Not a week goes by that some one doesn't come to me at a match or call the shop and ask questions about reloading. Why do they ask me! I would guess it's because I have several years as a commercial ammunition loader working with several different loading machines.

    Most of the questions are about loading data. But then there are also the question regarding loading machines. The problem that I hear the most often from those who have just started reloading their own on progressive press is about their powder charge not dropping the same charge consistently round to round. The problem is usually traced to the use of an adjustable charge bar. 

    Understanding how it work and how to properly adjust it, almost always clear up their problems. The adjustable charge bar is a very handy item to have on a loading press. It allows you to choose the charge you want to drop for any given powder and any given round. Adjusting it properly is key to getting the correct powder drop over and over.

Figure 1 is a basic adjustable charge bar. 
1. Black is the bar body.
2. Blue is the adjustable block that changes the size of the opening the volume of powder flows in to be dropped.
3. Green is the adjusting screw that moves the block in and out making the amount of powder more or less.
4. Yellow is the adjusting screw retainer.

The two red circles show the areas that usually cause the problems with inconsistent powder drops.

Figure 2 shows the adjusting screw moving the adjustable block so that more powder will be dropped. Notice the retainer is not tight against the charge bar block. The screw head is.

Figure 3 shows a close up of the adjustable block and screw threads. Notice that screw threads are tight against one side of the adjustable block pulling it so that more powder will be dropped. This occurs when adjusting from one amount of powder to a larger amount of powder.

    If this method of adjusting the charge bar is used then when the loading machine is used the slack on the adjusting screw and the thread lash in the block will be remove as the charge bar is moved back and forth. The amount of powder will increase until the slack and thread lash is gone.

Figure 4 shows the adjusting screw moving the adjustable block so that less powder will be dropped. Notice the retainer is tight against the charge bar block. The screw head is not.

Figure 5 shows a close-up of the adjustable block and screw threads. Notice that screw threads are tight against one side of the adjustable block pushing it so that less powder will be dropped. This occurs when adjusting from one amount of powder to a lesser amount of powder

    If this method of adjusting the charge bar is used then when the loading machine is used the adjusting screw and the thread lash in the block will remain in the same position as the charge bar is moved back and forth. The amount of powder will be consistent from drop to drop.

    The problems of having inconsistent powder drops can usually be traced to the adjsutable charge bar. So if you want to drop 4.5 grains of your powder, start at something around  5.5 grains. Make your adjustments slowly and sneak up on the load you want weighing several drops at each adjustment before adjusting again.