i recently bought my first Smith & Wesson M&P 9mm..i love it so far....but i have a little quesion on 9mm ammo....does it vary in length...the one on the left is federal champion and the right is Remington...why is the federal almost 1/8 longer..is it normal...seeing the shell casing is the same size..both are 115 grain
Not unusual at all. Each manufacturer determines what their ammo's over all length will be. It will usually vary manufacturer to manufacturer, even though bullet weight is the same. Same thing happens whether it's ball or hollow point ammo. You can't see it, but they also use different powder, different powder charges, different primers, different bullet jacket thickness, hardness,etc, even though the cataloged bullet weights and velocities are the same...
with most modern guns (in my experience) it won't make a difference, but in older guns it sure can. I had a Walther P-38 that wouldn't feel Remington 9mm on a bet but it ate WWB all day long (or maybe it was the other way around). One of them was about 1/16" shorter than the other one and would just nosedive in the mag instead of feeding.
Note that another reason a cartridge could be shorter is because of bullet set-back and this can be dangerous. If the bullet gets pushed back into the case due to repeated unloading and loading (like with a CCW gun or duty gun that is unloaded every night) the pressure may increase when fired. Make sure you rotate the top round in the mag and if you see set-back when several rounds are placed side by side on a table (especially if all ammo is the same brand), then don't shoot that round.
9mm lenght
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