Manufactures of firearms, ammunition and other relevant products who have pledged support for the National Shooting Sports Foundation’s Rimfire Challenge are growing in numbers. The program, encouraging competitive .22 pistol and rifle shooting at all levels, from novice to veteran, has added Winchester Ammunition, Volquartsen Custom and Tandemkross as its most recently enlisted sponsors. Winchester Ammunition has committed “Silver Sponsorship” and has announced its participation in the challenge’s related Ammo Roundup Program, promising an allocation of 600,000 rounds of .22 ammunition. Volquartsen Custom has also committed to Silver Sponsorship. The company is a pioneer in the customization of the Ruger 10/22 rifle and today crafts some of the world’s finest rimfire rifles and handguns. New Hampshire-based firearm-parts manufacturer and supplier Tandemkross has come on board as a Bronze Sponsor of the Rimfire Challenge.