Grip safety issue

The grip safety on my Les Baer Hardball gun isn't working properly. The hammer will drop when the trigger is pulled and without the safety being depressed but is prevented from falling if the safety is pushed upward. Am I right in assuming that the fix is to bend the right-hand leg of the sear spring out to increase tension on the grip safety? Or is there more to it?

Yes bending the right side of the sear spring will increase tension on your grip safety. Is this a new problem that just showed up or have you changed some parts or did trigger work recently. If it you have many rounds through it it may be time for a new spring.

The only thing changed is the mainspring housing. The gun recently went back to LB because of occasional doubling, which they corrected. I put the new MSH (arched) in after that.

The part of the grip safety that interfaces the trigger may have been fitted incorrectly.  If the spring adjustment doesn't fix it, it sounds like another "built-in" problem.

Adjusted the spring outward and reinstalled the arched MSH: no change. Replaced the arched MSH with the original LB part, numbered to the gun: all set. Is there a modification I can make to the arched housing to make it a safe fit? I prefer the arched, but I prefer a safe weapon a lot more.

Found another arched MSH, installed it, and found the Baer grip safety works perfectly. Something peculiar to the other arched housing was causing the problem. It's a little late now but tomorrow I'll put the offending part in my Colt wad gun to see if it causes the grip safety to fail in that gun as well. I'm using the same mainspring and associated parts with each try.

You can fit the MSH by taking material off of the MSH where the hooks of the grip safety stop against it.  
You should be able to do this without any of the filed area being visible when the parts are assembled.
Let me know if you need pictures.

+1

There are no drop-in parts on a M1911.  The foregoing is the proper fitting process for a main spring housing.  Un-fitted; the grip safety simply could not swing out far enough to release.

Jim

Thanks very much.