Seat Die — Plug Depth & Crimp Adjustment

Getting the seat die dialed in correctly is one of the most important steps in producing accurate, consistent ammunition. The process has two distinct phases — setting seating depth first, then adjusting crimp — and it's critical not to do both at the same time. Follow the steps below to get it right.

1. Find the Crimp Groove With dummy brass in the shell holder, bring the die down until you feel resistance — this is the brass entering the crimp groove. Back the die up one full turn to ensure you won't accidentally crimp the case while setting seating depth.
2. Adjust the Seat Plug Place a bullet on the case mouth and run it into the die. Adjust the seat plug up or down until the bullet is seated at the correct depth. For 3-die sets, use expanded brass for this step.
3. Verify with Measurements Measure the overall length of the loaded dummy round and confirm the bullet is seated deep enough per your load data. Once the seating depth is correct, back the seat plug up toward the top of the die — this prevents the bullet from being seated deeper while you adjust the crimp in the next step.

1. Bring the Die Down One Full Turn From where you had it backed off, screw the die down one full turn. Run the dummy brass through and test the crimp.
2. Test the Crimp After crimping, try twisting the bullet back and forth and pulling it in and out with your fingers. The bullet should not move at all. If it moves, the crimp is not tight enough — adjust the die down further and try again.

1. Return the Seat Plug to Position Once the crimp is correct, screw the seat plug back down until you feel it make contact with the bullet. This is your final seating depth position.
2. Lock Everything Down Tighten the die lock ring and the seat plug lock ring. Your seating die is now fully set and ready for production loading.