I did a thread a while back on the 2 boxes of BB I got for my 10mm Glock with Lone Wolf barrels. Half of the BBs wouldn't go into the chamber.You could see were the bullet was thru the case.They just weren't seated correctly. The rest fit fine and shot fine.Did feel the difference but didn't see any accuracy improvement. So I watched a test about BB and underwood ammo with a G20 and a S&W 29. For the g20 he used 155 gr underwood and 180gr? BB,so of course they didn't match up with the 44mag with 240gr ammo. Then I went to the Underwood website to find this ammo. Found some 220gr instead,hehehe. First thing I did when the UPS guy got here was to take the LW barrel out of the G20 so I could make sure they fit the ,as BB said,TOO tight chamber of the LW barrels. This stuff looks very nicely loaded. Can't wait to shoot it!