After reading these posts on the various gages, I went to the basement and modified my Manson/Clymer gage that I used vertically suspended. I drilled a hole now in the aluminum block and tapped it for a 3/8" eyebolt to put my finger in.
To me it was very awkward to use and to try and find a place to put the barrels so they were steady as I couldn't put them on a bench so I used a wood workers vice with soft pine jaws to hold them.
On mine the rod with the indicator on it is 3/4" steel and 36" long and the barrel rod is 5/8" steel zinc plated also 36" long. I had them sticking out of the aluminum block 20". I don't know how long Mike's rods are, but I'm guessing to measure 32" barrels they must be at least 16" long.
This might be a good gage if I got to using it more and cut the rods to a set length and lightened up the aluminum block. You still have to use two hands initially to raise the indicator needle. In moving it into the barrel, you also have to make sure you stay parallel, so it's watching the needle and watching to see if you are parallel.
So far in comparison, I like the vertical suspeneded mounting better. For some that say it is not accurate I don't understand that, the indicator is at one spot all the time and the barrels are being moved, even if they are not exactly parallel the reading is not affected because the spring is keeping that part of the barrel snug against the ball.
I think that the Galazan gage is basically the same as the suspended one, the bottom brass cone keeps the breech or muzzle centered, and the spring keeps the barrel in contact with the ball, you can rotate the barrel on the bottom axis and read from top rib to bottom rib very easily from what I see so far.
The Hosford gage looks like it works great measuring from the muzzle, but not so much as from the breech, the barrels are on a bench loose now, and to me very hard to measure accurately, and that is where my main concerns are.
