Q: What's the procedure for replacing a barrel on a revolver? It's a Colt Police Positive in .38 special.
What a source for getting a barrel?
Any input is greatly appreciated.
Sportsmans guide had a few a while back. Gun Parts Corps has some as well. All the "D" frames have the same threads and use the same barrels with different roll marks, so a Police Positive Special will accept a Detective Special, Viper, Cobra, Agent, etc. barrel. A Diamond Back barrel would work, but the sight profile may be different. I'd stay away from using one of those.
I've read about how to rebarrel a revolver, but that was long ago and I've forgotten most of it. I've never needed to do one in the past. Were you going to a different barrel length or caliber or is it just screwed up?
Ross, thanks for the input. The bbl in question is just messed up and needs to be replaced.
Unfortunately, replacing a revolver barrel is not a job that can be done at home. Not unless you're willing to make a HEAVY investment in tooling, and the time to learn how to use it properly.
A revolver barrel IS NOT simply a threaded pipe that can be screwed on the frame. It must be fitted, and the fitting is absolutely critical.
The procedure, (in brief) is:
A special barrel vise is used to hold the barrel, and a special gun model-specific action wrench is used to unscrew the frame from the barrel. (Both expensive)
A new barrel is checked to insure it will fit properly, (used barrels ARE NOT always fittable, or usable).
The new barrel is test fitted to the frame, and a lathe is then used to remove an EXACT amount of metal from the barrel shoulder to bring the front sight to top-dead-center, when the barrel is torqued into place. (Lathe: VERY expensive, and absolutely necessary).
The barrel is properly torqued to a "crush fit" against the frame shoulder, with the front sight at top-dead-center, using the barrel vise and action wrench.
A special tool (expensive) is used to establish the barrel/cylinder gap, (critical), by cutting the rear of the barrel. This MUST be 100% SQUARE to the front of the cylinder. A hand file won't do it.
The barrel/cylinder gap MUST be correct. Too small a gap, binding of the cylinder. Too large a gap, inaccuracy, and spitting lead.
The gap is measured in the thousandths, with a very fine line between too much and not enough.
A special tool, (expensive) is used to cut the forcing cone in the barrel. The forcing cone MUST be cut to an EXACT angle AND mouth diameter. If not properly done, the gun will be inaccurate and will spit lead badly.
The old time instruction to "whittle some barrel blocks for the barrel, stick a hammer handle or 2 X 4 through the frame, and twist her off", is pretty well guaranteed to ruin the gun.
Revolver frames WILL bend and break though the barrel ring if done this way. Not all the time, just most of the time.
You still find people who do this, supposedly with good results, but they ain't gonna be standing by to buy you a new revolver if things don't work out like they say.
In short, revolver barrel work is a gunsmith-ONLY job. If you want to learn more, and decide if you'd like to do this as a hobby, buy a copy of Jerry Kuhnhausen's book "The Colt Double Action Revolver: A Shop Manual, Vol. One"
This has a very complete set of instructions on how to do barrel work, and an explanation on why doing it the hammer handle way has ruined so many fine Colt's.
Damn fine read Farris,knowledgable and to the point!
Thanks. I used to get paid for doing it.