Slants arn't all that effective, the 74 versions would be a way more effective one IMO, especially on a Mosin Nagant. Might be butt ugly but sure would work well I'd think, they work well on anything I've ever put them on and are my favorite brakes effectiveness wise. Eye of the beholder ya know, after all,, not all butts are ugly!!
There not all that expensive to buy eaither and the threads are the same so it could be used elswhere if you don't like the looks. Just my thoughts.