I have a Ruger Mark II Magnum in 375 H&H. I plan to use the irons as back-up sights. I have had the factory put in a lower front sight as it would not print my current ( and final load )
on target at 50 yards. Talked with the company & they sight all the rifles of this type with
270 grain loads. I use 300 grains only. I need to further lower the front bead. What if anything can I do to modify this bead and how do I go about it. I am relatively andy but have never attempted this type of work. Any help would be appreciated. I should mention that my gunsmith has passed away recently and there are
few smiths around here that I want working on my guns.

You can get different replacement blades for Rugers at NECG. Just go to the website.