I am following this thread with great interest. Denis and I, HobbyMan form Canada myself are doing exactly this but with a twist. As a test, we elected to order powder burner liners from Brownells Gun Smithing Supplies in .224. They are only a couple of thousandths larger in dia. that the FX liners, and Denis made the tube and thimbles to fit them. Mine in a Rainstorm II that is set up for .257 and .25 slug shooting currently, and his a .30 impact.
this is a test, and only a test to see if it is viable project or not. If successful, .172 slugs will be the next project. I would love to try this in the upcoming Raptor being produced by JSAR. You've just gotta love a good project!
I love the workmanship that went into your project. I too had to lengthen the probe to get the seat that I was looking for. I was amazed at the finish inside the Brownells liners. they look virtual honed. But I honed mine anyway. LOL . It's been a bit of work, but it is now shooting bullets I cast from Decked and modded NOE Monds. that are now weighting 29.3 grs. Accuracy has been good at 880, batter at 980, and continues to be good at 1030.
Anxious to see where you find the best accuracy with slugs. I do a bit of testing for Nick, of NSA, some for Varmint Knockers, and will be testing the new HP system for NOE.
Rough life, but someone has to do it! :<)
Wishing you Fantastic Luck with such an outstanding an forward thinking project! ;<)
Knife/Mike