I can still cock the gun with my thumb and shoot it SA if I want. I don't understand the logic. I would like it explained to me.
Sure thing.
The
total Fitz conversion with all of its features was supposed to result in a revolver that could be
quickly employed and brought into action in a close distance emergency. This is not a situation where it's likely one would need or use the single-action option. The hammer was bobbed because of the presumed use of side pocket carry, or in any case concealed under some kind of garment where a conventional hammer spur could get snagged. However, as Sam pointed out, cocking a bobbed hammer is more difficult - especially under stress or in a hurry - then with the hammer spur intact, and can (and has) led to an unintentional discharge. I personally know of two such instances, and neither would have happened if the revolver and been modified to double-action-only.
While the Fitz Special snubby is well known, many are unaware that Colt and others somestimes made a
partial conversion, where some features were included, but not all. Perhaps the best known was Col. Askins', Colt New Service .38 Special that had a 4" barrel, King custom rib and sights, and a cut-away trigger guard - but no changes to the hammer or rounding of the butt. It was carried in a regular Border Patrol holster of the kind issued issued at the tme.
In the hands of a competent and practiced double-action shooter the Fitz was an effective weapon at distances up to - and sometimes further - then 50 yards. This was much more then the designer intended, and brings the need of a single-action option into question, especially when it adds unnecessary risk.
The Fitz Special was not intended to be any kind of general service or target gun. It was and is, a special purpose weapon and nothing else.