3M makes a textured matte clear coat. It's designed for steel stair treads and such for traction. I used this over krylon on a vanguard stock a few years ago, still going strong.
Be sure to do your prep well. Clean all oils off with methyl hydrate. I have yet to have krylon flake. Rub off yes... but flake no. Unless there is some wonder material in that plastic, it should stick. And if you are at all concerned, try a test patch and try ruffing, scuffing, peeling off after it has set for a day or two. And you can also try lightly scuffing with 200 grit to ensure adhesion. Good luck.
Elky.
Yes, I think if it is flaking off for some people that would imply improper surface prep. The paint rubbing off here and there is no big deal as far as I am concerned.
Are those who painted their flamer stocks removing the orange first and getting down to the base plastic?