There are two versions of the Rowel hammer SP101 - Single Action / Double Action (SA/DA) and Double Action Only (DAO).
"Rowel" is defined by Webster:
www.merriam-webster.com
It was first suggested in an engineering drawing dated 7-21-1986. It has the same profile as the rowel hammer used in the "P" series autos. The first "P" auto, the P-85, was to be in production in 1985. The earliest SP101s were shipped in late 1988. Thank you, Don, for the photo.
According to MASSAD AYOOB, the "early "rowel" hammer was championed by the late Ruger exec Steve Vogel,"
gunsmagazine.com
Even though it seems very practical for a concealed carry gun, it was not adopted. Only a very few (maybe a dozen or two?) were made in the SA/DA mode.
I can speculate that Bill Ruger was a bit of a traditionalist and preferred the original spur hammer. Bill Ruger did have a great marketing sense with very few marketing misses. With close to 1 million SP101s made, one would be hard to disagree with Bill's choices.
The DAO rowel hammer was used on a special run for a U.S. state's Dept. of State. (Not the central government, The U.S. Dept. of State.) We have yet to identify which state's Dept. of State. New Jersey is at the top of the speculative list.
While it seems odd to put a spur or rowel on a DAO (double action only) revolver that cannot be thumb cocked for single action, I can further speculate the government bid required a DAO revolver to be carried in a holster with a hammer retaining strap. I would be grateful for any clarifications.
I have acquired one of each.
The top gun is the very rare SA/DA, and the bottom is the Dept. of State DAO.
Terry T
"Rowel" is defined by Webster:
![www.merriam-webster.com](/proxy.php?image=https%3A%2F%2Fmerriam-webster.com%2Fassets%2Fmw%2Fstatic%2Fsocial-media-share%2Fmw-logo-245x245%401x.png&hash=643b2cd78d2c28538698e8c20a2bb3c6&return_error=1)
Definition of ROWEL
a revolving disk with sharp marginal points at the end of a spur… See the full definition
It was first suggested in an engineering drawing dated 7-21-1986. It has the same profile as the rowel hammer used in the "P" series autos. The first "P" auto, the P-85, was to be in production in 1985. The earliest SP101s were shipped in late 1988. Thank you, Don, for the photo.
According to MASSAD AYOOB, the "early "rowel" hammer was championed by the late Ruger exec Steve Vogel,"
![gunsmagazine.com](/proxy.php?image=https%3A%2F%2Fgunsmagazine.com%2Fwp-content%2Fuploads%2F2022%2F05%2FG0807-Ruger-556.jpg&hash=b1203126be2390595c7153a29b006490&return_error=1)
THE REDOUBTABLE RUGER SP101
Unusually rugged for its size, this accurate revolver is a favorite among serious shooters and pistol-packers.
![gunsmagazine.com](/proxy.php?image=https%3A%2F%2Fgunsmagazine.com%2Ffavicon-32x32.png&hash=ce80511995b8577f07cac2bb2253e5f5&return_error=1)
Even though it seems very practical for a concealed carry gun, it was not adopted. Only a very few (maybe a dozen or two?) were made in the SA/DA mode.
I can speculate that Bill Ruger was a bit of a traditionalist and preferred the original spur hammer. Bill Ruger did have a great marketing sense with very few marketing misses. With close to 1 million SP101s made, one would be hard to disagree with Bill's choices.
The DAO rowel hammer was used on a special run for a U.S. state's Dept. of State. (Not the central government, The U.S. Dept. of State.) We have yet to identify which state's Dept. of State. New Jersey is at the top of the speculative list.
While it seems odd to put a spur or rowel on a DAO (double action only) revolver that cannot be thumb cocked for single action, I can further speculate the government bid required a DAO revolver to be carried in a holster with a hammer retaining strap. I would be grateful for any clarifications.
I have acquired one of each.
The top gun is the very rare SA/DA, and the bottom is the Dept. of State DAO.
Terry T