1) Yes, not a problem. It IS all about putting it where it belongs, confident accuracy and one in the boiler room with that load will do the job just fine.
2) Hard say-in, might be the 495 with a .015 will be better. I've always improved accuracy with tighter patch/ball combos, the only thing you can do is try. You already have one load that you know works, you can always go back to that.
When I work up different combos, I always have to adjust the powder too, working from low to high in 5grn increments