also the length of pull from the pistol grip to the trigger is longer on the 77/77k models than on the 97's, the 97's have a shorter length to the trigger and it to me feels a whole lot better and more comfortable and easier to shoot than my 77k!
these gun's are heavy so keep this in mind but IMO the 97's have a better feel and balance over the 77's, I'm 5'11'' and 175lbs with average size hands and arm length and the 97 fits me like a glove!