Maybe I went to the wrong forum first in the handrifle section. My question is what would be a good load to make use of a 12" barrel with a cast 250 gr pentagon HP? It may get used as backup in a new Vaquero. Just for finish shots. Wish I had a hunting 45 LC or 454 in a 9" SRH but only a 44 SRH right now. So it will be a Vaquero for now.
TIA Packy

If this is the new smaller framed Vaquero, it's not rated for +P loads like the old Vaquero.

I have a Contender carbine barrel in 45 Colt. I load 300 to 335 gr hard cast over a max charge of AA#9.

I can also shoot that load out of my Anaconda, but I wouldn't shoot it out of an new Vaquero.

As Slim said make sure what Vaquero you have first. I have a New Model Blackhawk and 14" Encore barrel in 45 Colt and both shoot very well with the 270SAA grain bullet and a very stiff charge of Lil'Gun or H110.

Steve.........

Yes you can make the 45 Colt into a super magnum with H110; Safely. And the old Vaquero with the big cylinder too.
It will get your attention for sure,
But you must experience the real 45 Colt as it was intended; 35 grains of 3fg black powder. Whole different experience. Every 45 owner should do that just to see what is was like in 1880. Ok, except for the no clean water, no antibiotics, and a life expectancy of 45.