Next step is to loose a bunch of unnecessary barrel length that makes these guns cumbersome to carry, here trimmed to a true 4" length. Added is a NOS Steel cam cut ejector rod housing from the old true 4" army san-marco revolvers and a colt style crescent ejector rod button.
The part was inexpensive because the upper left screw hole was drilled twice. Crooked once and then oversize and crooked again leaving a figure 8 hole. Drilled it out on the press with the smallest bit that would clean up most of the hole, fitted a brass pin and tinned and soldered with Hi Force 44 silver solder. Strong enough. Incidentally, I found water base flux and a low flame works best with Hi Force. Much better and easier to solder the strongest joints with good old water base plumbers pipe flux. Later, I'll measure, mark and drill and countersink a new hole for the upper left grip screw.
First fitting going well. New left upper grip hole drilled and countersunk at .619" CTC. Pretty close bolt up of Italian grip to American frame. I'm pleased, only minor fitting at the aft end of the frame and the width is at least a good as a Ruger factory grip frame.
Factory blue on this one is so good I'm moving slow as I'd like to preserve the blue throughout the fitting process. First fit of the Uberti brass trigger guard to the frame and grip. Will have to get the trigger guard exactly where i want it and then bring the grip evenly into the strap and back of the ruger frame. Just try and try again till it slides right into place.
Getting back to sparkly goodness. Here the lower tang has been heated dull red in a dark room and bent forward 3/16" to line up with the curvature of the cast grip. Front screw hole in the trigger guard is plugged with brass and moved back 2/3 hole to line up with the factory hole in the frame. Counter bored, a ruger back strap screw is a perfect fit for a new front trigger guard screw. Also, the two rear trigger guard screws were replaced with back strap screws for a perfect clamp on the Uberti trigger guard. Finally, the grip is drilled and counter bored under its eagle cap in order to fit a screw which secures the tail of the trigger guard to the grip itself. Rock solid. Started some of the grinding of casting flash. Next step is to outfit the trigger guard to function with the old model trigger return spring and plunger.
Next step is making up a simple jig to copy the Ruger Trigger Plunger hole over to the Uberti Brass Trigger guard. The hole is .170 diameter and .650 deep. When looking at the bottom of the trigger guard, the hole is 10 degrees to one side and 15 degrees down from the frame base line as measured from the proper sized drill bit, these angles repeat pretty well on several surfaces of both trigger guards. (important as they are slightly different shapes and its good to have common reference points to align the brass guard to be drilled). I used the original XR3RED grip frame to establish the angles. When mounted on the leveled drill press pad, the drill bit will be perfectly vertical. After some additional work on the grip frames trigger slot, I'll be ready to step drill the trigger plunger hole in stages on the drill press. Every Italian part is slightly different throughout the years, so each modification may require a new jig, easy enough from scrap wood and a few minutes work to establish the angles.
Drill out the hole for the trigger plunger, polish the hole and the plunger and check fit. Drill all the way out the back, the trigger guard is thinner than the aluminum factory housing and a capture pin/screw will be installed to retain the spring from the backside. Some more fitting of the trigger, it rubs on one side of the slot and is a bit long, rubbing the edge of the trigger on the inside of the guard.
In and out hunting but between trips, got the inside of the trigger tail profiled for conversion from flat spring to coil and since there is a dearth of space inside the brass grip, trying and upside down spring seat. I think it'll fit and have all the needed clearances for the mainspring and strut.
Will have enough room for the mainspring and strut to run unencumbered inside the grip in place of the Colt original flat spring. Also, the trigger return plunger functions correctly and all the clearances needed for the trigger were made within the trigger guard loop. So, no need to re-blue a shortened trigger. Finally, a stud retains the trigger plunger spring at the rear.
long slow work now...final fitting. Getting the trigger guard done first, blending in difficult spots. Alternately polish and file/sand, then polish again. Helps to take photos as you go....easier to see the flaws on a big picture and then go back to the work at hand.