Next week I begin another travel series — 54 days at sea on a trip that took us on two transatlantic crossings and a tour of both the Mediterranean and Black Seas. But for this week I’m returning to the subject that garners my highest audience, firearms.
It’s not often you come across a 36-year-old firearm in this condition. And according to the previous owner, the original Colt MK IV Series 70 has less than 100 rounds through it.
There are a few flaws in the original Colt satin blue finish, but I’d rate this pistol at around 98%. The wood grips also had some minor dings, as well, but also very minor.
If you read my previous blog article on the new MK IV Series 70 (see: A Look at the Colt MK IV Series 70), then you know that the originals differed from the original in more than just the trigger. The original run from 1970 to 1983 also included a fingered “collet” bushing over a barrel with a widened muzzle end. This change was incorporated to improve the barrel-to-bushing fit in order to improve accuracy.
The collet bushing held over into the Series 80 line until the late 1980s, but reports of bushing failures led Colt to revert back to the solid bushing which carries over to the reintroduced Series 70 pistols of today.
The example here has a 70B prefixed serial number. That places this 1911 at the very end of the original MK IV Series 70 run, as the 70B serial number began in 1981 and ran through the end of production in 1983. The rest of the serial number leads me to believe that the actual year of production was probably 1982.
In my second article on the current Series 70 (see: Colt’s Series 70 Trigger Put to the Test — Series 70 vs. Series 80) I noted that the trigger was not all it was cracked up to be my Colt 1911 enthusiasts. I’ve since repeated my experiment (see video below) on side-by-side comparisons between probably half a dozen new Series 70 Colts and the current line of Series 80. Results were always the same. Out of the box, the current Colt Series 80 routinely beats the current Series 70 on every gun I’ve tried.
So, what about the original MK IV Series 70? Not so in this case. This truly the trigger I’ve seen praised. That’s not to say that the current Series 70 trigger is bad, as no Colt 1911/1991A1 trigger can be described as such from my experience, it’s just that the new Series 70 has more creep after take up and displays a degree of grittiness that simply doesn’t exist in any other Series 80 Colt I’ve tried.
Sights on the original Series 70 match the current crop. They’re nothing about which to write home. I much prefer the three-dot sights Colt uses on the current Series 80.
Here’s a comparison between a new Series 70 and a Series 80 M1991A1 to illistrate what I mean:

New MK IV Series 70 left; new M1991A1 Series 80 right
Fortunately, both the original and previous owners of this pistol did something that far too few people do; they retained the original box and owner’s manual.
Here is this original Mk IV Series 70 posing with the box it came in:
But the box has definitely seen better days, and the Styrofoam insert inside was partially melted away from gun lubricant. Fortunately, that didn’t mar the finish on the pistol.