I bought two CM straight 1.20" dia, 27" long 22RF blanks from Green Mountain about 2yrs ago. I intended to use the taper attachment that came with a Precision Matthews 14x40 lathe to contour them, but that turned out not to be a practical route, so they just sat in the shop for a year or so. Then I decided I wanted to try to get some use out of them, and so sent them to John Scandale at Keystone Accuracy to have him profile them on his CNC lathe. We went with his Palma sport contour, which is almost as heavy as a M24. I had him do the Rim-X tenon on one, and to finish it at 24" with a 11* crown. I had him leave the other one as it finished in the Palma sport contour. They came back in a timely fashion, just as I'd specified.
I chambered the one he'd semi-finished with my EPS reamer, but had problems that I felt were due to the chamber being a bit too tight for reliable feeding in the Rim-X, as it was knocking loaded rounds out of engagement with the extractor as they were being fed, causing jams. Perhaps doing a little more radical radius work on the chamber mouth would've fixed it, but instead, ran a JGS carbide 52D reamer into the existing EPS chamber. The 52D is .003" larger at the rear, and shorter than the EPS, so it didn't touch the leade of the EPS chamber. It fixed the feeding issue, but accuracy wasn't acceptable. I had a phone conversation with Ray at Zermatt, and he suggested that, if I had enough shank length to do it, to part-off the entire chamber and start over again with the 52D reamer from the start. I did that, and the feeding was still fine, and accuracy did improve a good bit - though it's still not on par with any of the four V22 repeaters I have. Three of them have EPS chambers cut in Krieger blanks with the same reamer I originally used on the GM for the Rim-X, while the other one was purchased as a bbl'd action directly from VGW, with a 22" Kukri Bartlein, so it has the Ravage chamber, and is at least as accurate as the other three with EPS chambers. Padom has mentioned that some of his other GM bbls needed to have a few hundred rounds run through them before they started shooting really well, and I'm pretty sure I haven't put more than 100-150rds through the GM I'm talking about.
So after reading Padom's reviews of the Rim-X pre-fits he's gotten from Mike at Manzella Precision, I decided to send the remaining contoured GM blank to Mike and have him chamber it with Padom's reamer, and finish it at 24". While I'm waiting on that bbl to come back, I'm wanting to put another few hundred rounds through the GM with the 52D chamber that's on the Rim-X. Just need a day when it's not 100*+ outside, then I could put some known good SK Std+ & Rifle Match through it, along with all three lots of the old Federal GM UM22 (re-branded RWS), and finally, some of the R50 I have. If it's not too blessed hot, and I have a little more patience than I usually do, I might wipe the bore with a couple of wet patches then dry patch, between brands. I use Ed's Red, which isn't a real aggressive solvent. I owe it to the GM bbl that's on the rifle, plus I really want a valid comparison between the two GM bbls & the 52D & Eachus chambers. The guy who was running the fun PRS-style matches at a club 170mi from here has stopped holding those matches, and if nothing else, this Rim-X/Green Mountain comparison will give me an excuse to do some extensive shooting...