Here’s a close-up look at the lock from an 1833-dated Model 1816 flintlock in .69 caliber.
These were the last flintlocks produced for the Federal government before the transition to the percussion ignition system, which was simpler, faster to use, and much more reliable.
Model 1816 flintlock in .69 caliber 
Model 1816 flintlock in .69 caliber 
Model 1816 flintlock in .69 caliber
