Several weeks ago, a friend gave me a box of new, factory American Eagle (Federal) .357 mag 158 grain jacketed soft points. Lot #2946508508. He had bought these at Walmart about 2 months ago for a revolver he since sold.
Went to the range this morning, and loaded six in my S&W 4 inch 586-no dash, a proven gun with thousands of rounds thru it. Fired one round D/A, when the gun jammed (cylinder refused to rotate)
I could feel it binding, and thought that maybe the primer of the fired round had flowed. When I opened the gun, that was not the case. It appeared an unfired round was rubbing against the recoil shield / breach face.
I isolated that round, and compared it to the other four unfired rounds. The bullet seating depth was identical, but it appeared, visually, that the rim was a little thicker then the others.
I made sure the chambers, breach face, and under the star were clean, then loaded the rest of the ammo six at a time, checking for function by cocking the hammer, and letting it down without firing. I found 3 additional rounds that dragged badly, retarding cylinder rotation. Upon inspection, all had visibly thicker rims than the remaining, functioning rounds. Primers appeared properly seated by look and feel.
I fired the rest of the good ammo, then tossed the bad rounds. With hind sight, I wish I had saved them, and ran a micrometer on them when I got home.
I have ran a lot of ammo thru revolvers over the years, but this is the first time I have ever seen new factory ammo with overly thick rims.
If there is a point to this drawn out story, I guess it is that you should ALWAYS dry run and test for function any ammo you intend to carry for self defense thru the intended gun before you bet your life on it. Weird stuff sometimes happens.....
Larry