There is differences... http://www.devcon.com/UserFiles/File/DevPermCAT_Edition9_LR.pdf I did a lot of research on bedding compound before I bedded my rifle. I ended up going with the 10110 steel putty. It was locally available and a lot of people have used it in bedding jobs. It came out great.
Exactly........you can do a great bedding job with any of them. ...regardless of how many KPSI's their claimed compressive strength is...get whichever is available and bed with it.....you will never notice the KPSI's