Jesse,
I did the counterbored muzzle on the Krieger I used on my Stiller 2500XR repeater that you & I talked about here while you were working out the extraction/ejection issues you were having with your Stiller. That was the 1st 22RF bbl I'd fitted & chambered after several years of doing CF bbls. To be honest, I wish I'd have tested it for accuracy before & after doing the counterbore, if for no other reason than to have an opinion based on experience. But the rifle shot pretty darned good, so it never occurred to me that the counterbore might've caused an issue. Call it blind faith in what Anschutz's NA Custom Shop does - I never questioned the theory behind their practice. I do believe that I finished that Krieger about .600" longer than the 22" I specified when I ordered it, as that's the approx. length of the SWR tenon for the Spectre II, and did much the same with the Benchmark & Lilja bbls that I did for the CMP 40X & 40XB jelrod-converted repeaters after I'd sold the Stiller. Krieger says it doesn't matter much where you finish their 22RF bbls, because they lap the taper from start to finish (or at least that's what I got out of a conversation with them while ordering a couple more 22RF blanks from them after doing this first one). Benchmark & Lilja both told me that finishing their barrels shorter than the ordered finish length would void the accuracy warranty, so I made sure I finished them the same .600" longer so the counterbore would be just beyond the lapped-in choke. But again, I never considered testing them before & after doing the counterbore. I'm not quite curious enough about the effect on accuracy of the counterbore to cut off the .400" thread tenon I did on the V-22's Krieger for the TBAC 22TD I use on it - it often shoots slightly better groups than either of the 40Xs. But you raise a valid point, and it's got me wondering if any of the five 22RF bbl's I've finished would have shot better before I did the counterbore.