Another '51 Navy conversion firing pin question

[Will Sellit]

On another topic I had mentioned a couple problems I had with a 2nd generation Colt '51 Navy R&D conversion that I just got.
Most of the problems were taken care of except one.
I was having a problem with the firing pin sticking if I accidentlally dry fired a chamber. My gunsmith took the pin and bushing out and found that the bushing was peened from the notch in the hammer when I dry fired it. He fixed the pin and bushing and it worked fine until I dry fired it again and it started to get "sticky" again. I am quite sure if it happens again the firing pin will stick like it did before.
I have trouble believing that this is normal so I would like your opinions on what needs to be done to correct this. I feel it is something to do with the hammer, but being very ignorant about these guns I probably am wrong.
Again your help is very much appreciated.

[Smokin Gun]

Lighten the Mainsring on your Navy...take the grip off and back off the mainspring screw(1/4 turn to start 1-2 turns if you need to)  till it lightens the hammer but still set off a primer. And don't dry fire it, at least put empty fired cases in the chambers if you need to dry fire it.

[Presidio]

Ya' kin get yerself some "Snap Caps" if'n yer gonna be dry firing any.  They're spring loaded blanks that absorb the shock of hammer falls on cylinder firin' pins.  They also work great in yer long gun and shotgun fer practicin' at home.  But, please do yerself a favor - try yer best and keep from dry firin' them guns on empty cylinders - it'll be a shore way ta' mess any firearm up.

Ditto on lightin' the hammer spring.  Jest a little at a time like Smokin_Gun said.