Questions - Opening 1860 RM rear sight

[Athena Jake]

Have a pair of the 1860 RMs and have read about having the V on the hammer opened up a bit.

So, I figured using a triangular file, but wondering where to get this?

Can I get away with a fine tooth 3 square "EZ lap" diamond file from Brownell's?
Or is this over kill?

I know the hammer is surfaced hardened and diamond files were recommended (somewhere)

[Pettifogger]

Sometimes a regular file will work, sometimes it won't.  On some hammers the hardening is only a couple of thousands thick.  On others the darn things are harder than glass quite of ways in.  What I use is a 1/8" round diamond file and file a "U" notch.

[Ransom Gaer]

On my 1860 Armies I turned the V notches into square slots and opened them up just a bit.  Works good.

Ransom Gaer

[Montana Slim]

Used a Dremel tool w/cutt-off tool to slightly open, deepen the V-groove.
Why do anything else with such a great design?

Regards,
Slim