Here is a link to better pictures of the differences between an Accustock rifle and Non-Accustock.
At least with the old Accuwedge model. The only thing not allowing the barreld action to fit in the stock is the recoil lug as was described earlier.
Since they use the same action, it would only take me a few hours with a file to get the recoil lug on one of my centerfeed rifles to fit the accustock. Like I said if you have a little patience and take your time you could get it to fit easily enough. I think it would be safer to change the recoil lug shape than to open up the bedding block as you don't know how much aluminum is really in there. If it is a heavy recoiling rifle it might cause some problems it the recoil lug area is weak.