The horizontal carriage allowed us to fire immediately from the waist if we ran into an ambush and it also allowed fast entry into the prone.
Your videos are cool but very civilian: there's never any reason to fire full-auto from the offhand (standing) position in combat. Full auto is almost always fired from the prone, which is what you'd better be if the first rounds the enemy fired haven't already got you. I have no idea why our YouTube cowboys think that that is way we employed them - but of course, they would be difficult to control.
I was as a 21 year old Lance Corporal that had a relatively free hand in picking a weapon to keep me alive and I was very happy with my '14. It was accurate - I successfully engaged an enemy sniper at 600m - and it was controllable and exceptionally dependable in an environment that was always hot, wet, and filthy. I could reliably keep a 3-4 round burst with the size of a human body at 150m+. Don't need to ask me how I know that.
As I said earlier, when I was wounded in May '67, there was a fast grab for my M-14. It was the best weapon for many miles around.
re: “Your videos are cool but very civilian: there’s never any reason to fire full-auto from the offhand (standing) position in combat. Full auto is almost always fired from the prone, which is what you’d better be if the first rounds the enemy fired haven’t already got you. I have no idea why our YouTube cowboys think that that is way we employed them - but of course, they would be difficult to control.”
There are a number of reasons you see people shooting these while standing.
1. Many ranges prohibit prone firing these days; seated or standing are your only options. “Don’t have a choice if you want to fire it,” is a valid reason. :D
2. Standing/offhand auto fire is a doctrine used in some foreign militaries and at least after the M16 was adopted, our own with the 5.56. My friends just back from the Sandbox tell me that they did use their rifles in full auto from the shoulder more than a few times. They also reported that their full auto usage overall was limited. FYI, as of 2014, the Army has begun retiring all the burst fire M4s and M16s and has re-equipped with the full auto versions.
3. Our own military (and many others) considers whether or not a full auto rifle is controllable or not based on this type of firing - standing up, from the shoulder. This was how they decided the M-14 was not controllable in full auto - and by that standard, they are correct.
The FAL, to continue to use the example I’ve used on this thread, was also considered “wildly uncontrollable” on full auto at the time. There’s period video out there of people using the techniques of the time desperately trying to hang on to the thing in full auto either from the shoulder or from the hip, so you can see why and how they thought this. It was so bad that the British completely eliminated full auto fire from their versions of the FAL. The Germans and some others kept full auto but fitted integral bipods and instructed their troops to never use full auto except when prone with the bipod deployed. However, technique has changed considerably since then and as demonstrated above a modern shooter can reasonably easily control a FAL on full auto from the shoulder. The FAL’s weight, geometry and operating system are just fine for this use, as it turns out. Unfortunately, the M-14 in its original stock is not.