Posted 27 October 2004 - 09:08 AM
1- The only way to really know the position of the locking slots is to measure them using gages designed for the purpose. Most all WH ’28 guns suffer from this malady, but to differing extremes. A decision to repair this problem must be made in conjunction with the second issue; shape.
2- The shape of the locking slot is supposed to be a straight plane on 45 degree angle running out into the shelf that allows the ‘ears’ of the lock to move to the rear. Most WH guns have the corner at the intersection machined away at about 22.5 degrees and about ½ the length of the plane.
Often, the slots are not aligned with the centerline of the receiver, twisting the lock when the gun tries to open.
The combination of 1 & 2 above is poison. The last guns made (the 22 caliber serial numbered 45’s) don’t seem to have the 2ed problem, and if the position is not to far off, may be alright as is.
This is not the only issue addressed in a refurbish, but one of the major ones. While each gun is different, the average price for a complete refurbish of a WH 28 is about $1600 currently; the gun will look and function as good any Thompson once completed, and the repairs are good for life.
Let me add a test you can perform to determine the relative position of your locking slots: Remove the receiver from the frame and remove the pilot and recoil spring. If you can, place the receiver upside down in a vise with the bolt, lock and actuator in place. If you don’t have a vise, lay it on a table or bench with the actuator knob between two phone books or such and have a friend hold the receiver assy. Using a screwdriver or some other tool to engage the sear notch with one hand so you can push the bolt rearward, place a finger of the other hand on the back of the actuator pushing forward. In essence, your hands will be opposing each other to keep the bolt and actuator pushed together tightly, while in the fully forward position. While maintaining this opposing force, allow the entire assy to move rearward until the ears of the lock engage the locking slot in the receiver. The gap between the front of the bolt and the receiver wall that stops its forward motion should not be more that the thickness of a dime.