there are lotsa you tube vids with amateurs tweaking triggers, hammers (in conjunction with beavertails), firing pins, etc. i was always under the impression that messing with the firing mechanism of any gun, including "just drop in replace" parts, was work for a competent gunsmith and no one less. that would make those kinda vids unsafe in every way. changing grips, recoil springs, sights, etc, not included. your comments?