Patent No. 30,990. The patent actually covered two improvements, both of which were already being used in production and the patent were probably an after thought just to be sure modifcations made to the gun could not be copied by others. The two improvements were (1) to the barrel locking latch, and (2) a ramp, or raised portion of the recoil shield was located directly behind the cartridge when it was in firing position in the cylinder. This allowed the cylinder to freely keep rotating after cartridges were fired, as the rim of these cartridges often bulged out after firing and sometimes interfered with the cylinder's rotation. A copy of the patent can be obtained from the US Patent office. Ed.
