New Giraud - Trimming/measuring case length help

[craigkim]

Well, I got my Dillon swage and my Giraud trimmer. I proceeded to tackle the heap of brass that I had previously cleaned, deprimed, and resized.

Interestingly, I learned to run the swage pretty fast. I could do about 14 cases per minute. You have to have total continuity and economy of motion and use both hands. Very nice.

The Giraud leaves the cases looking pretty awesome, but that's about as far as I have gotten.

Where I am hitting a wall is that I cannot get my cases trimmed to consistent lengths. I am able to trim them pretty effectively and check them on my Dillon headspace gauge to see that they do or will headspace properly, but I am unable to get the lengths to vary less than about 10 thousandths of an inch. The brass is all mixed with the majority Lake City and was fired through a handful of AR type rifles. I used a Redding full length sizing die on all of the brass on my Dillon 650.

Some of the brass is shorter than my trim length of 1.750 and I set that aside to mess with later. The rest of the brass I began to run through the Giraud at 1.750. You can easily tell which ones are being trimmed and which ones aren’t, so it’s easy to cull the ones at less than 1.750. What is bothering me is that the headspace on the trimmed cases looks good, but when I take my calipers and measure the cases at the end they are anywhere from 1.750 to 1.758 with the majority at about 1.755. I tried sorting some like head stamps and then focusing on those, which allowed me to get it down to 3-4 thousandths variation in total case length. This still didn’t seem that awesome to me. How much variation in case length is acceptable? Giraud says that you should be able to get it down to about 2 thousandths. What am I doing wrong if anything?

I know that the Giraud trims the case based upon the shoulder, or headspace, so I think that my shoulders must be uneven and uneven in such a way that my full length sizing is not uniforming them. Another way to say it would be that the headspaces will be uniform, but the cases will be slightly different lengths. Can I or should I remedy this? Is this because the brass has been fired through multiple rifles which alter the shoulder differently?

I’m actually pretty frustrated by this.

 

[17 squirrel]

First, have you watched some YouTube videos on adding a rubber band or spring to you new swager. It also helps speed things up.

My first guess is your shellplate needs to be snugged up, and check that your sizer dies locknut is tight. I would believe that's were you are having problems.

Do you have a single stage press you can size a handful and measure them ??

 

[craigkim]

I saw that with the rubber band, but I think that guy was slower than I was. I timed myself and I did 100 cases in 6 mins. Standing at the machines 7 oclock position, I would load a case with my right hand, flip it down with my left and then continue that motion to pull the handle, then back up with the left to flip up the case and pull it off to be dropped into the swaged box, during which time my right hand was picking up another case and then bringing it to the seating stem. It looked like "wax on wax off".

Anyhow, I thought that too! I checked my shell plate and tightened it down as much as I could and still have it rotate. I even thought about taking out the indexing device so that it WON'T advance and then just running the shellplate ALL the way down to effectively make it a single stage with no shell plate play. As an experiment, I decided to resize some of the trimmed cases and some new ones that hadn't been trimmed. I was running the sizer die down to the point that it was making pretty solid contact on the shellplate and I am using the Dillon billet toolhead, if that means anything. No real improvement/change in case length variability in so doing either in previously untrimmed or trimmed cases. The lengths changed by about 1 thousandth at most. I was really hoping I could just resize and that would be it.

 

[17 squirrel]

Are you sure that the shorter cases were not shorter to begin with ??
In saying that the trimmer never touched the neck to begin with.

 

[craigkim]

Are you sure that the shorter cases were not shorter to begin with ??
In saying that the trimmer never touched the neck to begin with.

Great question! YES. It is very obvious when you are trimming when the trimmer is NOT trimming a case. I had a lot of shorter cases that were definitely in the 1.742-45 range and I separated those completely out after trying them in the trimmer. They also show short on the Dillon headspace gauge, where the case mouth sits below the gauge. I was only expecting results in the cases that were longer than 1.750 which would be indicated by them grinding upon entering the trimmer. I would also then take them out and try them in the head space gauge, in which they lined up perfectly and evenly in every case. The Giraud is precise from my observations there. It was when I took my calipers and measured the entire length of the trimmed, greater than 1.750 initial length cases, that I would find that they varied by several thousandths.

I tried resizing those, then retrimming, with less than 1 thousandth change in overall case length in any case. SO, the difference is in the length of the case body at that point.

 

[tat2clod]

I found when First starting with my Giraud trimmer part of the inconsistency was me, may not be your trouble but had to sacrifice a few readjusting the length then it just became repetition. Once you get it lined out consider your brass stockpile history as hours are minutes with a Giraud.

 

[17 squirrel]

I'm curious what a few other guys opinions are here.

When you take your mic and use some sort of comparator on the shoulder after sizing are your cases the same lenght, say + or - a thou , minus the neck..

I would bet its because of the press or maybe you are not applying the same pressure to the press handle.

Is your press and bench ROCK SOLID.....

I do understand what equipment that you are using, I have the same equipment , a few Dillon presses and I trim with a Giraud.
The only difference is dies, for BS inchangable rounds I use a small base die and match ammo I use Redding Competition bushing dies.
And most of my sizing I do on a old Rockchucker.

 

[tat2clod]

17 squirrel my Giraud bought used is very consistent you maybe onto something here with some deviation in the pressure that's being applied could very well affect the length?

 

[craigkim]

First, have you watched some YouTube videos on adding a rubber band or spring to you new swager. It also helps speed things up.

My first guess is your shellplate needs to be snugged up, and check that your sizer dies locknut is tight. I would believe that's were you are having problems.

Do you have a single stage press you can size a handful and measure them ??

You figured it out right away squirrel!!!!, but I don't feel bad about needing help, as it wasn't immediately intuitive. Basically, your questions put me back to work on the right path, which was that the sizing die wasn't fully bumping the shoulder.

I finally decided to try running the die down farther than I had before.... like just push the limits. I checked the shell plate and it could not be more snug. I WAS running the shell plate up and then tightening the die as tight as I could by hand, then lowering the shell plate and adding maybe a 1/4 turn. That wasn't enough. Tonight I went another 1/2 turn which was as much as I felt would let the press even close! Instantly, I was getting 1.749-1.750 on all the brass sized this way. It seems very aggressive and not mechanically sound. I mean I can actually feel the press sortof reach a stop point and then I keep going with the handle to finish the stroke. I backed it out about 5 degrees and now I get EVERY case, regardless of head stamp, going from sizing to trimming and coming out 1.750. Did 5 in a row. Actually I lie a little, I had a couple that were too short to begin with, but anything that started longer than 1.750 got perfectly trimmed back to 1.750. AWESOME!

I am surprised I need to run that die so hard onto the shell plate.

Thanks for everyones help!

 

[craigkim]

Oh, also I am using the Redding plain Jane full size die with the carbide insert. I like their micrometer dies, so I went ala carte and paired that die with the Redding micrometer seating and crimping dies. I don't have a bolt gun, so I didn't think a neck sizer would help me.