Some small Single Six (.22 and .32) guns aside, there have been two Ruger fixed sight models of the "cowboy" look (vs the adjustable sight Blackhawk models). The large frame Vaqueros were made in the 90s and through to 20_?_ - 'til about six-or so years ago anyway,...with the exception of some special "cleanup" runs since and sold through distributors such as Davidsons and Lipseys only. These were built on the "regular" Blackhawk frame, also referred to now by some as the "magnum-class frame." Since the Vaquero production officially ended, Ruger replaced it in 2005-2006 (?) with the New Vaquero, built on a slightly smaller frame that has commonly become known as the midframe. The New Vaquero shares the same basic frame as the recent .44 Special and 50th Anniversary .357 flattop Blackhawks. These guns very closely approximate the original Blackhawk frame size of the 1950s, and as an ode to requests cowboy action shooters (CAS), is also more "Colt like" in its dimensions than the "old" Vaquero.
Contrary to myth, the New Vaquero can take more than just "cowboy" loads, but can shoot "regular" off the shelf .45 Colt loads as well...but as JB says, not extra stout loads--otherwise referred to as "Ruger only" loads intended strictly for the Ruger magnum-class frames and Freedom Arms guns taking loads also so-designated.
Nothing at all wrong with the
New Vaquero, just not the .45 to get if you like to shoot heavy loads (ie, approaching/equaling or exceeding typical .44 Magnum levels).