.30 WCF is usually an abbreviation for .30 Winchester Center Fire a.k.a. .30-30 Winchester. The most common guns in this caliber are the Winchester Model 94 and Marlin 336 lever actions, but a wide variety of rifles and handguns have been made in .30-30 over the years. A picture, or at least a more detailed description, would be necessary to identify your firearm.
Smith, and Wesson, and Me. -H. Callahan
Well waddaya know, one buwwet weft! -E. Fudd
All bad precedents begin as justifiable measures. -J. Caesar