I want to do the same thing to one of the Green Mountain Barrels. I was thinking of doing it to my .58 caliber, but talked myself out of it.

That is some good shooting. I bet that 25 yard group had you laughing out loud. The group differences could be attributed to patches, lube, the barrel getting more fouled, wind, lots of things. Roundballs at long distance is hard shooting. You did very well.