We would strongly encourage you to do away with the reload with retention, poor tactical technique.
The tactical reload technique describe is effective. Two main points to remember. First and most important, a lull in the fight exists that permits you the opportunity to perform the tac-reload, other wise shoot to slide lock and perform a speed reload. Second, storing your partially spent magazine in a pocket works great, but bear in mind you most likely train tac-reloads from your spare magazine carrier. So, if you go to slide lock, perform another tac-reload or heavens forbid a Type III malfunction you may find yourself in a more desperate situation when you can not locate your spare magazine.
In addition to performing the tac-reload, reindex the magazine and tactily feel for a live round. If there is one there stow the magazine back in your magazine carrier, if it is empty, ditch it or stow it in a pocket. This addition to the technique is to incorporate because there is a lull in firefight, so take the extra second or two to confirm what you got.
Now, if you carry a double magazine carrier it is not a major issue, but I carry a combination carrier with one spare magazine and light. If this is applicable to you then consider this as another option.
Later,
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Director of Training
The HALO Group