[JAMMER]

Steve the closed height should be about 5 inches and the attachments would be pins about 1/8 inch or less on the top and bottom. I was thinking a 1 inch lower tube and then a 7/8 3/4 5/8 1/2 3/8 and 1/4 with the 7/8 to 1/4 being the stages and 4 1/2 inches long would give you about 30 inches. This way if you wanted a shorter cylinder just subtract a stage or start with a smaller bottom tube and go up. The hole problem is the sealing of the stages, not to tight and not to loose. This is only a suggestion to the problem and I think I am going to give it a try either with O rings or packing or both. Ed