What is the minus's of installing a hammer extension on a BLR with a folding Hammer?? Scope makes it uncomfortable lowering hammer

I don't know. I've had two different medium height mount/ring combos and both gave me adequate thumb clearance of the hammer.

First was an old Weaver K3 in Conetrol rings and mounts and now a Vortex 1.75-5x33 in a Dednutz mount.

Dan

When I got my .270 Win BLR in January of this year I too thought about adding a hammer extension and looked into it a bit. As I recall there are two different BLR hammer extensions - one for for pre-1992 models and one for 1992 and later models. I decided against adding a hammer extension as medium height Leupold rings on Millett BLR bases with a Vortex 3-9x40 scope afforded sufficient thumb clearence to safely manipulate the hammer.

Slower lock time...

This BLR I hunt with has the old style hammer, but plenty of room to manipulate the hammer without an extension.