Well, so far the most I've put thru it is 11 rounds at one time. The bore had well defined lands and grooves, and good shine all the way to the muzzle, no dry hard fouling, nice greasy muzzle. The Lee 515450 (and Lymans 515141) is a duplicate of the original military bullet, and carries lots of lubricant. Cleaning has been a tapwater patch, a dry patch, and a couple of Ballistol patchs.
I usually run a wet patch down the bore between skirmish runs, so I don't think there will be any fouling problems with this load. That's up in Nebraska, with really low humidity. I might try shooting a whole match down here in MO without anything other than a few breaths down the barrel now and then. I've done this with a Trapdoor carbine, the 22" barrels are a lot easier to maintain than the 30"+ barrels.
You come down here in March, you'll get to see if it works.