I have a 66-3 that is Magna-Ported and has the same muzzle treatment as the 629 above. The hammer and trigger have been polished. I bought it this way.

I also have a recently purchased 66 no-dash that is original without Magna-Porting.

The 66-3 Magna-Porting helps with muzzle flip and felt recoil. My wife likes shooting the 66-3 but won't touch the no-dash. She says it hurts when she shoots full loads.