i just bought a used remington 700 KS fiberglass/graphite stock for my remington 7mm ultra mag. upon further inspection, i noticed a crack forward of the magazine well going toward the recoil lug area, but not quite to the recoil lug. the seller refuses to refund my $$. so i'm stuck with a cracked stock. is it possible to fix the crack? should i use a hacksaw to enlarge the crack, fill it with epoxy and add a reinforcing screw?

I believe they are McMillans on the KS not sure. Call Remington custom shop and find out. If it is a McMillian they will probably fix it for free. I would try the company that made it before I would send it back to Remington. Either way I would try to get it fixed via warranty before I epoxied it myself. The cost of materials and the PIA as factor would be worth sending it off. If all else fails it should not be a hard fix.

Enlarge the crack so the epoxy can get in. Reinforcing screws should run across the crack, not along it.
Before you do anything however, you should contact the maker (Remington?) to see if they will warrenty the stock.