- The conversion consists of an open-ended rotating cylinder and a fixed breech-block with a gate that pivots open for loading/unloading the cartridges.
Just to help clarify the calibre issue with these Conversions Wikipedia lists these thus:
Colt 1851 Navy Revolver .. Cartridge: .38 Rimfire / .38 Centrefire (conversions) Calibre .36
- So that's clear eh.
How it is? - is that the .36 Calibre Navy used 80 grain lead balls that measured .375" - .380" diameter which had to 'obturate' (squeeze-down) into the .375" bore and rifling.
Colt London Navy Conversion (.38 really .36?)(Or .36 really .38)
with my Ruger Old Army .44"(really a .45")
You surely DO learn something new every day - when looking for history on this conversion I read that the very first Navy model Thuer conversions used a tapered cartridge to insert into the chambers from the front - thereby avoiding the Rollin White patent for open ended cylinders:
Thuer Tapered Brass Cartridges.
Only approx. 1,000/1,500 guns converted this way.
- Then it seems that in 1871 a Colt employee Charles Richards was awarded a patent for his cartridge conversion and that was further improved the following year 1872 by another Colt worker William Mason - so these later Navy Cartridge-Conversions should be properly known as an '1851 Richards-Mason Navy' .
These conversions were very popular as they were cheap and the guns were worked hard by the cowboys of the day - being used to hammer staples into posts to fix barbed-wire fences etc.
- It seems that you can either use .38 Special cartridges (pills measure .357" diameter) loaded with soft lead hollow base bullets to bump-up to bore size - or you can use .38 Long Colt cases with a correctly sized stepped heal bullet.
Life gets complicated eh..