The pre-64 (M70's manufactured before 1964) was a controled round feed bolt action. Meaning that as the bolt was pushed forward it connected with a round in the magaine and began pushing the round foreward. As the round left the magazine the rim of the cartridge slid under the full length claw extractor thus prohibiting the round from accidentally falling out of the gun during the excitement of a hunt. The drawback to this design is that a round can not be put into the chamber by itself and then the bolt closed behind it. The round must be fed from the magazine so thet the rim will slide under the extractor because there is no povot point for the extractor to move around the rim of the case and engage the case.

There is also no ejection plunger to pusg against the head of the case making the case sit "crooked" in the chamber. Many people prefer this aspect of the design because it allows the case to sit flat against the bolt fase and therefore straight in the chamber and should lead to better accuracy because the bullet is starting out straight in the chamber.

The chamber also has a coned breech instead of the more common flat breech or recessed breech. In other words if you were to remove the barrel and stand it up on its muzzle the breech would look like a cone. This was to aid in smoother and more reliable feeding and provided a stronger design.


The easiest way to tell if you have a pre 64 is if there is a long claw extractor along the side of the bolt and if the recoil lugs have an angle in the front side of them. If these are not present then yours is post 64.

Winchester has since gone bock to usieing the pre 64 design on many of their M70's. They call it the classic. They also hace a controled round push feed that incorperates design elements from both of the controled round and push feed designs which IMO is superior to either of the other two designs.