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First time I've been on the site for a couple of years IIRC, just wanted to post about re-chambering the Bartlein in 22 Grendel with a 22 Grinch reamer that I ordered in from PTG. I had to wait on the resize reamer for this chambering, but now have made a die set on Newlon die blanks, going with a sizer with neck bushing, and a seater that I ordered with the Mitutoyo micrometer top, which is very nice. Troy makes his blanks out of stainless that can be heat treated to harden them if you feel the need. The Grinch reamer will clean up the body of the 22 Grendel chamber, but since the Grinch was designed for bench rest competition, it has a tight neck, and so needs case necks turned. If I were starting over, I'd spec a reamer neck of at least .255" dia, though it would probably be safer to go with .256", as that's what my 22 Grendel chamber print shows, and I wouldn't have to turn necks. Referring to the 22 Grendel & 22 Grinch prints, setting the bbl back .030" still leaves all or nearly all the neck at the original .256" dia - I need to do a chamber cast with CeroSafe to find out for sure. Or, I could play it safe and just pull the bbl and set it back a full .200" so it would cut out the entire original neck, and freshen the leade at the same time. All this is the long way to say that I wish I'd have gone with the Grinch chamber in the 1st place...
Fireforming in the Grinch chamber blows the shoulder .050" forward, and the body diameter at the shoulder is .005" larger than my 22 Grendel print shows, so the Grinch has a bit more case capacity. After necking Starline 6.5 Grendel down to 22 in two steps by changing neck bushings in a Redding 6.5 Grendel sizer, the safe thing to do if you want brass to last very long is to anneal before fireforming in the Grinch chamber. The first few cases I fireformed had neck splits, which was no surprise, since after the final neck down to 22, I had to expand the necks a few thou in order to be able to run them over the neck turning mandrel - it's no wonder they were brittle enough to split after all that forming & then expanding to turn necks. As hard as it can be to find Grendel brass, annealing is a small price to pay for normal brass life. It's getting a little late for me to resize my photo files, as they're all too large to fit. Might just reduce the quality & size parameters in the camera and shoot new photos later. Hopefully, we'll get some of the rain/snow mix they're forecasting for this weekend, and I'll have time to mess with it so I can show photos of the Grinch brass compared to 6.5 Grendel, 6 RAT, 22 Grendel, and finally, 22 Grinch.
Fireforming in the Grinch chamber blows the shoulder .050" forward, and the body diameter at the shoulder is .005" larger than my 22 Grendel print shows, so the Grinch has a bit more case capacity. After necking Starline 6.5 Grendel down to 22 in two steps by changing neck bushings in a Redding 6.5 Grendel sizer, the safe thing to do if you want brass to last very long is to anneal before fireforming in the Grinch chamber. The first few cases I fireformed had neck splits, which was no surprise, since after the final neck down to 22, I had to expand the necks a few thou in order to be able to run them over the neck turning mandrel - it's no wonder they were brittle enough to split after all that forming & then expanding to turn necks. As hard as it can be to find Grendel brass, annealing is a small price to pay for normal brass life. It's getting a little late for me to resize my photo files, as they're all too large to fit. Might just reduce the quality & size parameters in the camera and shoot new photos later. Hopefully, we'll get some of the rain/snow mix they're forecasting for this weekend, and I'll have time to mess with it so I can show photos of the Grinch brass compared to 6.5 Grendel, 6 RAT, 22 Grendel, and finally, 22 Grinch.