There was no MKIV (4). They were just Troopers, then MK3, then MK5.
The original Trooper is a great gun, based on the E/I frame same as the Python but without the same level of inside or outside polishing or fancy barrel.
The MK3, however, well.............if you really want to be talked out of it......
Not a fan of the MK3. They used sintered metal hammers and triggers at a time before the tech was mature, and they can be somewhat brittle. Ive seen multiple broken triggers- they snap where the metal is thinnest around the pivot pin. In the one case, the gun would still shoot, but there was a noticable and unusual clicking sound as the trigger was pulled- only a small section had broken away. God only knows how many rounds the gun had through it before or after the breakage....
In the other case, half of the loop had broken off and the trigger was nonfunctional.
Granted, this is probably a rare occurrence considering the thousands of MK3s Colt churned out, but its a thing. Jack First was making billet replacement parts for them- the fact that they saw a market says something- but they were $$$ and I dont know if they still have any stock remaining or plan to do another run anytime soon.
When the Mk5s came around, they ditched the sintered parts and went with regular castings- never seen an issue with these. Trooper Mk5s were only produced for a few years and are rare- they kinda evolved into the King Cobra and (scaled up) Anaconda.
Its a shame, too, because I consider the Trooper MK3 one of the best looking Colt revolvers ever, but they are a hard pass for me. YMMV, of course.
If its an original, 1st Gen Trooper, I say buy. I did.
