To my knowledge, the tradition of tapping the magazine to ensure all the rounds are towards the back end of the magazine comes from the military. That’s where I first learned it. Drill instructors and senior NCOs told us to tap our mags to make sure the 5.56mm NATO rounds were flush with the backside of the 30 round magazines. They often demonstrated by hitting the backside of the mags on our Kevlar helmets.
Maybe there was an issue with this in the past, but I don’t see how. Using USGI magazines, I have never had a feeding issue stemming from not having rounds flush with the back of the mag. Of course, when I load my mags, I make sure the primers are against the back of the mag to begin with, but even if the rounds are forward just a bit, it won’t cause a problem.
Sure, it’s possible the tip of the round could catch on the front of the mag, but it’s not likely. If there’s a constant catching and failing to feed due to the magazine, throw the mag away.
Using blank rounds could be slightly different since blank 5.56 ammo can creep forward a little more because they’re shorter than live rounds, but again, I’ve never seen an issue. Even then, if the rounds (blank or otherwise) shift towards the loading end, so what? It shouldn’t affect the operation of a quality M16/M4 or AR family firearm. I’ve seen other malfunctions, but never one because the rounds weren’t touching the backside of the mag.
Now, if you drop a mag and the stack of rounds are knocked out of alignment, you may think that tapping the back of the mag will help put them back in order—and it might! If you’re in a warzone and you have the time, tapping the mag a couple of times to realign the rounds may be a worthwhile exercise. I’d do it. But when you’re on the range, just shoot the gun. I really don’t think it matters.
Now, if you’re used to wearing a helmet when you shoot, like those in the military, what you really want to avoid is getting in the habit of hitting the mag on your Kevlar because some day when you’re wearing a patrol cap, you might accidentally smash the mag into the side of your head. Yeah, I’ve actually seen that happen more than once. Inevitably, hitting a 30 round mag against something, including your head, isn’t really worth it.
The views and opinions expressed in this post are those of the authors and do not necessarily reflect the position of Guns.com.
Safety warning: Jeffrey Denning is a long time professional in the art of self-defense and any training methods or information he describes in his articles are intended to be put into practice only by serious shooters with proper training. Please read, but do not attempt anything posted here without first seeking out proper training.