I've been following this thread for a while and there are some very good points being made here as I see it.
First post that really catches my attention is David Valdina's post #46. To me, as a long time shooter with both military experience and a serious interest in precision shooting, I have been following the development of high accuracy semi-automatic sniper rifles by the military and I think a rimfire semi-auto of very high accuracy is possible. I do not know if the semi-auto sniper rifles have reached the stage of development for use yet however some of the test results I have seen are amazing and definitely prove the the technology exists for a precision made semi-automatic rifle capable of competing in the 25 and 50 yard rimfire matches that we shoot...
I also believe of what hardware is available today, it most likely will be a gun of the basic 10-22 design that has the best chance of accomplishing this. Mainly because of the third party components that are available to accomplish this. Picher, in post #48 brings up the matter of the aluminum receiver and the method of mounting the barrel in a 10-22 being a weak point when looking at the goal of building a high accuracy rifle, however there are two companies that now offer a CNC machined stainless receiver for the 10-22 as well as the possibility of having a threaded receiver and barrel which eliminates these weaknesses from the basic 10-22 design.
I believe it was Nipper who mentions using a pressure pad to support the barrel, and this is also a proven technology that can be used to fine tune the barrel very effectively. I can support this claim with a Model 52D Winchester that I have been shooting for years that Winchester includes a barrel pressure/support tuning device close to the end of the forearm in the manufacturing of this fine rifle, and this 52D rifle today still outshoots both Anschutz and Cooper target rifles that I own and shoot.
So, yes, I think that given the right components and gun smithing skills to put together a semi-automatic rimfire rifle capable of being competitive in rimfire BR shooting is very possible.
I'd like to make a suggestion, what we need is several of the companies involved in 10-22 third part components and or private individuals with an interest that can afford, to put together a cash award, say something like $10,000 or more if possible, to the first individual to win a major match using a rimfire semi-automatic rifle. This award could be prorated something on the order of $1000 for any winning target at 50 yards in an official match, $5000 for any clean target shot, and $10,000 to the first person shooting a top aggregate score in any official state or national match...
I think if something along this idea of an award could be put together, you'd start to see some amazing customized semi-automatic rimfire rifles capable of an even higher level of accuracy start to appear...
By the way, I am an old school shooter, all my competitive rifles are single shot bolt action guns, I do own one semi-automatic rimfire rifle, a Marlin Model 60, so no favoritism here, just a vision of what I think is possible...
Happy Shooting, Y'all...
Mitch & Shadow...