I have a Browning MkIII Practical that I bought used some time ago.  No idea how many rounds are through it.  But I recently noticed that the underside of the slide has some peening right next to the FP block.  It is on the surface that pushes the hammer back during cycling.  I can't figure out what's causing this - it doesn't impact function, but if I pull the slide slowly, I can feel the hammer go over it.  No unusual wear is evident on the hammer.  

Is this a known problem or indicate some deeper issue?  The camera flash makes the surface look rougher than it really is, but you can see how the material has been pushed down and to the sides.  This gun has a C&S improved sear lever with the relocated pivot point, if that makes any difference.  

My guess is the hammer is bouncing?

light hammer spring is allowing the slide and hammer to come back quicker. Hammer then bounces.

That makes sense.  The hammer spring does feel lighter than typical.  I wonder if replacing it with a standard spring would prevent the peening from getting any worse.  

Welding it up is probably the only way to really repair it.

It’s pretty common today for Bubbas to install a lighter hammer spring to improve trigger pull, without realizing the other things that are in play.

For example with any blow back or delayed blow back operated pistol the resistance provided by the hammer being recocked by the slide is a large part of the resistance designed into the mechanism to delay the opening of the breech.

Consequently a lighter hammer spring has to be balanced by a heavier recoil spring.  That usually doesn’t  happen.  Plus as recoil springs cycle they get weaker over time and many 1911s,  hi powers, CZ 75s, Beretta 92s, etc end up running with worn out recoil springs along with lighter hammer springs.  Bad things happen and the Bubbas act surprised.