Hmm - don't know anything about them, but one worked very well for Lt. John George in the Pacific.

I have an action here that is a cross between a 98 and a 03 Springfield - made in England in the 80's. Seems to work fine so far. Can't remember what they are called, might even be on the action - to lazy right now to open up the safe and have a look-see.
It's Miller time - well, not exactly, it's Sleeman's Honey Brown time.
Cheers!