I bought some brass stripper clips from a guy off of ebay. I cant remember his ID but his come highly recommended. New made clips can be hit or miss and sometimes lightly oiling them can help. I have used Czech and never had problems with it. It is great stuff. Brass Fetcher has done testing on it.
148gr Czech FMJ (silver painted tip) I got mine from Aim Surplus.
AIM Czech 7.62x54R 147grn FMJ Light Ball Czech 7.62x54R 147grn FMJ Light Ball
Make sure to pick up a cleaning kit. Not only is it a cool acessory but that "strange" shaped tool it used to check the firing pin protrustion which is very important. 7.62x54r.net is a excellent site that contains everything Mosin with very knowledgeable people on the boards. Just dont talk about sporterizing on there they dont take too kindly to that blasphemy.