Just installed One Ragged Holes apertures on my 336c 30-30 and 1895 Guide Gun (45-70). Ran out of time to solve the problem, but it appears I may not be able to lower the rear sight enough on the elevator to bring my shots to POA.

What's left at that point? New handloads? Never run into this before.

If you like your new rear sight and like your current load the solution is to get a higher front sight.

Ken hit the nail on the head. Brownell's and Midway both sell replacement sights and Brownell's has a sight height calculator in their tech section.

Old sticky...but useful for you:
http://www.shootersforum.com/showthread.htm?t=22575

OK, good stuff, guys. I knew this was the right place. Thanks.