I am pretty sure I would know, what I fired, blank or live round.
Interestingly, I heard the same story of one blank round in a firing squad, in the times when there was capital penalty in former Yugoslavia, as well.
Like some customary procedures on two different continents?
I went to search on internet, and it seams wikipedia agrees with me.
en.wikipedia.org
In practice however, firing a live round produces significant recoil, while firing a blank does not.[6] This is especially significant with bolt-action rifles. As a result, it is not realistic to assume that, after the fact, trained soldiers will be unaware of which they shot. This is reflected in first-hand reports such as Pte. W. A. Quinton’s, who served in the British Army during the First World War and served on a firing squad in October 1915. Per his account, he and 11 colleagues were relieved of any live ammunition and their own rifles, then issued replacement firearms for the task at hand. After a short speech by an officer, the squad fired a volley at the condemned man. Quinton stated that "I had the satisfaction of knowing that as soon as I fired, the absence of any recoil [indicated] that I had merely fired a blank cartridge".
In more recent times, such as the 2010 execution of Ronnie Lee Gardner in Utah, US, one rifleman may be given a "dummy" cartridge containing a wax bullet, which provides a more realistic recoil.[7]
Moreover, recently a friend of my died. I attended the funeral
He was entitled for a military funeral, with military honors.
Soldiers were firing modern full-auto rifles, in the air.
Blank rounds, of course.
After each shot, they had to cycle the bolt manually. Semi automatic function with blank round did not function.
In old times when army was issued ak47 type rifle or SKS, for training each rifle was issued with a device to increase recoil (i am not sure what is English term for this), so during maneuvers or tactical training with blank rounds automatic fire arm could function in auto mode.
Below is photo from internet for such device on SKS rifle, for example. Putting that on a rifle, or not putting it with blank round on automatic rifle of single member of firing squad would be at least naïve, in my view.
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