Loading Press Induced Runout

[titanxt]

Hello all! Tonight I received my new set of Redding sizing dies with the bushing insert for .223 Rem. After cleaning up the die, I properly installed it into my press and made a few adjustments. I found a piece of fired brass that had hardly .001" of neck runout and put it through the sizer - it came out with about .004" of runout. I then placed a bullet on the case and pressed it into the seating die. The end result... about .006" of runout.

What I believe is happening (and I could be way off base and have yet to get a rubber ring or two to place under the die as some have previously suggested) is that the tool head has way to much play in it. Here is a picture of what I am talking about. This is a random picture off of Google, but you can see the looseness between the tool head and where it slides into the press.

When you push the ram upwards, the tool head rises up just a bit as the cases put upward force against the dies. I am wondering if this small amount of play is what is causing the runout in my loaded rounds??

The Dillon is a great press for loading handgun ammo, as well as some of the rifle rounds I have used for hunting, but I am curious how to overcome this issue in order to load more precise ammunition.

Your thoughts?

Thank you!

Andy

 

[BoydAllen]

What is the difference in the neck diameters of your loaded and fired necks? Are you using an expander?

 

[jonbearman]

Boyd I think he said it was a bushing type s sizing die but did not say what type in respect to neck or full length. I have a Dillon 550 and if I am using good dies the runout isn't anywhere near the .006 he is getting and I use an expander ball to boot.

 

[michaelnel]

Unique Tek has some products to address this, for instance the Whidden CNC machined toolheads:

http://www.uniquetek.com/site/696296/product/T1333

 

[jkohler]

Do you have the bushing tightened down all the way or are you allowing it to float some? They should float some

 

[titanxt]

I have it set as close to the instructions as I could and that is tighten it down and the back it of 1/16th of a turn. Should I do more?

Thanks!

Andy

 

[titanxt]

Boyd,

The fired case OD of the neck is .2520, the loaded case neck measures .2465.

Thank you!

Andy

 

[titanxt]

I forgot, I am not using the expander ball at this time.

Thank you!

Andy

 

[jkohler]

Just make sure it is floating some. Give it a shake and see if you here the bushing rattle. You could try and turn the bushing over for giggles

 

[BoydAllen]

If you are using .002 neck tension, your bushing die is reducing the neck of the fired cases .0075, which is not the best situation for bushings.

Just for an experiment, try the dies in a single stage press that has produced relatively straight ammo.

Because of the extension of the angle of a cocked neck, loaded rounds, measured on the bullet typically have more runout than the sized case before loading.

 

[Scott Harris]

I get between zero and .001 runout on my Dillon as measured on the bullet just in front of the case. This is achieved by:

1. using a Whidden/Uniquetek ToolHead that floats the dies
2. using custom non-bushing sizing dies that produce zero runout sized cases.
3. My Forster/redding competition seaters introduced a small amount of runout.....making a custom seater might be next on the list.

Long story short, the Dillon can produce perfect ammo when setup correctly. Your die quality is very important and has a huge effect on runout...

The photo below shows my four stations: F/L non-bushing sizer, mandrel, powder, and seater. It's hard to see, but the die lock rings are captured but floating to allow the dies to float. Also notice that the toolhead is screwed tightly into the press to fix it in place.

 

['Freak]

“Squaring the dies” is straight out of Sierra’s 5th Edition, pages 153-154:

“….. in many instances, there will still be some misalignment between the ram/shell holder and the die body.
Squaring the dies can help to reduce or eliminate this misalignment, resulting in improved concentricity and better accuracy.

To square your dies, start by following the adjustment procedures outlined above, up to the point of locking the die. Rather than merely snugging the lock ring down against the top of the press and locking it, the dies are squared by lowering the ram slightly, and placing a flat machined washer between the die body and the shell holder. Raise the ram slowly, until the washer is putting light to moderate pressure on the bottom of the die. This will remove the play from the threads, while the flat washer helps to hold the die body square against the shell holder. Maintaining pressure on the die body, now lower the lock ring, and lock the die firmly in place.”

Buy the cross-bolt style die lock rings and be rid of any lock rings having a set-screw that is directed straight in at the die’s threads and whilst being tightened, potentially shoving the die body off center.

