Hi Bill !
I'm kinda old school when it comes to carry guns, and I generally follow and recommend what industry and law enforcement specialists and experts recommend. I'm talking about guys like Massad Ayoob.
Most recommend that absolutely no non-factory modifications be made to a gun, even by a licensed gunsmith. When I say non-factory, I mean that something like the Glock factory trigger kits would be acceptable, but nothing aftermarket, since there is no way to predict it's overall effect on the functionality of the gun. Sights and reasonable grips and things like that are fine.
God forbid, if you are involved in a questionable shooting (or ANY shooting for that matter) and your gun is confiscated (which it most likely WILL BE) for analysis, if they find trigger mods, and fire control mods, and things that indicate amateur gunsmithing, that will just be legal ammunition for the perp's lawyer, or his estate's lawyer. They will try to portray you as an irresponsible gun nut who wasn't satisfied with the gun as it came from the manufacturer, that you had to make it even MORE deadly. If by chance the shooting was accidental, for example you were holding someone at gunpoint and it went off, and THEN they find something .... what do you think the result of that will be ?
This is the exact reason that DA/SA and DA guns like the Glocks came about. It was found that almost ANYBODY has a muscular reaction to any unanticipated move when holding someone at gunpoint. Guns like SA 1911's and Revolvers in SA mode, were found to easily go off if there was even a slight muscle twitch in an adrenaline fuelled moment. Cops who are trained this way were shooting people by accident and the liability suits were skyrocketing. Now virtually ALL police departments carry DA/SA guns because of this liability.
Let's say you are involved in a shooting where the defense is claiming accidental unwarranted shooting. If you are carrying a factory stock gun, you can get Ruger involved, with all their experts and technical testimony. Let's say you PAID a gunsmith to work on the gun. You can get HIM involved, and licensed gunsmiths carry insurance and have good lawyers available. Now let's say that YOU did the work, YOU put in a lighter trigger that was NOT authorized by Ruger. Ruger will say ... 'Hey ... the gun was safe when it left the factory ... the user modified it with a non-factory untested part ... we don't allow or recommend that so it's THE USER'S problem'.
They'll get you on the stand and cross-examine you. Where is your gunsmithing degree from ? When did you graduate ? What gunsmith experience do you have ? Why did you feel that the gun as it came from Ruger wasn't deadly enough ? ETC ETC blah blah blah. So Mr Smith, you have NO gunsmithing degree, you have NO gunsmithing experience, and yet you modified your gun to have a LIGHTER trigger BY YOURSELF, with a part that was NOT authorized by the gun's manufacturer, and my client was shot or killed because of your irresponsibility. YOU sir, are going to jail, because you shot/killed an innocent man with your home-gunsmithed UNSAFE gun.
We've had this discussion many times before here, so I'm not going to respond to any opposing views ... that's already been done. This in a nutshell is what you'll read in Massad Ayoob's absolutely excellent book ... In The Gravest Extreme. I highly recommend reading that book to read about this issue as well as other issues of liability when carrying a weapon.
After reading that book, there are MANY people who decide not to carry a gun at all. The minute you shoot someone the entire legal system switches from protecting you to convicting you .... many times even if it's a righteous shoot.
It's great reading, and should be required for anyone contemplating carrying a gun for self defense.
Mod the hell out of your range guns, but buy a gun for carry that you can live with and shoot well as it came from the factory. That will give you the best possible legal defense if you ever have to use it for real. It only makes sense. There will now be a bunch of non-qualified amateur legal eagles come on here and say that I'm full of it, and to show them cases where that has happened, etc, etc. All I can say is ... read the book or pay the money and talk to a lawyer well versed in firearms cases .... see what they have to say .....
Sorry about the lengthy reply.
REV