Rimfire

Gunsmoke Engineering - Ruger 10/22 parts, accessories, reference shelf, complete rifles, and gunsmith services.
http://www.gunsmoke.com/

Sportables - Ruger 10/22 and MKII parts, accessories, complete custom rifles, complete custom handguns, and shooters chat room.
http://www.sportables.com/

Centra UK - Rearsights, foresights and filters to enhance a shooters sight picture and reduce group sizes. Aimed at target shooters.
http://www.centra-uk.co.uk

The Sight Ruger 10/22 Rifle Site - Many resources for the Ruger 10/22 including diagrams, accessories, how-to articles on upgrades and maintenance, accessory reviews and links to related sites.
http://www.ruger1022.com/

Eley, Ltd. - Manufacturers ammunition in .22LR and .22 short calibers. UK Based.
http://www.eley.co.uk/

Rockin' Rimfires - Military copy and paramilitary style rifles chambered in .22LR. Photographs, information, message board, sources, and contact information.
http://mem.tcon.net/users/5010/5491/rimfires.htm

Eric Brooks - Resources include a CZ 452 FAQ and downloadable targets in addition to CZ 452 accessories.
http://cz452.com/

CMP Mossberg US 44 FAQ - Resources related to the Mossberg 44US distributed by the Civilian Marksmanship Program including FAQ, history, common problems and solutions, and links.
http://www.cobs.com/lprgc/m44faq.htm

RimfireCentral.Com - Open discussions to help the hunters, plinkers, target benchrest shooters and the hobbyist, and to make friends on the way to further our sport.
http://www.rimfirecentral.com/

New York State Rifle and Pistol Association - Includes rules, contacts, teams, and schedules. Sporterifle is a postal competition league for sporter class 22s.
http://www.sporterifle.org/

Patria Lapua Oy - Manufacturer of high quality .22 rimfire ammunition.
http://www.lapua.com/