I knew they played about with various training conversions for the black rifles using original barrels - These type of conversions have been going on for about as long as the .22rf has been about, Morris tubes in Martini Henrys and .455 Enfield revolvers and such. I also see they do a 1in15 barrel for the Thompson Contender and something new I learned is that Anschutz use a 1in14 barrel in there biathlon rifle for use in cold weather.
I was thinking more in the terms of searching for pure accuracy. There's no getting away from it, no matter how much you spend on a .22 rifle, super match quality, shot from a bench in a tunnel range, it wont compete with an accurate centrefire.
Why is this? It's the ammunition surely. You would think, if you buy a top of the range rifle and top of the range ammunition, say an Anschutz and Eley tenex you would get the best accuracy - not so though, to get the best accuracy you will need to take your rifle to Eley and they will try numerous batches of tenex in your rifle to see which one performs best, then you buy a wad of that batch. That tells me, even with the best quality control there are variables that shouldn't be there.
With a centrefire benchrest rifle a great deal of effort goes into case/load preparation and development and it's tuned to the rifle - Most of the really great cartridges, 6ppc, 6br, 220 swift, 257 Roberts etc. were developed as wildcats by dedicated home loaders, which in turn drove the manufacturers to keep up. Unfortunately it's not so simple with the rimfire case - We make this ammunition because it's cheap to make and you guys will have to make a rifle that shoots it.
I agree that Anshutz were making match rifles with 1moa accuracy in the 1960's, but they really don't shoot any better now, whereas in the 1960's, a centrefire rifle with 1moa was considered a benchmark for accuracy now it's very "run of the mill" - Centrefire accuracy has moved on in the last 50 years, 22lr accuracy has hardly moved at all. All major .22 ammunition manufacturers must run research and development programs, what have they been doing for the last 50 years? Ahh yes, they've changed the shape of the nose slightly on Eley tenex and match.