9mm and Herco

[ohman11]

I did a search and still didn't come up with a answer. I have found several sites where they are using 6+ grains of herco in a 9mm luger. I was doing some testing and 6 almost fills the case. Hornady manual says 4.8 is max. Give me your thoughts on this.

 

[fecmech]

Alliant lists 6.5 grs of Herco for a 125 FMJ bullet in the 9MM, you did not mention a bullet weight.

 

[ohman11]

Sorry It is 125 lead round nose.

 

[Jim Watson]

The NRA showed 6 grains of Herco as a maximum load for a 125 gr 9mm, a good number of years ago. Nick Harvey's Manual shows 5.3 for a 125.

 

[rcmodel]

2002 Alliant guide says 6.2 grains gives 1,165 FPS @ 28,500 PSI with a 125 lead bullet.

rc

 

[ohman11]

Do you think 5.5 is a safe starting point for a 125 lead bullet?

 

[rcmodel]

If 6.2 is max, then a 10% reduction would be 5.6 grains.

I would not expect any problems with Herco at a full 6.2 load.
I would expect incomplete burning at 5.5 or 5.6.

rc

 

[zxcvbob]

Herco would be a perfect powder for 9mm and cast bullets, except it's too bulky. 7.5 grains will fill it to the top with no room for the bullet. 6.5 grains with a normal bullet seating depth will be compressed 25% or more. It's fluffy enough that might be OK, just be careful.

WSF is identical (from my little bit of testing in revolver cartridges) to Herco, except it measures easier and is much less bulky.

 

[rcmodel]

But, 7.5 and 6.5 are both over the max load listed by Alliant.

6.2 will compress & fit with no safety issues, or they wouldn't list it.

rc