We test loads for CAS guns.
Last month we converted a Pietta reproduction of a 51 Colt Navy revolver. We spent a little time at the range working up some loads for this gun and for our .45 Colt reproductions. We feel that any of these loads would be acceptable for use on this month's 58 Remington reproduction that we converted to .45 Long Colt.
The 51 Navy
We began by working up loads for the 51 Navy revolver using a Rapine .358 inch diameter 149 grain single cavity round nose flat point hollow base bullet mould. We would like to have used a much lighter bullet, or perhaps a hollow base wadcutter, but we were not able to locate a mould for such a bullet.
A word about the hollow base is probably in order at this point. 36 caliber percussion revolvers, like the 51 Navy and .36 caliber Remington Navy revolvers have a barrel bore of .375 inches. The modern .38 Special revolver has a barrel diameter of .357 inches. Makers of conversion kits for these revolvers use either the .38 special or .38 Long Colt cartridges for their conversions, because that is the nearest readily available casing.
It is recommended that hollow base bullets be used in these conversions to make up for the differences in the bore diameters. The pressure of the exploding gasses behind the bullet should force the hollow base bullet to expand out into the rifling lands. This provides a more accurate bullet fit without having to obtain heeled bullets of the correct diameter for the percussion barrel.
The Kirst cylinder for the 51 Navy is properly sized for the .38 Long Colt ammunition to prevent the gun from being able to load and fire a .38 special bullet with factory specifications. The reason is not related to the strength of the cylinder, but to the ability of the 51 Navy revolver frame from enduring that kind of punishment. It would take very few factory loads to completely destroy a 51 Navy frame.
Kirst has designed their cylinders to also allow the .38 special brass to fit, but .38 special cases must have an overall length of less than about 1.45 inches as measured using my two Kirst cylinders. That is about .10 inch shorter than the factory specification. Factory bullets will stick out the end of the cylinder and bind on the barrel to prevent shooting the gun.
The main difference between the .38 Special cartridge and the modern .38 :Long Colt is that the Colt cartridge is about an eighth of an inch shorter. We were not able to obtain any .38 Long Colt casings for our tests, so we simply used .38 Special casings and seated the bullets a little deeper than normal. We found this to be a satisfactory for our testing and may switch to the .38 Long Colt casings when they arrive.
We started by loading several sets of .38 Special cases with varying amounts of Hodgdon TiteGroup powder. We started with a 1.8 grain load and increased the load to 2.4 grains. We saw some surprising results from changes in the powder loads. For some reason, our group dropped nearly 5.5 inches with two grains of TiteGroup relative to the other groups.
We also tested American Pioneer Powder and Hodgdon 777 powder. We seated the bullets a little deeper into the cases to eliminate air spaces. These loads would be better when used in the shorter .38 Long Colt cases.
Please keep in mind that all tests were conducted using a single hand hold at fifteen yards on a breezy day. The relatively large group size is likely caused by my own testing limits and would probably have been much smaller had the gun been in a mechanical rest.
Our objective was to find a gentle load that would not stress the frame of the gun. We experienced no problems with primers backing out with any of these tests.
We have settled on a 1.8 grain load of TiteGroup for our 51 Navy revolvers for shooting smokeless powders. If we chose to shoot in a Blackpowder category, we will probably select 0.7 cc of American Pioneer Powder or 0.5 cc of Hodgdon 777.
The .45 Long Colt
We set out to establish some good loads for shooting cowboy action through our .45 Long Colt revolvers, including the conversion in this month's issue. Our objective was to find a load that can be handled comfortably with low recoil and minimal wear on the guns. We put a lot of lead downrange and heavy loads put a lot of stress on the guns.
We only tested smokeless loads using Hodgdon TiteGroup powder. We had the following results with out tests using a 4 3/4 inch barrel on a Uberti Regulator revolver. All loads were tested using a 160 grain round nose flat point bullet cast with a Lee mould. All bullets were lubed with Lee Liquid Alox and sized to .452 inches.
We will be adopting a 3.7 grain load for shooting in competition, because it shot well, had low recoil, and showed less unburned powder. The 4.0 grain load might be better for Duelist or Gunfighter categories where a little muzzle flip is desired for easier cocking. We did use a fairly tight crimp using the Lee Factory Crimp die.
One problem we experienced during out tests is that the Lee Auto Disk powder measure seemed to be unreliable at these low-level loads. We changed over to the Lee Perfect Powder Measure and had no further problems.
Note: All loads listed in this article are to offer starting points for loads we found work well for us in our guns. We recommend that only experienced loaders use custom loads and that you understand the characteristics of your gunpowder before deviating from factory specifications.