I like to carry my spare magazine on the waistline in order to facilitate the fastest, and most fumble-proof, reload possible. The problem is, I find this difficult to pull off. I used to wear the magazine at my off-hand appendix position. First, I always found it uncomfortable. Second, I moved to keeping my knife there, as I think the knife is more practical in that position. So, I now pocket carry my spare magazine.
There is no getting around it, reloading from the pocket is much slower than from off the waist. I can actually do a reload, from concealment off my hip, in under 2 seconds. From the pocket, it takes me 3.5 to four seconds. So, I won’t lie, there is a significant difference. However, I am willing to make this compromise.
Obviously, reloads in civilian defensive shootings are statistically infinitesimal. I think the ability to quickly access a blade to make space against a contact-distance threat outweighs the ability to do a fast reload as a civilian. This being the case, I relegate the reload to the pocket, as I have a hard time concealing a spare mag on my off-side hip.
One thing I have found to be absolutely necessary for pocket carry is a dedicated mag holder so that the mag stays properly oriented in the pocket. There are some products that will actually keep the magazine clipped to the pocket. I don’t like the clipping options, but I keep the magazine in a soft magazine pouch made by Sticky Holsters and it works good. The magazine does not flop around and it is always oriented in the right direction.
While not ideal, I think pocket carry for the spare magazine is acceptable for the civilian self-defender and is certainly better than carrying no spare magazine. Should you find yourself in the unlikely, yet dire, circumstance of needed extra ammunition it is good to have it, even if it is a slower reload compared to a spare mag carried on the waist.