cannelure

It has the cannelure which is located at the rear, on the portion of bullets of this type.

That is the groove around the base of the bullet, also known as the cannelure?

There is a cannelure, that would be the position at which the projectile is crimped and held in the cartridge case.

Cannelure, kan′e-lūr, n. a groove or a fluting: a groove round the cylindrical part of a bullet.

The lubricant can then be poured around them until it rises high enough to fill the top cannelure.