[TABLE="class: norm100 shot"]
[TR="class: bg"]
[TH].354-.360
[/TH]
[TH][/TH]
[TH].38 Smith & Wesson
[/TH]
[TH][/TH]
[/TR]
[TR="class: mushroom"]
[TH].355[/TH]
[TH][/TH]
[TH].380 Auto
[/TH]
[/TR]
[TR="class: bg"]
[TH].355[/TH]
[TH][/TH]
[TH].38 Super Auto[/TH]
[TH][/TH]
[TH][/TH]
[/TR]
[TR="class: mushroom"]
[TH].355 - .356
[/TH]
[TH][/TH]
[TH] 9 mm Luger
[/TH]
[/TR]
[/TABLE]
The bullet diameter is on the left, and the caliber it relates to is on the right. Odds are that it is a revolver bullet, because the semi auto rounds are generally jacketed so they will feed out of the magazine without the soft lead bullet catching and jamming the gun. My guess would be a .38 revolver, of most any brand, Smith and Wesson and Colt being the two biggies, but there were many others. Those type of bullets are being manufactured today, although aren't as common as they used to be.