I would use this Crosman piercing needle pin washer to replace the Smith/Wesson model G piercing needle and washer with a countersunk rubber faucet washer to reseal the model G S/W rifle , it's almost the same diameter
no wonder S/W quit the airgun business, they don't make a good solid leak-proof piercing needle system that can be fixed with a simple faucet washer, U'll have to use their special size silicone seal, and not cheap or readily available