Mark IV designation

[44 Man]

Ok old timers, I don't have an answer for this one. When the 'Mark IV's came out, I always assumed they designated a series 70 gun with the finger bushing, that was all of Colt's hype in their advertising at the time. Then Colt got rid of the finger bushing. Then came the series 80's parts, still marked as 'Mark IV'. Now I know the 'Mark IV's designation a little nicer finished gun than the 1991 series. And my new Defender is just marked with the name 'Defender' and '90 series' on the slide. Now I understand all about series 70 and 80 parts, all the 90 parts seem to be the same as the 80 series parts, excepting maybe minor changes on the hammer and sear surfaces. So what is a 'Mark IV' gun supposed to represent in Colt's thinking nowdays?

[191145]

And where did they get 'Mark IV' anyway? Usually this would indicate the fourth revision in a model series. So, there was the Model of 1911 commercial model, then the M1911A1 commercial model, then the Mk IV Series 70 - that's three, not four.

[Hawkmoon]

The defunct Colt Pony .380 and Pocket Nine double action pistols were also Series 90s. I think that only indicates that they were forst introduced during that decade.

[Hunter]

From what I understand the MK IV was a designation of the timeline the pistol was introduced. The Series 70 MK IV being from 1970 to 1983 and the MK IV Series 80 introduced in 1983. I have seen several Series 90 that were double action but like you said the Series 90 also includes the Defender which is single action.

[dakota1911]

I don't know if this is where the MK designation came from, but if you have a copy or can check out a copy of Charles W. Clawson's book, "Colt .45 Government Models (Commercial Series), 2nd Edition 1912 through 1970" then look around page 100 at the Cold Gold Cup National Match. It talks about .38 Special N.M.'s and versions being MKII and MKIII (no MK number on the first one although Clawson calls it a Mark I).

At least I always thought this is where MKIV roll marks came from and Series 70 is obvious

[Hunter]

I do believe the MKIII Colt Gold Cup National Match Mid Range (.38 Special like you said) were manufactured from 1961 to 1974 which would also follow the timeline from MKIII to MK IV. I am speculating though.