About powder choices.....
In my 45 Colt experiments I found that faster burning powders only gained perhaps 100 or so FPS when fired from the rifle vs the revolver. Medium burning powders would gain perhaps 200 FPS; and the slow burning powders would gain 300+ FPS. Since your revolver is the weakest link, avoid using H-110 or W-296 powders since they aren't suitable to reduced loading to the pressure limitations of your Vaquero. Try to find some AA-9 or IMR-4227. In these days of shortages you may have to make substitutions...... I use the Lee 255 grain hand-cast RNFP bullet and it has a big flat point that cycles reliably in lever-guns. Work up a maximum safe load with either of those two powders or a comparable substitute and you should be able to safely get 1,000 or somewhat better FPS in your revolver, depending on powder. The same load should be clocking around 1,300 -1,400 from the rifle. Remember that you alone are responsible for the outcome of your handloading choices. It can be a safe and rewarding hobby or a dangerous mistake. Also, a lubricated cast bullet will give higher velocity than the same weight jacketed bullet at the same pressures with the same powders. Be safe, have fun, and good luck finding the right stuff.