Herco load data for .45 colt?

[sixgunnin]

What is a max load of Alliant Herco in .45 Colt with a 255 gr RNFP? I can find Herco load data for 250 grain cast bullets but nothing on the 255 grainers.

Is 9 grains about right? What would you guys recommend for a safe but hot load?

I will be using them in a 4.62'' New Vaquero and possibly a 16'' levergun

 

[MSD Mike]

Should be in the ballpark. Alliant shows 9.5 grains of Herco for a 250 grain bullet and five grains of bullet weight wont make a huge difference. In the spirit of safety I would back off to 8.0 grains and work up in case your 255 seats a bit deeper than the 250 grain bullet. Never know how your gun will act.
For example, I have a Ruger Blackhawk in 45 Colt (5.5'' Barrel) that shoots 250 Grain LSWC 950FPS with 8 grains of Unique. Considerably faster than the manuals say it should. Anyway, I think you will find 9.0 Grains of Herco is fine but it is always prudent to back off and work up. Worst that happens that way is you spend more time shooting.

Mike

 

[black mamba]

It depends entirely on the gun you're using. In an old Colt Peacemaker, I'd stick with 9 grains. In a more modern gun like the S&W Model 25 you could easily go up to 10 grains, and in a large framed Ruger even more. In the smaller of the two Vaqueros I'd feel safe with up to 10 grains, but start lower and see if you get the accuracy you are looking for.

 

[GeauxTide]

In my Bisley Blackhawk

I've run 10gr of Unique under 280 SWC for 1057fps. That's a 20k PSI load and cases fall out of the cylinder. The lighter weight of the New Model, grip frame, and shorter barrel will dictate more about what you can shoot. My first 45 Ruger was a 4.6, and I didn't like it. Sent it back to Ruger for a 7.5.

 

[sixgunnin]

OK so I have worked up to 9.5 grains of Herco behind a 255 grain RNFP, the nickel plated cases fall right out. So I am wondering if that means I have a safe load?
How much velocity would you estimate I am achieving with that load?
I am happy with the power I am getting, but what about the long term wear and tear? Would you guys call that a hot load that I don't want to use much? I would like my new vaquero to last a long time so I don't want to use any load that is abusive.

Thanks

 

[black mamba]

Should be around 950 fps, give or take, and completely safe.

 

[sixgunnin]

This morning I borrowed a chronograph and they clocked in at 1030 fps! Will my new vaquero last forever shooting a steady diet of these? Or is it a little on the hot side?

 

[Real Gun]

For longevity of the gun, I would extrapolate that 9.0 max w/250 gr down to 8.5 w/255 gr. 45 Colt at over 1000 fps with a 255 grain bullet is heavy duty for that gun, but it should be fine. I don't know that it was designed for that long term though.

What you should do though is eventually branch out to other powders, for which you could find more load data.

 

[black mamba]

You must have pretty tight bore and/or chambers to be getting 1030 fps with that load. You get right at 50 fps for each ½ grain with Herco, so backing down to 9.0 should still give you around 980 fps, which is plenty.