I was at the range with my Encore today, shooting the 30-06 Pro-hunter barrel.
Anyway, after about 10 rds, my next shot was a "dud".... Tried a couple a more cartridges, and none of them would fire. The primer was getting dimpled, but not firing. Anyway, I noticed that my hammer extension had worked loose. I removed it completely, and the rifle fired fine again. I guess the loose hammer extension was just enough to slow the hammer impact and kept the primer from firing.
Anyway, I know a lot of people have these things on their Encores, and I thought I'd share my experience. I think I'm just gonna leave the darn thing off. Wouldn't want a misfire at an unopportune moment, if you know what I mean.
BTW, the Barrel is a pro-hunter, but the reciever is not. I bought it a month or so before the PH's came out. So, that's why I had the hammer extension......