From the previous 20 MM post. Tailgunner mailed an empty 20MM cartridge for a guitar slide. It arrived today and I cut it off at the base and the top inch or so. Deburred and polished, picture of 20MM slide, cut off 20MM base and smaller 50 BMG slide.
I don't know how the new 20MM slide sounds yet. Her guitar teacher in on vacation this week but she starts up with lessons again next week. He had a commercial brass slide he gave me to measure his size and it was quite a bit thicker than the 20MM casing. If it sounds good the cartridge case slide might be easier to handle than a heavy one. The daughters 50 caliber slide sounds great, 60 year old brass may have hardened some from age.