i've read a lot of negative things about the lead sled IF you use too much weight. the gun will not be allowed to move backwards during recoil, placing much more stress on the stock than should be. may not be an issue with the 7RM, as its recoil isnt' that fierce, just something to be aware of. plus, you're not taking one into the field, so practicing from one is pretty useless after you get your scope adjusted.
you can try the grind to fit limbsaver pad and have someone put it on for you, that will definately fit your rifle, though it may cost you a little more. i put a limbsaver on my old 06 and love the thing, but for my 7RM i just left the stock remmy rubber pad on it, seems to do fine. kick will also depend a lot on how you handle the gun, and how the stock fits and transfers stress to your body. thats why different brand rifles of similar weight sometimes kick very differently.
i have also read a lot of reports of the limbsavers melting in the safe/cabinet. they think it has something to do with cleaning solvents. i have not had this problem, and supposedly the new limbsavers have fixed the problem.
i am not exactly sure how the stock is set up on the 710, or how high your scope mount is. on my model 700, the cheek piece is too low for my comfort, so i added a cheek pad and it helped not only to raise my line of sight up with the scope, but also added some comfort as my cheek wasn't against the stock during recoil. i got one like this...
http://www.copsplus.com/prodnum3531.php
i know thats a lot more info than a recoil pad, but for limbsavers your only option might be the grind to fit model. you could also check for decelerator and see if they make one for the 710. call jc's gun and tackle in huntsville and see what they can do. they have a gunsmith that works there, fitting a pad to your gun shouldn't be a problem. you can also get some snap caps and practice your trigger squeeze in the house.
where is the hunt? my pops and i are heading to south dakota the last week in august for an archery antelope hunt.