 139gr. SST.

Any idea what kind of powder Hornady uses in their 7mm mag 139gr Hornady Customer loads? Each round had about 71.5-72gr of a spherical type powder.

I pulled the 7mm bullets & resized the the brass down to 257 wby. I would like to use that powder as my fireforming load.

 

[JDB]

Re: What type of powder in 7 mag Hornady Custom?

btt

 

[Squid284]

Re: What type of powder in 7 mag Hornady Custom?

Did the box say superformance? If so I would say superformance is probably the powder. They don't use it for the heavier bullets in 7RM but I think they use it up to 154gr SST.

 

[JDB]

Re: What type of powder in 7 mag Hornady Custom?

No, this was just the Hornady Custom. It wasnt Superformance