[QUOTE=Guilherme;5694928]
This is a half truth.
In discussing standards you also have to remember that you’re looking at several centuries of military equine use. In each era there were both similarities and differences from other eras.
The modern (post 1900) U.S. Army planned to retire (declare surplus and sell at auction) Cavalry horses at the age of 16. This was the peacetime standard. They were replaced with remounts that were 4-5 years old. Any regimental commander who had a “wastage” that did not meet this standard would be questioned about his procedures and practices.
I don’t know what the practices were in the Artillery or in the British services.
In wartime the horse was, in fact, expendable. You didn’t do such a thing lightly (nor did you do it with tanks, aircraft, ships, or troopers). Any trooper who failed to properly care for his mount could find himself, suddenly, in the Infantry (afoot, in hostile territory, and without most of his gear). But losses were going to be part of process and they had to be expected and planned for. This was not evidence of callousness or cruelty, only recognition that Gen. Sherman was right when he said, “War is Hell.”*
The weight bearing standard, however, is the question. I’m still trying to find the “root” of the 20% Rule and I’m striking out so far. I did locate a gent who has a copy of the U.S. manuals from 1922 which allegedly cite the 20% rule. He’s checking on it for me (but is also in the Texas State Guard on the Border and is a bit busy right now). So I’ll be patient. 
The reason for the higher British number is that the British tack was significantly heavier than American tack of the day. The 1917 Cavalry Journal article that published the British load put the tack weight at 43 lbs. The U.S. load was closer to 30 lbs. I think some of the British equipment was also heavier and they carried a few more things.
I guess we’re still at the stage where the fat lady hasn’t sung yet (pun intended). :lol:
G.
*The actual Sherman quote (from his 1879 speech to the graduates at West Point is “I’ve been where you are now and I know just how you feel. It’s entirely natural that there should beat in the breast of every one of you a hope and desire that some day you can use the skill you have acquired here. Suppress it! You don’t know the horrible aspects of war. I’ve been through two wars and I know. I’ve seen cities and homes in ashes. I’ve seen thousands of men lying on the ground, their dead faces looking up at the skies. I tell you, war is Hell!”[/QUOTE]
I think rather than a half truth, I did not fully explain so here it is for those who look at such things. It is not adequate to compare warhorses and the policies which were made for the sake of efficiency and the hope of winning a war, which of course is hell (you think we might want to stop a few ourselves), with pleasure riding for peaceable purposes. Their guidelines were at the outer edge of pushing the envelope for the sake of meeting the hoped for end of the war. I would say that cavalry guidelines for weight bearing for the purpose to which we use the horse is not useful.
In other words ratio of weight of rider to horse is a fallacious construct. As some have said, many factors play into that equation, fitness of both horse and rider have a much more important role to play than a weight ratio. After all, in war, many were expected to die. I do not think much was taken into account as far as humane policies of practice for either the horse or the human. I am certainly not denigrating the great Generals Grant, Sheridan or Sherman, but they were fighting a killing war as Sherman expressed it in the quote you found (thank you for that).
Just by the by, the surest footed horse I ever rode on a downhill gallop was also the smallest, she just happened to be a Morgan.;).
