I posted this in the Gunsmithing Section but got no reply.
I wanted to change the location of the trigger on a 725 but the set screw will not come loose. After failed attempts to loosen it, the screw is now rounded out. The gun is several years old and I never tried to change the trigger location. I suppose the next step is to drill out the screw but that would destroy the trigger, although I have others.
Any ideas?

Sounds like that screw is stuck pretty good. I would put the gun in a padded vice or other secure fixture so the screw head is facing up and put a drop of Kroil or other good penetrating oil on it and let it soak in for a week. Then I'd try the allen wrench again or maybe go up to the next size wrench. If that doesn't work you may be able to get a small flat blade screw driver in there and start turning the screw. Whatever you do, protect the trigger guard and rest of the gun from any damage. The trigger shoe and screw are easily replaced once you get them off of the gun.

Thanks for the advice. I thought of the screwdriver thing as That has worked for me on some other things (not guns). I will get some oil.

Should have used some heat on it before you stripped the head out, now probable a die grinder to remove it and wreck the trigger , luckily 725 comes with 3, so you will need to order a new retainer screw from browning

I tried everything before loosing patience and cutting the trigger in two with a hacksaw. I was very careful not to cut too deep. Anyway the issue is solved, as I had 5 other triggers as 3 came with the two Browning I own. It would be a good idea to loosen the set screw very year and re-tighten . After several years and 1000s of rounds things can get mighty tight.