The couple that I have done were the injection molded kind that doesen't respond well to anything sticking to it , I scuffed the heck out of it with 40grit sand paper and drilled a bunch of 1/4" holes about 1/8" deep of so , this way the epoxy has somthing to get into and lock hold of.
I used the Devcon Plastic Steel putty and smeared it into the holes reay well and ended up leaving about a 1/8" layer on the stock where I wanted the texture , had to wait a while till it started to set up and the first time I tried the tapping method with a small paint stir stick the second time i used a little roler i made out of a piece of heavy knurled aluminum , it takes a few tries but eventualy you can get it to look like it was checkerd. I also tried just useing some 36 grit sand paper and just pressing it to the bedding compound as it was semi setup and that worked ok as well. The best thing to do is try a few differant things with the bedding material setup at differant time before you get to work on the stock.
Also you'll want to use some sort of release agent , I found that a very lite sprinkle of some fine talcum powder worked well , just dust the bedding rather than the thing your gonna use for the texture , think of it like roling out dough for bread.
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