Dillon Precision Products RL550C, Assembly And User Instructions Manual

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Setting up the Rifle Seat Die: Place a sized case in Station 3 (case can be primed and charged). Cycle the
Operating Handle down. Screw the Rifle Seat Die down until it touches the case and back the 7/8-14 Threaded
Die Body up two turns. Lock the Die Lock ring in place with a 1” Dillon Bench Wrench while holding the die
with a 7/8” end wrench. Loosen the 5/8” Seating Stem Lock Nut and back the center 9/16” Adjustable Seating
Stem up 3 turns. Place a bullet in the case mouth and lower the Handle. Carefully screw the 9/16” Seating
Stem down until it contacts the bullet. Raise the Handle, remove and measure the COAL of the cartridge with
a dial or digital caliper. If the bullet is not seated deep enough, screw the 9/16” Seating Stem down 1/8 of a
turn at a time. As a guide, one full turn moves the Seating Stem ~.050”. A ¼ of a turn is about .012”. Repeat
these steps until the COAL is correct. Tighten the Seating Stem 5/8” lock nut while holding the 9/16” stem
from rotating with end wrenches with a cartridge in the Die with the Handle down). (A quick method for pre-
setting the Die is to place a previously loaded “good” cartridge in Station 3 and adjust the Die down until just
touches the case and adjust the Seating Stem down until it just touches the bullet.) Again, check the COAL and
adjust as necessary.
8.6 Station 4--Bullet Crimping
8.6.1 Crimping is the final operation in the reloading process in Station 4. Crimping removes the belling of the case
mouth from the previous neck expanding or belling step. Crimping provides added friction for “holding” the bullet
by the case. Dillon recommends the crimp operation be separate from the seating operation and provides
independent crimp dies in the Dillon 3 Die sets.
8.6.2
Dillon Pistol Crimp Die with removable Crimp Insert:
8.6.3 Dillon Rifle Crimp Die:
8.6.4 There are two types of crimping--the roll crimp and the taper crimp. In general, taper crimping is used for semi-
autos with rimless cartridges and roll crimping for revolvers with rimmed cartridges. Excessive crimping can
“buckle” the cartridge case as shown below.
Roll Crimp
Taper
Crimp
Cross section of
Rifle Crimp Die
Measuring Rifle COAL
Cross section of
Pistol Crimp Insert