Ruger Vaquero 44/40 loading help

[Shane in WI]

I picked up a nearly new 44/40 Vaquero Ruger w/ 7 1/2" barrel in the polished stainless finish this week. I also bought dies to reload for this gun. I'm not looking to compete in cowboy shooting at this time, just a fun target load. I measured the back of each cylinder, along with the barrel at the muzzle and came up with .424. I am learning that there are many different sizes of bullets to choose from. How do I determine what to order and load? I found some Magnus RNFP 200 grain lead bullets at .426 that seemed to be what I'm looking for, but not sure. Idea's on powder and primer brands to try? I do have reloading books, just asking where to start. Any trouble shooting lead bullets through a stainless barrel?
Thanks for the information.

[John Traveler]

Shane,

It is not enough to measure your revolver barrel and cylinder bores with calipers.  That's not accurate enough to determine your best bullet diameter.

You need to push soft lead slugs (split shot fishing weights are good) or blackpowder gun lead balls through the barrel.  Use a wooden dowel and tap those pure lead slugs through.  Do the same with each cylinder chamber throat (the front of the cylijder) and get an average.  Measure THOSE with calipers or micrometer to get your best bullet diameter.

Ruger revolvers are notorious for having undersized cylinder throats and standard-sized barrel grooves. If that is what you have, you'll need a gunsmith to ream the chamber throats to fit the barrel groove diameter before you can get best accuracy.  This is a standard accurizing procedure for many revolvers, not just Ruger Vaqueros.

Like all old-west revolver cartridges, the .44-40 was originally a blackpowder lead bullet load.  Lead bullets won't hurt your stainless barrel.

HTH
John