Other than the Python, the "D" frame Colt Detective Special and Cobra was the last of the old style action Colt revolvers.
Needing a cheaper to make small revolver to stay competitive, Colt designed a new gun, loosely based on the modern transfer-bar action they pioneered with the Trooper Mark III.
This new gun was built on a frame Colt named the "SF" or Small Frame.
This new gun used a transfer-bar safety system, a cylinder locking bolt system similar to the Trooper Mark III/King Cobra guns, but still used the same flat "Vee" spring from the Detective Special.
In this system, the "Vee" spring's lower leg did not power the trigger mechanism like on the "D" frame guns, it just rested on the frame to provide tension.
It was clearly Colt's intention to make this new Small Frame the basis for a whole range of revolvers.
There were rumors that Colt was considering a Diamondback-like revolver in .22 LR, as well as defense revolvers in a variety of calibers and barrel lengths.
The new gun was catchingly named the Colt SF-VI, or Colt Small Frame-Six Shot.
The reason for the odd name was to prevent confusion with the Detective Special, which was still in the Wholesaler-Dealer pipeline.
As soon as the last of the Detective Specials were sold, Colt renamed the gun as the Colt DS-II, or Detective Special Two.
Colt made small runs of limited production models of the DS-II, including a "Special Lady" polished and "hammerless" model for women, a few 3" barreled DS-II's, and a VERY few 4" barreled versions.
Colt soon brought the gun out in .357 Magnum, and called this version, the Colt Magnum Carry.
Shortly after introducing the Magnum Carry, Colt made the decision to drop most revolver production, and along with the King Cobra, the "SF" framed guns were discontinued.
The early SF-VI model had probably the lightest double action trigger ever on a revolver.
The pull was so light, some users had problems with the trigger failing to reset.
Mid-production SF-VI's had a notice in the owner's manual, that if the user had problems, Colt would install a heavier trigger return spring, free of charge.
The SF guns had a mixed reception.
Many people were disappointed, having believed we were finally going to get an old style Detective Special in stainless, not a totally different design.
There were a number of design features on the SF guns that were specifically to reduce production costs.
The end of the barrel was deeply counter sunk, and the outer muzzle was left squared off.
The muzzle edges were so sharp, it was possible to actually get cut, and holsters got damaged quickly by the sharp edges.
The rear sight no longer had a "shadow box" cut at the rear, and the top strap and rear sight weren't bead blasted to a dull finish.
This left the sight with a shiny finish that made sighting difficult.
The ejection rod was coarsely knurled on the end, and had no ejection rod head.
This small diameter, headless rod would be uncomfortable to use if you had sticky cases.
One area of concern was the cylinder locking bolt.
When the trigger was pulled, the bolt unlocked, then dropped back onto the cylinder so quickly, that the cylinder had hardly begun to rotate.
I was concerned that even minor wear to the bolt would cause the action to get out of time, and fail to unlock at all.
On the plus side, the SF guns were VERY sturdy, held a full six shots, and were nearly as accurate as the older "D" framed guns.
Trigger action was light and very smooth.
Although the short front sight design appears strange to those used to the older shrouded Colt Detective Special, it gave an excellent sight picture.
I did some modifications to my early SF-VI.
I altered the muzzle contour to that of the shrouded Detective Special, eliminating the sharp edges.
I cut a "shadow box" recess in the rear sight notch to provide a non-glare sight picture, and bead blasted the top strap and rear sight area.
I built and installed a ejector rod head, and opened up the rod recess in the barrel shroud to match the older Detective Special.
As a successor to the "D" frame Colt's the "SF" framed guns may have disappointed older Colt owners, but they were an excellent value for the money and quite popular to those who bought them.
Other than some quality control problems with accuracy on a few guns, these were excellent pistols that were prime CCW guns.
It's a shame Colt had to discontinue the "SF" series, and it looks like it will stay discontinued, as Colt has pretty well said that the "SF" will never be made again.
Due to the low production numbers, and the limited numbers produced, the "SF" guns are being actively hunted by collectors.
The prime collectibles are the limited production versions like the Special Lady, the introduction versions, and the odd barrel length 3" and 4" versions.
In addition, smart shooters are hunting for these for CCW guns, especially the Magnum Carry.
As in all Colt's, and especially in limited production models, prices are going UP and FAST.
Due to collector and shooter interest, these models are coming on the marker rarely, and quickly disappear into collections or holsters when they do.
A smart shopper will grab these "SF" guns whenever the price is reasonable, and hold them for the usual skyrocketing of the price Colt's have.
