.38 Short Colt or .38 S&W in Police Positive?

[bkelleher01]

My father-in-law recently approached me with a Colt Police Positive, which appears to be of an early 1900's vintage. He knows that I am an avid shooter and reload all my own cartridges, so he asked if I could make up some loads for his CPP. He said that it is chambered for .38 Short Colt and gave me two or three of the last six rounds he had left for it, so that I could could examine COAL and bullet weight. In my travels, I have not been able to find anything to support the idea that either the Police Positive or the New Police were ever chambered in .38 Short Colt. They were chambered in .38S&W, which I understand to be a separate cartridge, despite the fact that many practice shooting .38 Short Colt in their .38 S&W revolvers against better judgement.


To further muddle the situation, I prematurely purchased some .38 Short Colt brass, but it is nearly .020" longer than the brass of the rounds that he gave me to examine, which are at least 30 years old and clearly marked "38 S Colt". Can anyone please advise as to what might be going on here? I'm tempted to place an order for some .38 S&W Brass and dies, but I don't know how much more money I want to throw at experimentation. Thank you in advance!


-B

 

[golden]

PROBABLY .38 Special

The gun is probably a .38 S&W or .38 Special. The easiest solution is to take the gun to a gun smith and have him measure the length of the chambers. You could do this if you could find a way of making a guage or finding a rod that is small enough to slide in the cylander and stop up against the front of the chamber. Then measure how long that distance is.

You can find the dimensions for the .38 S&W and .38 Special on handloading sights on the internet.

Jim

 

[rcmodel]

Colt Police Positive revolvers were chambered in .38 Colt New Police, which is identical to the .38 S&W cartridge except for the headstamp and FP bullet shape.
The S&W version used a RN bullet.

They were also chambered in 32-20 WCF and .38 Special.

I do not believe they were ever chambered in .38 Short Colt, however they could be used in it..

Duplicate post here.
http://www.thehighroad.org/showthread.php?p=8959310

rc

 

[dfariswheel]

There are TWO Colt Police Positives.

The Police Positive had a shorter frame and cylinder and was made for short cartridges like the .32 and .38 Colt New Police/S&W rounds.
The Police Positive .38 was made in the .38 Colt New Police/.38S&W and the .38 Colt Short.
The .38 Colt short is similar to the .38 New police and .38 S&W but the dimensions are different.

The Police Positive Special had a longer frame and cylinder and was made for longer cartridges like the .38 Special.

 

[Old Fuff]

The Colt Police Positive and Police Positive Special models were introduced in 1908. The two were identical in .38 caliber except the "Special" had a slightly longer frame and cylinder then the Police Positive.

The shorter Police Positive was chambered in .32 Colt New Police (same as .32 S&W Long) and .38 Colt New Police (same as .38 S&W). The only reason for the New Police name was that Colt didn't want to mark any of their products with something that had S&W in it.

On the other hand the longer Police Positive Special came in either .32-20 (.32 WCF) or .38 Special.

One interesting fact about the .38 Police Positive, which I believe is unique, is that the chamber throats and barrel groove diameters are identical to Colt's Police Positive Special's in .38 Special. This means that handloaders can use standard .38 Special bullets (.358" Dia.) rather then the usually specified .360" ones called for in other makes of revolvers chambered in .38 S&W. You do need to change the inside neck sizing plug to .358".

The .38 Short Colt dates back to the era of C&B-to-Cartridge Conversions, and I don't believe any Police Positive's were ever specifically chambered to use it.

 

[Kernel]

Not all "38's" are the same. Only the .38 Spl would have a bullet diameter of 0.357". The others (.38 Colts of various types, and the .38 S&W) should measure 0.361", the Colt Short 0.374".

 

[Old Fuff]

Nope: The little Colt is an exception to the rule.

Chamber throats = .3585"
Barrel Groove Diameter = .353" - .354"

These also match their specifications for .38 Special. Designed for soft lead bullets, Colt's .38 bores have always been tight.

The above was taken directly from a company blueprint.

 

[Dframe]

If you check the side of the barrel and find it is a PP rather than a PPS it's almost certain to be a 38 N.P. (same thing as 38 S&W) Look for a calibre designation on the barrel.

 

[Jim Watson]

Unless you are a proficient target shooter still using a revolver, I think the matter of bullet and barrel diameters is overstudied.

I loaded for three .38 S&Ws and a .38-44 S&W Target with .358" Special bullets and they did just fine for my purposes, which was CAS. Actually, the best single target I ever shot with the .38-44 was with some .356" 9mm bullets because I wanted to have a 146 grain (well, 145) factory equivalent.

 

[Old Fuff]

I have found that between various makes of .38 S&W chambered revolvers, chamber throat and bore dimensions can be all over the map. That said, the point I was trying to get across was that Colt Police Positive's, chambered in .38 Colt New Police (.38 S&W) have chamber throat and bore dimensions that are compatible with standard - and easly obtained - .358" bullets, and do not require harder-to-find .360" ones.

That said, one should experiment with different bullet diameters and powder charges to find what works best in their particular gun(s).