OAL Variation/Whidden Free Floating Toolhead for Dillon 650

[navybowhunter]

OK,


**CAVEAT:  None of the below modifications will void your Dillon Warranty**

I have swapped all my toolheads over to this Whidden free floating toolhead.  They are also "clamped" (come with or without that modification)....Clamped means that instead of using the locator pins on toolhead to secure it, there are helicoils installed in the toolhead and they clamp in with two small allen headed machine screws.

That modification (clamping mod) can also be done to standard Dillon 550/650 toolheads.

The issue I am about to refer to is separate from the clamping modification.

In the attached pic, you will see two vertical pins (one easily visible), one is being utilized by the die lock ring for my seating die.

.308 and 30-06 I have same setup and had realized even tighter uniformity in both concentricity (not caring much about that....but it is good) and also OAL variation.

.223 gave me the run-around.  Set die to 2.258 (2.260 is SAAMI but I set my short line ammo to 2.258" to avoid malfunctions in rapid fire).  I was getting 2.240 - 2.269, wayyyyy unacceptable.

I wound up re-seating and measuring the batch of ammo and segregating the shorter ammo for rapid fire for the match a few weeks ago.

Last weekend I reloaded some 30-06, and again...was amazed at how tight the OAL variation was.  I also noticed that the seating die rose about 1/8" on the seating.  Operating as designed.....which in turn provides excellent concentricity and little OAL variation.

I checked the .223 toolhead again and realized that the die, although it moved some....it had no where near the vertical travel the .308 or 30-06 ones did.

I figured maybe the vertical locator pin on the modified toolhead was off center, turns out the die locking ring (aluminum) was the culprit.  Swapped the die lock ring and now I have much tighter OAL variation.

CAUTION/NOTE to anyone else using these toolheads, or considering use of them.  Overtightening the die lock ring will cause the die lock ring to bind/jam on the vertical travel pin on the toolhead.  If you decide to try these (I hope you all do), you want to be careful setting the tension/torque on the die lock ring screw as it can cause it to torque/jam/bind as mentioned above.

Overall I am now VERY pleased with this setup.

The OAL stuff was baffling me.  Note for all on that:  The seating die could care less about the shoulder on your brass and the trim length.  It is simply measuring from the base of your brass to determine seating depth.

SO....if this ever happens with any other setup/press, (OAL variation in seating) it can only really be 2 things.  Defective die.... or lots of variation in the bullet length.

I did find that today, a batch of 10 69 Sierra Match Kings came out (with die set to 2.258") between 2.258 - 2.260.  I then measured (as others have) the bullets themselves and there is a little variation with the meplats, causing the slight variation in OAL.

HOWEVER, I did also measure those 10 with the OGIVE comprator and every single one was within .0005!

That is pretty damn tight!

FWIW, figured I'd share.

R/
Chris