Had a chance to try hand reaming a 2.75 inch bore today
Here is the finished muzzle guide......
And installed in the cannon muzzle......
Reamer in place for the start of the first trial run......
First batch of chips pushing ahead of the reamer !!!!
It takes about 10 minutes of hard pushing and twisting to ream about 2 inches of linear bore length. I made a gage and I think I am taking out about 0.015 on a radius or 0.030 on the diameter, which is more metal than I thought I would have to remove. I made about 6 inches of progress down the bore in three, 10 minute runs before my arms gave out. I detached a bicep tendon in my right arm 2 years ago that could not be repaired, so my right arm is fairly weak. If I had pulled the barrel off the carriage and stood it vertically, I could have weighted the reamer shaft and just turned the handle. But the barrel weighs nearly 600 pounds, so getting it off the carriage and building a vertical cradle is another project in itself. I think I have a way to apply a spring around the reamer shaft to apply tool pressure while I just turn the handle. And if I don't do all of that, in short increments, I can finish by hand. At the current rate of advance down the bore, it would take me another hour and twenty minutes of pushing and turning, so....not bad.... if I do it in increments of 10 to 20 minutes a day. The cut appears smooth and even and the bore gage indicates a nice straight cut. So far so good