by: Larry Medler
This may or may not apply to you. Lately I have been measuring the force it takes to seat bullets and this set up uses a flat load cell plate on the press ram and not a shell holder. This set up as been working fine for me for the past couple or so years on brass that had been reloaded a few times before measuring the bullet seating force. However, I had to start some new brass and noticed that the cartridge would stick in my Redding Competition Seating Die. I was also noticing some scratching on the bullets after seating. So I decided to take my Redding Competition Seating Die apart and clean in. Wow, what a mess inside the throat of my seating die. I have not been using moly coated bullets for some time but this build up sure looked like moly build up in the seating die. I must admit that I have not very obedient about cleaning my rifle seating dies. So this is just a note to all past and present moly coated bullet uses, you may want to check your seating dies for moly build up. All of my seating dies had some build up. The following picture shows the moly build up in my Redding Competition seating die for my 221 Fireball.

Now for rest of the Story!


That is the first part of this story, check and clean your seating dies. The second part of this story I will keep short. The real story could be a book. I measured the hole in my Redding Competition Seating Dies and my Wilson in line bullet seating dies while cleaning the seating dies. I measured the holes in the seating dies using gage pins. (Actually I was using the gage pins to test if I had hole in the die cleaned) The bullet seating holes in my 308 and 6XC Wilson dies for were one thousandth larger and two thousandths larger for my 223 seating die than the bullet seating hole in my Redding Competition seating dies. Interesting? The Wilson Dies do not use a shell holder. They just have a small plate with a hole in it for primer clearance. After cleaning my Redding Competition Seating dies none my older loaded ammunition would stick in the dies.

However the new brass which I just turned necks on, most of those loaded cartridges would stick in the Redding Seating Die. What causes this? At first I thought my brass which was once fired was sticking in the Redding Seating Die. This brass could have been re-sized one more thousandth. The re-sized brass shows a little bolt closing resistance on some cases. However, the re-sized brass does not come close to sticking in the seating die. The bullet also slides easily through the seating die. Yet seated rounds stick big time. Cause: inside neck wall and outside neck wall not on same center line. The inside neck circle is off center by variation in neck wall thickness. So after turning the necks the hole in case for bullet is still off center a little. That little bit will cause the seated bullet to rub on one side in the seating die. When using a shell holder on the ram the case is easily extracted and any sticking is not noticed. Some rounds just feel different than others.

The Redding Competition Seating Die is very sensitive to any off center bullet conditions with the die seating hole very close to the bullet diameter. So variations in neck wall thickness may be enough to cause one side of the bullet to bind in the seating die and require that a shell holder be used to remove the cartridge after seating the bullet. The Wilson dies are opened up some so most will not stick and the ones that do may be easily removed with a screw driver. That is what the relief cut is for in the bottom of the Wilson Die.

However there might be another use for the Redding Competition Seating Dies and Wilson Seating Dies. If you have both for one caliber, you could use them for a Go and No-Go gauges to check cartridge concentricity. While the die is not in the loading press, simply place ether die over the loaded round so the case shoulder bottoms out in the die. First check some prepped brass without a bullet to see and feel how the empty brass will slip easily in and out of the seating die. Also note how far the brass goes in to bottom out on the case shoulder. Then do the same with a loaded round. Just using your hands press the cartridge completely into the seating die.

If a loaded round sticks hard in a Wilson die – Not very Good

If a loaded round does not stick in a Wilson die and sticks in a Redding die – Okay but not great

If a loaded round does not stick in a Redding Competition Seating Die – About as good as it gets.

Note: Neck turned brass after fire forming should all pass the Redding Die Test. Cases with unturned necks, I am guessing that most of them would show some sticking in the Redding Die. The one standard seating dies I have the hole for the bullet is five thousandths greater than bullet diameter and could not be used to test for concentricity.

Larry Medler