Can the barrel from Ruger's 77/17 fit 10/22WMR?  I don't know if 77/17's barrel is threaded in or locked in like the 10/22's.  The chamber might be a little too tight for a semi-auto, too.  But it would be nice to have a semi-auto for this hot little round.

BTW, what's that square hole doing on top of the rings on bench rest targets?

Although the barrels mount in a similar fashion, I don't think they will interchange. I could be wrong though.

That said, I would bet it would not be hard to have a barrel made to fit. Find a 'smith that specializes in .17 stuff. And if you wait several months barrels will likely be produced for this type of conversion.

The square is for sight in shots (unlimited number?) and the regular bull is for record. Or do I have it backwards?