If you reload, you probably already have a dial caliper. If not, they can be obtained from a variety of sources. If you do any gun work or reloading, it will be invaluable. Measure the cylinder notches on both ends and in the middle of each bolt notch. Remember, the bolt notches are offset so make sure the calipers are square to the notch. On our project revolver all the notches measured around .153” on the ends and .145” in the middle. Photos 4 and 5. As we had previously diagnosed, the bolt appeared too wide and was peening the bolt notches. Our bolt measures .157”. Photo 6.
So, our original diagnosis was correct, the bolt is clearly wider than the bolt notches. Just to double check your measurements, try to insert the bolt into the bolt notches. Remember, the notches are offset so the sides of the bolt must be kept parallel with the sides of the bolt notches. Photo 7. Check all of your notches and try the bolt in each notch. IF your cylinder bolt measurements are all greater than the width of the bolt and the bolt it goes into all the notches, then you can sit back and relax and skip the next operation. On our project revolver, the bolt would not go into any of the cylinder notches, especially since all of the notches were already showing signs of peening. Photo 8 shows a cylinder that was already ruined from peening and also shows the results of an attempt to square the notches with a Dremel.
The cylinders on our black powder revolver are soft. Thus, we can re-square the notches with a de-burring tool like that pictured in Part 1. Put the point of the tool in the bottom of the notch (on the same side as the burr) and make sure the side of the blade forms a 90 degree angle with the bottom of the notch and drag the blade along the notch. This may need to be done a couple of times, but the tool will cut the burr away and leave a nice clean square notch cut. Do this for all notches that have damage. On our project revolver, this was all six notches. Re-measure all of the notches; they
should now be fairly uniform. If the middle measurement on any notch is still markedly smaller than the ends, you may need to remove a little more material with the de-burring tool. Now determine the smallest notch. On our project revolver, all the notches were between .152” and .154”. In Part 1 we marked the bolt with a black Sharpie. Keeping the cut as square as possible, stone this area down until it is .002” or .003” thinner than your smallest notch. On our project revolver the bolt was cut from .157” to .150”. Photo
9.Put the hammer in the frame and then the bolt and bolt/trigger spring. (You don’t need to install the trigger.) Put on the back strap so you know the maximum the hammer can be cocked when the revolver is fully assembled.