The Mr. Bulletfeeder dropper is gravity powered. When the case retracts, the inner dropper tube retracts with it, and the steel balls in the die move into place and close under the next bullet, ensuring only one bullet is released.
That is how it is designed to function, and how it does normally function – provided the dropper is free and clear and able to drop quickly, as designed, with the retracting case.
However, in some cases, the feeding tube spring adds side tension onto the dropper head (an issue more common on those machines where the toolhead moves up and down), or the dropper body may make contact with a close by die, creating friction that does not allow the dropper to move smoothly and quickly enough. Resulting in an occasional 2nd bullet falling out the dropper onto the shell plate.
The Mr.BF Dropper-Tensioning Spring Assembly is now available to resolve this problem for those experiencing it. This solution includes two carefully selected tension springs and two printed parts designed to fit onto your Dropper. The lower nut can be adjusted higher or lower on the die section to control how much extra downward force you are adding. It is recommended to add as little as possible additional tension, as too much force will increase wear by the case mouth on the dropper funnel below.
The upper collar assembles around the brass weight section, and rests atop the set screw, which you may need to back out a little to allow the support required. Multiple positioning tabs allow you to find the right angle for positioning the springs, without interfering with nearby dies or powder dropper.
The lower collar screws onto your die section, above the lock nut, and allows you to adjust its height to control the added downward force.
The double spring system creates a balanced and symmetrical downward force, that allows for smooth function of the die. The extra downward pressure will ensure that the dropper follows the extracting case, overcoming any friction and preventing those occasional annoying extra bullets from falling.