The same time spent mashing the forward assist is better spent running the charging handle. Eugene Stoner himself agreed.
Won't always give a useful result. If the carrier is hanging up/slowing down because something is wrong with the magazine, which can be a number of things, doesn't even have to be a misfeed (hell, the magazine can be fine and there could simply be dirt between the carrier and receiver wall), pulling the carrier back and letting the spring shove it again may just make the same thing happen again.
With the assist you can push the carrier past the point where it slows down and ensure that a round is chambered, it doesn't have to involve any kind of obstruction in the chamber, and it doesn't have to involve the magazine trying to feed the cartridge at a funny angle.
In a situation like Kyle's, where split seconds matter, I think that the assist was slightly faster, but more importantly much more definite, getting that single shot off was critical to making Gaige not pull the trigger, whatever else happens after that has to take second priority.
Could this have been avoided with a better quality rifle, a better quality magazine, and better quality ammunition? Probably, but fact is still that the assist helped in a situation which was less than ideal.
Additionally, various different people who shoot AR15s suppressed a lot tell me that since the gun gets dirtier faster, the forward assist gets a lot more useful.
I’ve had so many customers over the years use the forward assist to beat steel case ammo into the chamber that is misfeeding from questionable magazines.
That's one of those things about contexts, it's certainly a bad idea to tap the forward assist when a cartridge isn't feeding, just like it's not a useful approach to tap the slide on a pistol to try to make a misfeed feed. Magazines can also be damaged in the field, so what was once a good magazine may stop being one.
That said this is a subject I don’t really care much about. We sell uppers with and without forward assists. Buy whatever you want.
For sure, there's plenty of room in the world for both kinds of uppers, and I see the appeal in the slick-side rifles. I'm simply of the opinion that the forward assist
isn't useless, and that quite a lot of criticism against it isn't actually very poignant.