Found bullet. What caliper?

[Hangtown]

Found this while prospecting a hole I found in the Bay Area near a Lil creek this morning. Thought I would ask for some help on this Lil guy. Posting from phone so let me know If pics don't make it on. Thanks in advanced

 

[capt-zero]

Need to get some measurements with a pair of calipers to be sure, but at a glance looks to be an old .44.

 

[TheCannonballGuy]

Your photos with a ruler show the measurement of the object's diameter is a tiny bit less than 1/4-inch, which would be a .22-caliber bullet.