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Dillon 550 question and headspace confusion

TheGerman

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  • Jan 25, 2010
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    2 things Ive run into that I figure you guys would know:

    On the Dillon 550, I recently got the electric trimmer and the trim die. Besides this being a total PITA to get it set up for a specific trim length, is the trim die also a FL sizing die? If so, would it be smarter to make a separate tool-head with the decapper (to pop out the primer) in station 1, and the FL sizing trim die + trimmer in station 3, or would this overwork the brass as it will literally be getting sized twice? Trying to figure out how to get the primers out as it seems I would be sizing the brass twice regardless. Or?

    Also, does anyone have a better way of setting the trim die and trimmer other than screwing the trimmer and its locking ring slightly up or down and hoping you get what you're after? Really eats alot of brass this way.

    Secondly, I have a set of Wilson Headspace gauges for each caliber I reload for. I started something different recently in that I now measure each rifle's chamber with a Chamber Length gauge as well as measure the shoulder on a fired case. Since I now have each rifle's specific chamber length and what depth the sizing die needs to be to bump the shoulder, doesn't this replace the need for the Wilson gauge?
     
    Easy set up here. Just adjust the die independently for HS, as if it were your sizing die (which it essentially is), and then add the trimmer motor and adjust it second. The biggest problem I have with these is that the reamers they apparently use for these dies seem to be the same ones used for normal F/L dies. This makes the neck O.D. far too small, and they need to be opened back up with a mandrel or expander ball to get the correct neck tension. I had the machine shop hone the necks on all of my trim dies to the same dimensions I use in Redding bushing dies for each respective caliber. I haven't bought any of the Dillon trim dies in some time now, and they may have corrected this situation, but it's something to check for the first time you set one up. Other than that, it's a pretty good system.
     
    I have .223 and .308 trim dies and I have them setup with the real FL size and decap in station 1 and the trimmer at station 3. I havent noticed the trim die closing the necks down at all. Bought my setup in 2010 I think.

    And like ksthomas says setup head space with the die and then mess with the trim length. ALWAYS start way long on trim and dial down. I think the dillon instructions say to run the motor down until the cutter touches the die and then back off like half a turn. thats always way to much IMO. I think I do 2 turns off and I run a piece. 1/8 of a turn in at most at a time and run it again. I generally can get my motor setup with 1, maybe 2 pieces of brass. Takes a bit of time to get set right without ruining brass. I can generally get the 2.005 trim length as well. I generally run 1000 pieces of brass at a time when doing prep(in 100 round batches) so I only go through trimmer setup once a year maybe. For .308 I can get generally 3 loadings without trimming.
     
    I just did some tonight on mine. The way I adjust the trimmer is to adjust the die first and the put a FL sized/trimmed piece of brass in the die and screw in the trimmer until the blade barely contacts the mouth of the case. Be sure to check to see that there is space between the blade and the die. Start to trim and lower little bit at a time until gtg. Tonight, after loading to the brass it was gtg with no further adjustment.

    As far as setting up a dedicated toolhead, I've been planning on just using a universal recapping die on the first stage. I might reconsider that after what is mentioned about neck tension...
     
    Put an rcbs universal decapping die in the first stage. The trimmer die is a full length die so adjust with a case headspace gauge first. Then insert a previously trimmed case (I use a forster trimmer for this) in the sized/trim die to the bottom of the stroke. Then screw the trimmer down on to the case til it touches the trimmed case mouth. Tighten the lock ring.

    Because the sizer is the trim die there is no expander ball to bring the neck back after it is sized. Now on the last stage put in a Lyman "M" die to expand the neck and very lightly bell the case mouth for easy bullet seating. This way you end up with properly sized (only once), trimmed, decapped and mouth expanded brass. Just inside/outside chamfer the case mouth and clean up the primer pocket (if that's one of your steps) and you're ready for primer, powder and bullets

    Hope this helps
     
    So many ways to get to the same end result.

    I was like Kevin above, the die way undersized the neck so I opened it up.

    I use the Lee decapping die in 1st station, the trimmer in the 3rd station and sometimes an "M" die in the 4th station.

    You might find that the trim die just doesn't resize the case body enough as I did for some of my chambers so sometimes I have to run them thru a standard die in which case, I do this before going to the trim die. This is where honing out the neck portion of the trim die really saves me from over-working the brass.

    Someone on a different thread alluded to the "M" die causing more run-out for them but that hasn't been true for me. I get less run-out with the "M" die than with the expander mandrel on the decapper that comes with standard dies.

    Also as above, set up the trim-die to correct headspace then work on the trim length.