Full Length Die Adjustments

Full Length Sizing Die Adjustment

When using our  full length sizing dies for rifle cartridges, the die should be turned in to touch the shell holder and then enough more that there is no daylight between the top of the shell holder and the bottom of the die during the sizing process.  This is the preferred method because the act of sizing sometimes results in flex that prevents the shell holder from touching the bottom of the die.

Lee dies are designed so that the shoulder of the case is not sized until the very top of the die has been reached.  This is done for two reasons; first, we don't want the die to overwork your brass and second and more importantly, we do not want to invite headspace problems.  Pushing the shoulder back too soon can create a situation that can eventually cause case separation and a dangerous situation.

If you note that your Lee Die don't appear to push the shoulder of your case back, ensure that you are adjusting the die so that there is no daylight between the top of the shell holder and the bottom of the die during the sizing process.  If you see daylight at the top of the stroke, readjust the die downward and repeat sizing until it disappears.  If your case is still difficult to chamber, you can send the die back to us with a sized case and we can modify the die to minimum SAAMI specifications.

Lee Precision, Inc.
4275 Highway U
Hartford, WI  53027


Carbide Sizing Die Adjustment

With the shell plate or shell holder at the top of the stroke, turn the die in until it touches the shell holder and set the lock ring. 


Collet Die Adjustment

If you are using the Collet die in an RCBS Rockchucker press, or a similar design that toggles over center at the top of the (ram) stroke, this applies far greater force than is necessary to resize just the neck of the case, and can damage the die or collapse the case.  To correct this situation, adjust the die two full turns into the press after the die contacts the shell holder with the ram at the top of its stroke, rather than one as in the instructions.  This will stop the press before it gets to the toggle over point.  With a press without having an over center feature, apply about 25 lbs. of pressure to the handle once it bottoms out to resize the case.  On most presses, this translates to over 600 lbs of pressure on the ram.

The collet might be stuck in the closed position from closing the die without a case inside. Remove the cap from the top of the Collet die and push the mandrel, collet sleeve and collet out through the top of the die. Open the collet back up with a tapered punch or Phillips screwdriver.

If this occurs with a full length sizing die, the decapper/expander is out of adjustment. The decapper/expander should be flush with the top of the decapper clamp. If it protrudes more than 1/4 inch, the die will be resizing the inside and outside diameter of the case neck at the same time, resulting in a collapsed case shoulder.


Powder Through Expanding Die Adjustment

The quickest and most accurate way to set this die is to put the shell holder or shell plate at the top of the stroke and turn the die in until the bottom of it touches the shell holder or shell plate.  At that point, back it out a half turn which should set the die to begin giving you the proper flare to the case mouth. 

It is important that when attaching a powder measure to the die, that it be tightened so that the expander plug cannot move up into the die defeating the purpose of setting it in this fashion.


Seating Die Adjustment

The trick is to set the bullet seating depth first, then the crimp.  With an empty, sized case in the shell holder, hold the ram at the top of its stroke.  Turn the bullet seating die body down over the case until you feel it come to a stop.  This will be when the case mouth contacts the crimp shoulder inside the die.  Mark this position by turning the lock ring down against the turret or press frame.  Now adjust your bullet seating depth.  Once you have the bullet seated to the desired depth, back the bullet seater adjuster out about 1 turn.  Now turn the bullet seating die body in to apply the desired crimp.  Once this is established, hold the ram at the top of its stroke and spin the bullet seater adjuster down until it stops. 

It is a good idea to carry this out with an empty case, so that after you have seated the bullet, you have a perfectly safe "dummy" cartridge (or gauge) to repetitively set seating depth and crimp on future occasions.

Once you have this "dummy" gauge, all you have to do is place it in the shell holder, raise the ram to the top of its stroke, turn the bullet seating body down until it stops, and then turn the bullet seating depth adjuster in until it stops.  Since the crimp and the seating depth were already set, the die will return to very close to the same settings.


Rifle Factory Crimp Die Adjustment

The amount of crimp applied will be consistent if your press has mechanical stops built into the lever linkage, and you lower the lever to the stop every time.  Start with the Factory Crimp die turned into the press until it stops against the shell holder with the ram raised all the way.  Lower the ram, and turn the die in one full turn.  Now try crimping a case, making sure that you raise the ram (lower the lever) all the way to the stop.  You will feel slight resistance at the top of the stroke, as the crimp collet is forced up into the die body. 

If the crimp is not firm enough, turn the die in another 1/4 turn and try again.  If you turn the die in to the point where the four slits in the collet are closed when the ram is raised all the way, you have reached the limit.


Handgun Carbide Factory Crimp Die Adjustment

With an empty case in the shell holder or shell plate, turn the die with it's finger adjustment all the way out into the press until the bottom of the die touches the shell holder or shell plate.  Turn the finger adjustment knob down until you feel it stop which means that the crimp sleeve has en gauged the top of the case.  Remove the case and turn the adjustment knob in an additional 1/2 turn which is adequate for most loading.  Turn the adjustment knob in or out to suit.


Dead Length Bullet Seating Die Adjustment

The idea behind the floating bullet seater plug or "dead length bullet seating" is as follows;  If you look inside the bullet seating die, you will see a restriction about 3/4 the way to the top of the die.  This restriction is only .001 larger than bullet diameter, and is positioned so that when the bullet starts to seat into the case, the bearing surface will be passing through this restriction. 

The bullet seater plug, being free to move axially, and due to the shape of the cavity will find the center of the nose, and a properly prepared case will find the center of the base of the bullet.  The die should be turned in to touch the shell holder and is designed to be adjusted that way to eliminate clearance in the press for a more uniform bullet seating depth.

Most case/bullet alignment is determined in the resizing die.  If the case neck is sized too small, the bullet will actually resize (open back up) the case neck when it is seated.  If the case neck is thinner or softer on one side (and they usually are) the bullet will push out more on that side.  Excessive crimp or an out of square case mouth can also cause bullet run out.

Universal Decapping die adjustment

The trick to adjusting the decapper is to just tighten the decapper clamp enough so that the decapper will push out 90% of the primers, but the very stubborn ones will cause the decapper to slide up through the clamp.  Start with the decapper clamp just tight enough to keep the decapper from falling out the bottom of the die.  Try to resize a case.  The decapper will probably slide up through the decapper clamp.  Tap the decapper back down flush with the top of the decapping clamp, tighten the clamp another 1/8 turn, and try again.  Repeat until you successfully deprime the case.