Based on the serial number and cavalry markings, I can provide some historical details on your 1865 Spencer carbine:  _{^{geometry dash}}
- The serial number of 3894 falls squarely into Spencer production in 1865, the final year of the Civil War. Approximately 13,000 carbines were made that year.
- The "Co K 9 CAV" stamping indicates this carbine was issued to Company K of the 9th Regiment California Volunteer Cavalry.
- The 9th CAV served in the Arizona and New Mexico territories late in the war patrolling for Confederate sympathizers and outlaws.
- So your Spencer likely saw action on frontier cavalry missions under Lieutenant Colonel William McCleave and Major Emil Fritz.
- The "Stabler cut-off" is a unique modification specific to the 9th CAV's Spencer carbines only, ordered by Colonel McCleave. It disabled the hand-cocking lever for safer handling by cavalry troopers.

With all due respect, a correction about the Stabler cutoff: There was no "hand-cocking lever". The idea of the Stabler cutoff was to prevent the action from opening far enough to feed a round from the magazine, so the arm could be used as a single-loader, supposedly to conserve ammo, until rapid fire was necessary. As on all Spencers, the hammer had to be manually cocked after the round was chambered.  In fact, the safe procedure for firing a Spencer is to half-cock the hammer, work the lever to chamber a round from the magazine (or after single-loading a round), pull the hammer to full cock and fire. But, in a firefight situation, the hammer could be full-cocked before working the lever, and the trigger squeezed to fire. The reason for half or full-cocking the hammer, is to prevent slam-firing, as the rimfire fireing pin is longer than the breechblock. With the centerfire conversion, I set the firing pin up so it was an inertia pin, like a M1911A1. Just have to be careful not to shorten the pin too much!
BTW, the 9th Cav and the 10th were the Buffalo Soldiers!

I intend to. I recently picked up a Winchester 1880 loading tool for the caliber.

  Well Now 

I are in complete agreement with DaveT and CraigC, your hugely ahead to Try before you Fly.  Our individual idea(s) of perfection may well leave you stone cold.

A BIG THANK YOU to the Deacon as well.  His reference provides a ready source of ammunition loaded with different weight/power bullets you can try without braking the bank.  And you get a swell cartridge bag to boot.

Thanks, Johnny.

Slim

Hello everyone. I just purchased an 1865 Spencer Carbine from an estate that has been hidden for many years. This is a neat little carbine with serial number 3894. It has a Stabler device and is stamped on the right side of the receiver Co K 9 CAV!! Can anyone help with this serial number or any other info on the gun. Thanks in advance.

Based on the serial number and cavalry markings, I can provide some historical details on your 1865 Spencer carbine:  _{^{geometry dash}}
- The serial number of 3894 falls squarely into Spencer production in 1865, the final year of the Civil War. Approximately 13,000 carbines were made that year.
- The "Co K 9 CAV" stamping indicates this carbine was issued to Company K of the 9th Regiment California Volunteer Cavalry.
- The 9th CAV served in the Arizona and New Mexico territories late in the war patrolling for Confederate sympathizers and outlaws.
- So your Spencer likely saw action on frontier cavalry missions under Lieutenant Colonel William McCleave and Major Emil Fritz.
- The "Stabler cut-off" is a unique modification specific to the 9th CAV's Spencer carbines only, ordered by Colonel McCleave. It disabled the hand-cocking lever for safer handling by cavalry troopers.