Gary,
If you buy replacement OEM Six series grips, they should come with the screw. You will probably need to go to someplace other than Ruger to get the grips if you want the factory issued grips. Ruger used to have the oversized grips (new old stock), but I think they might have sold all of them. You can check at ShopRuger.com. Otherwise, check Gunbroker or eBay. If buying from GB or eBay make sure the description says with grip screw. You can also check with www.gunpartscorp.com (Numrich) to get the grip screws and grips.