Wasn't able to pick them up until today. Cleaned up the ends really quick and pushed a slug through. Went very smoothly. Grabbed the mic and measured the slug at .2174" so should be perfect with .217 slugs. I'll get some borescope footage too of the inside and post as well. Hopefully find time to fit one to my Kral NP-500 this weekend. It should push 26gr knockouts around 940. I only have a few slugs here in .217 but I think they are 22, 24 and 26gr AVS plus FX hybrid and JSB knockouts. The MKII knockouts are .2165 with a semiskirt so they may do well also. I'll have to order some plus will dial back to 900fps with JSB 18gr and give it a go also.