Yes CC I want to check older shotguns and I realize most 3, 3 1/2 chambers are new enough to be marked. I really dont need the 3 1/2, just made the long one to measure any chamber. It works great for brake actions. Then made the shorter 2 3/4 so I could get it in a pump action since the main thing I wanted to check was my 1897. Im going to make them for other gauges too. Pretty easy to do with a lathe. Most new ones you can buy are only marked for 2 3/4 and up and wouldnt fit in a pump so thats why I made them. Got a bright Idea to sell them so I put them up on ebay for $25 so will see what happens.