I can't. I don't understand why everyone thinks the scar's recoil makes it terrible. If you ask me it's how recoil SHOULD be for at least most guns.. Everyone complains about no recoil SMG lasers because everyone uses one and they kill everything and then I go to try one out and I can't use one.
I have issues of a similar nature. I can use both, but never in the same grouping of time.
It's almost like I teach myself how to play with one and do great, then when I need to switch I play awful for a while until I get the hang of it. Once I switch back, same thing happens.
Although sometimes it just the gun. For example I am going for gold with the M27 which I think has almost no recoil. Once I prestige I picked up the MTAR for a while, a gun which again I think has no recoil, and I was doing awful with it.
I do agree that the SCAR has good recoil. Having all guns have little to no recoil is strange. I think that's where BF3 beats COD. The guns have a more realistic firing experience (at least for video games).