Bigger & Faster Probably Better
I have shot a few in S. Mississippi, most with rifles. But I shot one 3 years ago with a .45 Colt from a Ruger Bisley. It was a 255 grain SWC, going about 800 fps. I was close, within 20 feet, and it weighed only about 80 pounds, and it took 3-4 shots to stop it. I mostly got front shoulder shots. Of course it was already mad. Now I have 270 grain loads doing about 1100 fps in that Ruger, and I'm hoping for another try.
My problem is, if you hit them with a pistol in heavy cover, if it doesn't penetrate through and through, you don't have anything to track. I've tried to track several like that hit with a rifle and they just don't leave a blood trail like a whitetail. Recently, I think I hit a big sow (probably 200 lbs) broadside with a 260 grain .44 special running about 1000 fps, but could find no sign of a hit. I heard the bullet slap at about 50 yards, but I think the fat just swallowed up the bullet.
If you get the bullet placement just right on that Vaquero, you ought to be able to bring one down, but I'd use a rifle as the first choice. If you use the Ruger, plan to shoot more than once.