Yes, you'll need a forend spacer from H&R, Brownell's or Numrich. You might want to consider the steel spacer and trigger quard to go with a nice stock.
I have a bunch of Muellers, they're great scopes for the money and a bit more, and their CS is second to none. I have 2 TacIIs, an Eraticator, 2 Sport Dots and a Multi-shot. Their new APV is highly regarded at RFC, several are using them on high powered calibers too, not just rimfires.
Tim
www.muelleroptics.com