I too am shooting a Super 14 Match Grade .22 LR Contender with a 3x12x BUrris LER Fine Plex-PA Handgun Scope (mostly on 10x). While I have not had the opportunity to do any shootin outdoors with my Barrel (yet), I have been shooting Indoor Bench Rest with it all winter at our local club. The target we use is the USBR Target.
On this target the "10 Ring" measures .10". To score a "10" the bullet just needs to touch the "10 Ring" (Inward Scoring). However to get an "X" the bullet needs to be fairly well center so that no portion of the "10 Ring" is visible. I have been scoring between 247 & 250 on this target (with a possible score of 250-25x), with the X count normally running around 8 to 10.
In addition to shooting this at our local club, I also participate in an E-Mail Bench Rest Match every month that is sponsored by a Rimfire Talk Forum. This keeps me shootin all year long, but does get kind of hard on the ammo supply.
About the only modification I have done to my barrel is to do a little polishing with FLITZ Bore Polish, and Free Float the Forend. In addition to sanding out the barrel channel of the forend I also glued in a couple of metal washers in the bottom of the countersunk holes in the forend to serve as pillars. While the scores have not gone up, the x count has a little, and I don't seem to get as many unexplained fliers.
Get out and shoot that .22 LR barrel, and have fun. I have shot Contenders for over 20 years and this is the very first Rimfire Barrel I have ever had for a Contender. The biggest mystery is why it took me so long to get one. They are a true joy to shoot, inexpensive and very accurate.
Have fun, and good shootin.
Larry