The OS cards should be only about 1/10" in thick, and are flexible. Use 4 OS cards over the powder. If you have a short starter, you can push them beyond the choke, one at a time, using a finger, and straighten them out with your short starter, before running all 4 down onto the powder. Then put in your shot, and cover with 2 os cards. Put off center holes in the cards and load them so the holes don't line up.( I do 12,3,6 & 9 o'clock on the 4 cards; 12 & 6 o'clock on the two OS Cards.) The 4 cards going over the powder will not " diesel" on you if the flash channel is open and the nipple is clear to allow air to escape through the powder and out the nipple. The 2 os card will diesel on you, unless you have the holes in the cards to let air out. When the cards hit the air at the muzzle, air goes through the holes, and separates the individual cards, so that they lose velocity quickly and fall down out of the line of travel of the shot. This lets you go into the field with just the one type of card or wad, and this makes loading any choked barrel much faster.
The thicker, 1/8 hard cardboard OP wads are almost impossible to fit down through a choke. If you manage to get them through the choke, they are damaged on their edges, and do not seal the gases back very well. By using 4 thin, os cards, you can easily get them past the choke, and by rotating which angle on the arc you put the cards into the choke, any damage to an edge will be covered by one of the other cards.
To lube the barrel, carry greased cleaning patches, and put them in front of the jag before you run the OS cards down on the shot. This lubes the barrel, which reduces friction with the shot, reducing or eliminating lead from rubbing off on the barrel, IN ADDITION TO keeping any powder residue soft. The grease also protects your bore from any rust while in the field. I carry them in a plastic Zip lock baggie, in a pocket, and some paper towels in another pocket to clean my hands after loading, and clean off the rod and jag before putting them back into the pipes. A regular towel also does this work well, and goes in the washer at the end of the day.
