It is important to bring a whole lotta magazines to class, because nobody wants to be That Guy. You know, That Guy? That Guy who only has two or three eight-round mags and is constantly holding the class up to thumb rounds into them from his pockets between evolutions? Don't be That Guy.
I grabbed my eight best spares and tossed them in the range bag the morning of day one. I also threw my backup 1911 in the bag.
The gun on my hip was my Springfield Pro, which has a magwell. The magwell requires thicker bumper pads to firmly seat the mags. I have two Wilsons with low-profile pads on the bottom specifically for use with my Colt, which does not have the Smith & Alexander magwell.
Two of the magazines I picked up were those two magazines. Can you see where this is going?
Now I have six mags that work easily in the Springer and two that are delegated to my right hip pocket. Between strings, I'm thumbing rounds out of them to top off the mags in my left hand pockets. Luckily I stayed ahead of the pace and avoided That Guy-ness, but on day two, I was using the Colt, which can use all of the mags regardless of baseplate thickness.