Bob the beauty of bagging in your nocks is the fact that they make so many different mil plastics, today. Your chances of finding one that works is almost 100%. It's also a good thing when you bust one, practicing....and can replace it VERY easily.

The bags the merchandise from my shop comes in worked perfectly for my target arrows, this past winter. I tried maybe 4-5 different mils before finding one that worked, though.

Good luck.