I use to have a problem with the magazine release digging into my middle finger when firing the glock left handed. I carry a glock both on and off duty, and being left handed I just HAD to come up with a way to fix this. Here is what I did. I removed the magazine release from the frame, with an X-acto knife I cut off the lower rear corner of the release at a 45% angle. I reinstalled the mag release. Done! It's that simple and now I don't even notice the release is there (unless I handle someone else's Glock). I have never had a problem with the releasing the mag. And I made sure that our armorer was OK with it.