Front sight tools are nice, I never saw one in inventory or issue for my 22 years Reserves. The standard solution was for the Range Officer to supply a bag of finish nails for sight adjustment. Works just fine.
My last qualification in the MP's was at Camp Clark, MO, and when I slung up I was getting 3-4" shifts in impact, on a short range. Completely unacceptable, no way to zero - I finally remembered that military weapons are NOT free floated like an International .22, so I unslung and cradled the forearm in the crook of my arm. Expert, again.
I've since attempted to estimate how many foot pounds of force a tightly slung weapon endures. With the sling at arm numbing pressures, hand forced against the guard, and gas block pulled almost exactly in the opposite direction, it could be 25-40 pounds easily.
Try it yourself - with a hasty position against a door post or tree, pole, or the side of a fixed target stand, press the gas block against it while shooting and see just what you get. ALL military weapons with sling points on front sights. blocks, or bands will shift POI, the issue isn't that they are somehow faulty, it's using a sling in combat like a range shooter when said sling ISN'T part of the combat kit out. The Infantry School at Ft. Benning circa 1983 removed the sling as part of the basic configuration in the field. Reasons included making less noise, not having the weapon on your shoulder when it should be at the ready, not snagging every piece of brush or gear on you tangling and impeding a quick sight picture, etc. We also NEVER used the "carry handle," that was more than an instructor's tripwire for pushups, it was a point of professional pride. You can't shoot a M16 carrying it like luggage, one too many newsclips from Vietnam exposed that newb behavior.
Having also trained MP - sure, there's a place for sling use in street patrol or CQB. Completely different game, you detain and search individuals, it's a police environment, part of the Low Intensity Conflict scenario. It's not field combat where you are assured of being in the sight picture of someone else, and where you need to be completely uninmpeded in your response.
Like any other accessory, if something has an optimum situation for use, it also has an opposite worse case where it has no place at all. Unfortunately the shooting public follows fads and doesn't keep the big picture in mind. Case in point, for the first time in history, the F150 was sold with more 6 cylinder engines than V8's - and since most users are actually commuters, you have to ask why it took them so long to get it.
I'll sharpen the point, since you train like you fight - don't shoot with a sling, don't sling up when hunting, and don't spend money on them beyond getting some kind of strap to carry it out of the woods at the end of a long day hunting. I encourage all those who would use a sling to practice with it at the range, at home, and in the field. Find out for yourself what works for you, rather than simply accept the preferences of someone else insisting on their view of an appropriate tactical response.
Hook a sling one time on a doorknob, lamp, or piece of furniture exiting a bedroom to investigate that noise in the night, maybe it's not the appropriate choice. If you don't practice and train with it, you really don't know whether it works for you.
