Here is a photo that shows how the Savage CV pilot circuit works - is has an "idle fuel mixture screw" and when you move the screw your are adjusting the amount of fuel that flows at idle. The air enters at the arrow marked (1), there is an air correction jet in the chamber under the slide diaphragm. This chamber gets filtered air from the oval hole at the top of the inlet to the carb. After the air goes through the jet it flows down a passage to an area just above the pilot jet, and the fuel coming up through the pilot jet combines in this passage with the air, and the air begins to atomize the fuel - the air/fuel mix then goes up to a passage that has holes into the inlet side of the throttle butterfly shown in the area of arrow (2). One or more of these holes goes directly into the inlet and supplies some of the fuel/air mix to the engine - the rest of it goes through the idle fuel mixture screw and it provides additional fuel/air and the amount is controlled by the setting of the screw. You will notice that the pilot jet is screwed into a threaded hole and it seats against the carb body at the top - there are no fuel or air passages on the side of the pilot jet....so no additional fuel and no air can enter the sides of the pilot jet.
The VM carb has an "air mixture screw" and you are adjusting the amount of air that mixes with the fuel coming though the pilot jet. The filters air enters at arrow (1), and some of the air flows to the holes in the needle jet to mix with the fuel coming from the man jet, the other path for air goes downward in the photograph to a passage that goes to the idle air screw shown by arrow (2). Fuel flows up through the pilot jet from the float bowl, and it mixes with air that is coming through the bleed holes in the side of the pilot jet. When you make and adjustment of the air screw you are controlling how much air can mix with the fuel - when you turn the screw in less air flows and the mixture becomes richer as the vacuum pulls more fuel and less air. You can see that the threaded hole for the pilot jet has an air passage around the sides of the pilot jet and the holes pass this air into the jet....fine tuning can be done by using jets with different size bleed holes or more or less bleed holes.
The stock Savage CV carb come with a pilot jet without any bleed holes - as there is no reason to have holes since no fuel or air can enter through these holes. You can use pilot jets with bleed holes in the Savage CV carb and it will operate the same is it would without them - as the holes can' t do anything. On the VM carb you have to use a pilot jet with bleed holes so the idle circuit can get air - you can change the size and number of holes to fine tune the operation of the pilot circuit.