I purchased my first revolver in Jan of 1971 for duty use at a local gun shop we were taken to, to buy all our duty gear (If you did not own one that qualified).
Some got Pythons or Smiths, but I ended up with a Colt Trooper, they were out of Pythons when I stepped up to the counter, but I didn't know the difference anyway.
When I got off probation in 1972, I bought a 6 1/2" model 29-2 S&W, blue, in the wood display case. Carried it until 1976, then switched to a 4" S&W Nickel, model 58, 41 mag. Had that modified by a local gunsmith to accept S&W target sights. Carried that until 1985 when I switched to a 1911. The 58 & a revolver duty rig were always in my trunk, as you surrendered your gun to Det's after a shooting. Always nice to have another duty gun handy on the scene. Always qualified with several guns.
Always carried a back up gun, usually a S&W snubby, but I went thru a collection of smaller guns looking for one that was just right...including Colt Det Special, Detonics Combat Master, Ruger GS 32 (357 mag)fixed sight (This one stayed under my console, where it could be reached - Issued patrol cars were made easy to modify to your needs).
When assigned to Special Ops (plain clothes) in 86, I switched to a Detonics Scoremaster in .45 acp.
Years later, back in Uniform as a SGT, I switched to a Para P-14 .45 acp {14 rd).
Went back to Special Ops as SGT (plain clothes) for 3 years, then back to uniform in about 2000.
Went to the Traffic Division until I retired in 2003.
Saved almost everything, except the Trooper (sold to a city cop) & the Model 29 (which went to a friend in need).