I wouldn't worry about what the "factory" says end shake should be, I'd worry about what YOUR gun says it should be.
I know, at first that doesn't make since, but it does.
There are two things we need to worry about when it comes to what we call end shake. End shake is basically how much the cylinder slides back and forth when the cylinder is closed.
It can mean, that when the cylinder is slid to the rear, you have too much gap between the cylinder and the forcing cone (rear of the barrel). This allows too much gas to escape out the side instead of pushing the bullet out the barrel which means you'll loose a bit of velocity.
Then we have the possible problem of too much gap when the cylinder is allowed move too far toward the barrel. These could mean the firing pin cant reach the primer, or not hitting the primer hard enough to get it to go off.
To me, this is much more critical then excessive cylinder gap. A round not going off is much more critical then a bit of gas escaping.
If you loose velocity do to excessive cylinder gap, you can load a bit hotter or find a hotter round to make up for that velocity loss.
If the firing pin doesn't get the primer to go off firing the gun, it could be life threatening.
Even if the cylinder is slid back, the energy used by the hammer may be used to push the cylinder forward instead of setting off the primer.
Factory can give you a certain number but that number wont take into consideration of the wear of the revolver. Only you (or your gunsmith) can tell whats needed for your gun.
Brownell, Midway, and other gunsmith suppliers sell shims to fix either problem. They come in sets of shims about .002 thick. Depending on your problem, you need the shims that go on the yoke, forcing the cylinder to stay at the rear of the gun. When you add these ships or bushings (what ever you want to call them) you want to check to make sure to don't put too many in. Load the cylinder with EMPTY cases to make sure your cylinder rotates freely.
Same with cylinder gap, be careful not to add too many shims where there is drag between the cylinder and forcing cone. You want to check this with a dirty, warm gun. You fix the gap with a clean cool gun, it may work, but then will jam up when the gun gets dirty and expands do to heat with extensive shooting.
Hopefully, If I didn't answer your question, I at least didn't confuse you too much.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071