Well I have semi-auto pistols in .22LR, .32ACP & 9mm Makarov by Ruger, Colt, Walther & East German in the case of the Makarov, forget the exact maker. Not a single one of these has any grooves in the chambers or anything else special about them. They will all function reliably even with a dry chamber. I think those grooved chambers were for some special experimental uses which never really took hold.
""IF"" the bolt did not move prior to the bullets exit, it would not move at all. It is true it will have only moved a very short distance prior to the exit, but that movement is sufficient to impart the necessary inertia/momentum to the bolt to continue its rearward travel. When the projectile exits the muzzle the gas rushes out dropping the pressure instantly, if that bolt had not already received its rearward impulse it certainly would not receive it then.
