Grip screw Fitment issue 1851/1871

[Crawfish997]

I bought a set of pietta screws for an 1851 navy but the grip frame and trigger guard screw heads are too big and wont fit down into the grip frame. I tried them on a pietta 1871 open top and a uberti 1971 open top and had the exact same issue, it seems there are actually 2 different sized grip frame screws used on these guns and i have the wrong ones, could anyone help me out with finding the Smaller of the two?

 

[M. De Land]

I bought a set of pietta screws for an 1851 navy but the grip frame and trigger guard screw heads are too big and wont fit down into the grip frame. I tried them on a pietta 1871 open top and a uberti 1971 open top and had the exact same issue, it seems there are actually 2 different sized grip frame screws used on these guns and i have the wrong ones, could anyone help me out with finding the Smaller of the two?

Yeah, the screw that goes into the bottom of the grip butt has a different head on it than the other five. I'd just chuck them up in a hand drill and put a file to them, until they fit the Fillister screw seats then touch up blue the perimeters.