Well, admittedly I didn't do a thorough test...I had just finished a couple hours of pattern testing with copper plated shot and was too tired to start another hour long period of testing.
I simply tried almost the same load in this .62cal smoothbore that I use in the .62cal rifled barrel.
100grns FFg
.015" lubed patch (I use .018" in rifled bore)
.600" cast ball
Rock solid bench rest, 3" day-glow aim point sticker in the middle of the plate, good balls, no wind, etc:
1st ball hit top right edge of plate at 1 o'clock
2nd ball hit just off edge of plate at 8 o'clock
3rd ball hit edge of plate at 4 o'clock
I decided to end it right there and not waste any more powder and
lead...in hind sight I did not attempt to find/read the patches...it was an extremely tight PRB combo that I had to switch off and use a solid 3/8" brass rod with gorilla power to seat them...maybe they were tearing?
When I run out of more interesting things (to me) to do at the range, I may make a dedicated trip to the range with lots of different supplies to really try and wring out PRB accuracy from one of these jug choke barrels
