A lead ring can break off the botton of the skirt of a minie and remain in the bore. The type minie being fired usually determines if a lead ring will break off and remain in the bore. The minie designed for the Parker Hale P53 Enfield rifle musket (Lyman 575213-new style/510 gr.)from Dixie Gun Works (BU0901) will reduce the likelyhood of a lead ring being left behind in the bore. That minie is .576" to .577" OD and has 3 shallow grease grooves which makes for a thicker skirt wall and less of a groove that would allow a lead ring to break off. The new style minie is .000" to 001" undersize for the P-H .577" caliber P53 Enfield rifle musket and is somewhat more difficult to load, requiring three strokes of the rod rather than two. It was specifically designed to be fired in the Parker Hale P53 Enfield rifle musket with a .577" bore and high strength cold forged barrel.
The Confederate Gardner style minie (Lyman 577611 mold) minie also reduces the likelyhood of a lead ring being left in the bore. That minie has a skirt that is a 2-ring design and the skirt is .010" thicker than the skirt found on the Lyman 575213-OS minie, by having a smaller cavity. The Gardner style minie is .575" OD and shoots best with a heavier BP load, or 60 gr. 3f. If you are using an Armisport or Enfield for live firing, I would not fire the 575213-NS/510 gr. or 577611/530 gr. Confederate Gardner style minies because they require 60 gr. 3f BP or 70 gr. 2f BP to get them out of the barrel and down range with any accuracy.
Stick to the Lyman 575213-OS/460 gr. minie with 50 gr. 3f BP in an Armisport and Euroarms P53 Enfield rifle musket. I use Moyers Cast Bullets for target practice and they cost $7.50 for a nice little box of 25 minies. I have noticed Moyer's Cast Bullets now has a 2-month waiting period to fill cast lead minie orders due the demand for them and the labor intensive casting process. (www.moyerscastbullets.com ) They told me that most of their .575" OD minies for the .577" and .58 Cal. rifle muskets go to Texas.
A lead ring is more likely to be left in the bore after firing traditional .577" caliber Enfield rifle musket with a .575" OD/460 gr. minie (Lyman 575213-OS Old Style). Since those minies are undersize and if you use over 50 gr. 3f BP load, it can can blow off a lead ring, especially when the minie leaves the muzzle. To avoid that, reduce the 3f BP load from 50 gr. to 40 gr. or use 50 gr. 2f BP but you may sacrifice range and accuracy. But be advised, 3f BP burns hotter and fouls less than 2f BP.
It may be an good option to purchase a India P53 Enfield for $350 and use it just for reenactment events and use your ArmiSport, Parker Hale or Euro Arms P53 Enfield for live firing only. The India made P53 Enfield should never be used for live firing but they can easily tolerate up to 50 gr. 3f or 60 gr. 2f blanks. Many sutlers sell the India rifle muskets just for reenactors. I visited Frazer Brothers store in Dallas I noticed they had an India P53 Enfield replica there but they are not in their on-line catalog at this time. It looked nice enough to please your NCO, mainly because it is safer to use.(
www.frazerbrothers.com )