The Ruger SP-101 series of revolvers are all manufactured from stainless steel, as well as featuring Ruger's patented safety transfer bar, attached directly to the trigger, to prevent accidental firing by preventing the hammer striking a cartridge without the trigger being pulled. The firing pin is located within the frame, a feature also common on Ruger revolvers since 1973.
A variety of barrel lengths were also produced, ranging from 2.25in (57mm) to 4in (102mm). Furthermore the SP-101 series has a variety of cylinders avaliable (dependent on the caliber used) starting from a five-shot cylinder (higher calibers), six-shot (mid-range calibers - some overlap with the five-shot cylinder calibers) or an eight-shot cylinder (.22 LR cartridges).
The SP-101 is also sold with either a spurred or spurless hammer. The spurless hammer signifies D.O.A. or Double Action Only.
As eluded to above the SP-101 series can shoot the following calibers:
- .22 Long Rifle*
- .32 H&R Magnum
- .327 Federal Magnum
- .357 Magnum**
- .38 Special
- 9x19mm Parabellum (discontinued)
.* Shot from either a six or eight-shot cylinder
.** Can be interchanged with any factory made .357 Magnum or .38 Special cartridges
The SP-101 is a series of revolvers. Hence rather than having individual names, a specific model is identified by its catalog model:
- KSP-221 - six-shot, adjustable sights, 2.25in barrel - discontinued
- KSP-240 - six-shot, adjustable sights, 4in barrel - discontinued
- KSP-241 - six-shot, adjustable sights, 4in barrel (34oz) - discontinued
- KSP-242-8 - eight-shot, adjustable sights, 4.2in barrel - Fiberoptic sights
.32 H&R MagnumEdit
- KSP-3231 - six-shot, adjustable sights, 3in barrel - discontinued
- KSP-3241 - six-shot, adjustable sights, 4in barrel - discontinued
.327 Federal MagnumEdit
- KSP-32731X - six-shot, adjustable sights, 3in barrel - Not avaliable on Ruger Website - Jan 2013
- KSP-821 - five-shot, fixed sights, 2.25in barrel
- KSP-821DOS - five-shot, fixed sights, 2.25in barrel - Bobbed hammer (Made, specifically, for US State Department)
- KSP-831 - five-shot, fixed sights, 3in barrel
- KSP-321X - five-shot, fixed sights, 2.25in barrel
- KSP-341X - five-shot, adjustable sights, 4.2in barrel - fiberoptic sights
- KSP-321X-CT - five-shot, fixed sights, 2.25in barrel - Crimson Trace Lasergrips
- KSP-321XL-LG - five-shot, fixed sights, 2.25in - Crimson Trace Lasergrips, D.A.O.
- KSP-331X - five-shot, fixed sights, 3in barrel
- KSP-321XL - five-shot, fixed sights, 2.25in - D.O.A.
- KSP-921 - five-shot, fixed sights, 2.25in - discontinued, Moon clips,
- KSP-931 - five-shot, fixed sights, 3in - discontinued, Moon clips
The SP-101, although many models have been discontinued, including all of those chambered to shoot the 9x19mm parabellum and .32 H&R Magnum, the SP-101 range remains in production. The basic .22 LR model was redesigned in 2011 after the production was stopped, temporarily in 2003.
The main use for the SP-101 is mainly produced for self-defence.