This installment of Tiger McKee’s Skill Set Classics goes back to March 22, 2012. Based on current events, it’s a good time to review.

Loading your AR mags may sound like a simple thing, but loading the correct number of rounds is very important. The total depends on a lot of factors, but the goal is to discover how many rounds you can load –and -- with the bolt closed, still easily seat and lock the magazine into the rifle.

During a recent class we were discussing this and Matt, one of our instructors, told us about a test he ran during agency qualifications. Shooters loaded their mags with thirty rounds and were told to lock them into the rifle, rating how easy or difficult it was to seat the mag, 1 being easy and 10 difficult. When seating the AR mag with the bolt closed the bolt carrier presses the top round down into the mag. If the top round can’t be pushed down the mag will not lock in. The fully loaded aluminum G.I. mags were rated an eleven.

They continued, removing one round for each test. At twenty-five rounds the mags were consistently easy to seat. When first learning to work the AR, I arrived at the same conclusion, and I must admit part of it was the fact I could load two- and one-half stripper clips and I was good to go. I didn’t have to count. (Remember, this is before the fancy loaders available today.)

There are a lot of different mags and components like followers and springs available today. The number of rounds a mag will hold and easily seat into your rifle will vary. Your job it to figure out what works for you and your equipment. “Easy to seat” is a subjective term. What works for me will be different from someone with stronger muscles or an injured shoulder or elbow.

We want as many rounds in the mags as possible. You never know how much you’ll have to shoot. At the same time those extra four or five rounds won’t do any good if the mag won’t seat in the rifle. Even if the bolt is locked to the rear -- say during an empty reload -- with a lot of rifles, the bolt won’t have enough power to strip off the top round from an overloaded mag. There’s too much spring pressure on that first round.

The same thing applies to some pistols, especially those with high-capacity double stack mags. Loading the mag completely full applies a lot of pressure to the spring and sometimes, even when the slide is cycled aggressively, it won’t chamber a round. I know several guys with high cap pistols who load with one or two rounds less than “full” because it guarantees proper functioning.

Having to take the time to smack the bottom of the mag to seat it may cost you an extra second or two on the range. In a fight, on the ground with your elbow trapped underneath your body the ability to smoothly index the mag, slip it in and easily lock it is victory.

— Tiger McKee