I have a 20 inch Government profile that was built in about October. I have only had time to fire about 100 rounds thru it and here is the problem.
The roll pin just behind the trigger wants to walk out to the right side when rapid fireing.
Any thoughts on correction?

Roll pins are easy to open up a touch with a pair of pliers.

Well pliers tend to make a roll pin smaller unless you really flatten it out. You could just buy a new roll pin, they're not exactly expensive. Brownells sells them for $0.75, so next time you're ordering some Kroil or springs, just add it to your order.
Another solution, and this is untested by me in this particular situation but I don't see why it wouldn't work, is to use some Loctite on the pin. I've seen it work great to prevent dovetailed sights from riding out, I don't see why it couldn't work in your situation. It's not like that pin is removed frequently anyway, so a few drops of red Loctite will probably do the trick.
Good luck.

Quoted: The roll pin just behind the trigger

Are you referring to the trigger guard roll pin? If so, and it is the type that is slit down the side, remove it and enlarge it by using a 1/16" tapered pin punch... With the pin removed and one end placed up against a solid steel surface (between the slightly open jaws of a vise works well), place the punch into the pins opening, tap the punch with a hammer to fatten/enlarge the roll pin... Don't over do it or the pin will be to fat, not allowing it to fit back into the hole... You may have to knock the pin off of the punch if it gets stuck...

This will only work with the roll pin that's has the slit down the side... It will not work with a true roll pin that is like a scroll...