Help-Can't get proper headspace

[Birddog1911]

Trying to reload .223 for my AR. I'm using a Dillon 550, Dillon dies, and a Wilson case gage.

Checking the brass prior to sizing, the rim is just ever so slightly over the top "lip". I can't size the brass to get it between the two limits. If I go too far down with the die, the rim sticks out further on the gage from where I start.

I seem to have found the best dimension I can achieve, but it is still just ever so slightly above the upper "lip". Pretty much where it is prior to sizing. I don't get it. Should I try backing the die out to just where it deprimes, and see what it does there? I tried backing the die off a bit, but it doesn't seem to have sized enough.

I've tried inserting the case backwards in the gage to check the rim, but they're clearing fine.

 

[fguffey]

I will get you some help.

I do not have a shortage of presses, color or models. If I was having trouble sizing a case in a Dillon I would move the die to a (strong) single stage press, install dies and shell holder, adjust then size 20 cases. After sizing cases in the single stage press I could check to determine if the cases would chamber, if the cases did not chamber I would then measure the cases for length from the head of the case it's shoulder.

One thing ( mistake) can go wrong on the Dillont is failure to secure the shell plate to the top of the ram, then there is the shell plate itself, the deck height of the shell holder/plate is .125 thousands, it is possible for a shell plate from Dillon to have different deck heights, this goes unnoticed because most never measure, the problem goes unnoticed because a deck height of less than .125 will result in a short case from the head of the case to it's shoulder, meaning the only problem a reloader is sure to notice is a case that will not chamber.

If you ever wonder if the Dillon flexed measure the distance from the shell plate at the rear to the press frame with the ram up and no load, then size a case, while the press is under a load measure again, If you want to know if the case is whipping the press get a feeler gage and measure the gap between the top of the shell plate to the bottom of the die, if there IS a gap the case is not being sized (for what ever reason), if you have the luxury of new unfired cases start over, the difference could be difference between sizing fired cases and new cases.

Call Dillon.

F. Guffey

 

[fguffey]

The Wilson case gage can more than measure above, at, between and below, after you purchase a feeler gage you can acquire a straight edge or use something that has a straight edge. When measuring from the head of the case down to the base of the gage the relloader can determine the protrusion of the case above the gage in thousands, when the case head is below the top of the gage the reloader can measure from the top of the gage down to the case head in thousands.

As to reversing the case by inserting the case head into the Wilson gage, the case head is not sized, back to the deck height of the shell holder/plate the shell holder prevents the case head from being sized.

F. Guffey

 

[steve4102]

If I go too far down with the die, the rim sticks out further on the gage from where I start.

Believe it or not this is normal. You do not have the die adjusted down far enough. You are sizing the case body, but the die is not making contact with the shoulder of the case. Follow Dillon's instructions and keep adjusting the die Into the press until the case fits the gauge. Yes even if you come to a point that the case has grown. keep going past that point and the die should eventually contact the shoulder, a little more and the shoulder will be bumped back to fit your gauge.

 

[Seedtick]

Here's more good info....

Shoulder Bumping & Case Head Clearance

HTH

Seedtick

 

[GLShooter]

I'll play salmon here. This is what I would do and like gentleman with multi-colored and types of presses I am in the same boat!!

I would take that case gauge and set it up on my book shelf as a nice little "would not buy again" knick knack.

Order up an RCBS Case Mic set for 223. Get that puppy in and follow the directions. I'd size my cases 0.003 smaller than the fired size and call it good.

The case gauge you are using is a generic. What if you have a long chamber? If you size down perfectly for the gauge you may, in fact, be over working your brass. If you have a SAAMI minimum chamber while it will "fit" it may need a tad more clearance to run 100%.

I use the RCBS Case Mmic on 95% of my rifles and have had great success with them. I also have used the Stony Point set up (now Hornady) and had good results. You simply must have a tool that will give you a number to work to or from IMHO.

Greg