Hello. I've got a problem with my Colt Diamondback in .22lr. She is an 'end of the run' model based on the serial number. The fit and finish are superb but the dang thing just doesn't shoot. I've tried a whole mess of different ammo. I've had really experienced shooters try it and the conclusion is that the bugger doesn't shoot as the best we can do off a rest at 20 yards is about 4". Is there anything I can do to improve the accuracy of the pistol or should I take the loss and trade it off for a S&W 617?
.22lr Colt Diamondback question
- Thread starter jacho
- Start date
Seven High
New member
Check to see if the barrel is leaded up.
Dfariswheel
New member
Shoot as good a group as the gun is capable of, preferably shooting off sandbags for maximum accuracy.
Write the details on the target: Ammo used, range shot at, etc.
Wrap up the gun and test target, and send in to the Colt factory.
It might help if you enclosed several targets, all shot at the same range, with different brands of ammo.
They'll figure out what's wrong and fix it.
Could be any one of a number of things.
No one can diagnose this kind of problem without actually seeing the gun, and certainly not over the internet.
Write the details on the target: Ammo used, range shot at, etc.
Wrap up the gun and test target, and send in to the Colt factory.
It might help if you enclosed several targets, all shot at the same range, with different brands of ammo.
They'll figure out what's wrong and fix it.
Could be any one of a number of things.
No one can diagnose this kind of problem without actually seeing the gun, and certainly not over the internet.
I believe I read once that the cylinder chambers on some were cut closer to 22wrm dimensions (which are slightly larger than 22lr specs). This resulted in some shooting okay and others not.. depending on ammo. You can easily measure the chamber mouths on your gun to verify this though I don't remember the specs off the top of my head. You could try different ammo and see if will shoot better.
Dfariswheel, good advice. The groups were shot off sandbags but I was so disappointed I didn't save any of the targets. Easily enough to go shoot some more targets. I guess I should also mention that I live in the 'Republic of Canada'. It would be very difficult for me to send the gun across the border to Colt in Hartford, but I will contact them to see what options may be available to me. 
laytonj1, I've heard that the 'end of the run' models of the Diamondback were a hit and miss. I didn't research the serial number enough when I made my purchase. See the list below, mine has an 'AAxxxx' serial number, hence my comment about it being an 'end of the run' model.
Colt Diamondback
Year Serial Number
1966 D1001
1967 D2600
1968 D14400
1969 D26500
1970 D38450
1971 D45551
1972 D51400
1973 D55401
1974 D59801
1975 D60251
1976 D72251-D99999
1976 N01001-N01800
1977 N01801-N15674
1978 R13901
1979-1981 Sxxxxx
1982-1983 Pxxxxx
1984-1986 Aaxxxxx
laytonj1, I've heard that the 'end of the run' models of the Diamondback were a hit and miss. I didn't research the serial number enough when I made my purchase. See the list below, mine has an 'AAxxxx' serial number, hence my comment about it being an 'end of the run' model.
Colt Diamondback
Year Serial Number
1966 D1001
1967 D2600
1968 D14400
1969 D26500
1970 D38450
1971 D45551
1972 D51400
1973 D55401
1974 D59801
1975 D60251
1976 D72251-D99999
1976 N01001-N01800
1977 N01801-N15674
1978 R13901
1979-1981 Sxxxxx
1982-1983 Pxxxxx
1984-1986 Aaxxxxx
Person of Interest
New member
Have you tried a variety of ammo? Some 22s are famous for preferring one brand over others.
Then I would check the forcing cone. I have heard of revolvers being shipped with no forcing cones cut at all. A smith might polish or re-cut the cone.
Then measure the chamber mouths and indexing. Cylinder might be faulty with oversized or misaligned chambers.
Then I would check the forcing cone. I have heard of revolvers being shipped with no forcing cones cut at all. A smith might polish or re-cut the cone.
Then measure the chamber mouths and indexing. Cylinder might be faulty with oversized or misaligned chambers.