IIRC it was something that they offered with a rifle as an option for some extra money. I dont think they installed it on the rifle for you. We have seen 1 or 2 on savage rifles. Here are some of them on Mossberg .22s

http://www.rimfirecentral.com/forums/showthread.php?t=486253


"We're all going to have so much [bleep] fun we'll need plastic surgery to remove our god damn smiles." - Clark Griswold

Remembering The 99
http://www.blurb.com/bookstore/detail/1163424