The same voodoo applies while aligning and locking down expander/de-cap stems and such. When pulling the expander ball back through the sized neck, stop the ram’s down stroke with the expander ball captured about half way through still inside the neck. Via the ram, apply a touch of upwards pressure to the case and so on to the expander ball so it’ll shove the slop out the stem’s threads, topping out the stem in the die body. Hold what you got whilst tightening the expander/de-cap stem lock nut.

You can substitute an o-ring for the wire shell holder retainer clip. An o-ring will allow the shell holder more freedom to move and better align the case with the die body.

 

[Joe Salt]

You guys sure have a lot of time on your hands, trying to make a silk purse out of a sows ear again. I have two Dillon 550's one does 44 mags and the other 45 ACP. If you want straight use an in line press there are a lot of great ones out there.

Joe Salt

 

[CatShooter]

You guys sure have a lot of time on your hands, trying to make a silk purse out of a sows ear again. I have two Dillon 550's one does 44 mags and the other 45 ACP. If you want straight use an in line press there are a lot of great ones out there.

Joe Salt

+10

You can not straighten an improperly bored die by playing with the lock ring - it is just not mechanically possible.

If your die is bored off center or off axis, replace it.

And put it an "O" frame press of substance that was bored in one pass (ALL of the major presses are bored in one pass)

 

[Patch700]

One of the interesting things that come about when people try to make a "silk hat out of a sows ear" is that it brings to light what it is that really needs to happen in order to make something concentric ...

As mentioned above with respect to the removal of the spring clip from the press ram , this in essence is allowing the shell holder to move in and out from the centerline of what is supposed to be a straight line between the die and the case..To take that one step further , if the shell holder is then turned so the opening is 90 degrees to the opening of which it was slid into the ram then the case can center itself both laterally and to and fro. (See the coaxial press)

Now you can self center something all you like but in the end what that is telling you is that you are indeed trying to alleviate some short comings in the concentric department within your components.

Start with good quality components and you can save yourself some playing around and give yourself more time to contemplate why it is that nobody has come up with a way to attach a small arbor press to the top of a single stage so one can run his cases fully up into the sizing die with the bushing removed and THEN be able to press the bushing down onto the neck whilst it's being fully supported by the die lol.

carry on lol.

 

[CatShooter]

Start with good quality components and you can save yourself some playing around and give yourself more time to contemplate why it is that nobody has come up with a way to attach a small arbor press to the top of a single stage so one can run his cases fully up into the sizing die with the bushing removed and THEN be able to press the bushing down onto the neck whilst it's being fully supported by the die lol.

carry on lol.

The Redding Competition Neck sizing die does that in one pass. No arbor needed. If a bump is needed, do it with a forster in a separate run... easy peasy, off the rack dies.

 

[Joe Salt]

Cat shooter I see you are doing about the same thing using the Redding Competition die on a separate pass. I first use a die made with my reamer to do the bump then neck size! Works For me. I have two RCBS A-4's side by side with each die set up.


Joe Salt

 

[BoydAllen]

Of course if a given procedure works for you, it is by definition correct...however there is an issue that your method does not address, and for some it will have to be, tightness at the base of the case.

A friend, who does his own barrel work, built a .243 AI, but did not want to spring for the cost of the dies, so he built a bump die using his chambering reamer, and sized his necks with a collet die, which worked, up to a point. Of course he had gone to the Ackley to gain velocity, and loaded to pressures that were consistent with that goal, which took him to the "I told you so." situation that I had cautioned him about at the beginning of the project, when he explained how he was planning on handling sizing. His cases became tight at the back. Since he is a friend, and had done me several favors in the past, I located and bought an old, non-carbide, RCBS .45 ACP reloading die set, gutted the FL die, and gave it to him with the instruction that he could use it as a ring die, to size the bases of his cases, but that it might need some adjustment by polishing out to get the amount of sizing correct (which was the reason for my choosing a non-carbide set). It worked perfectly, and since then, other friends have done the same thing, to deal with the situation of having a chamber that is too small for their FL die. Of course this can be avoided if one first measures cases that have been sized by ones FL die, before ordering a chambering reamer, so that the reamer will cut chambers that produce fired brass that the die can size to the desired fit. As I have written before, well used cases that are at their maximum work hardening, are what one wants to use for this, because they will size to the largest dimension that the die will produce, due to their greater spring back.

 

['Freak]

The fit betwixt the 7/8-14 threads cut on and in even the very best die and press combinations available leaves plenty enough room to result in die alignment error.

 

[CatShooter]

Cat shooter I see you are doing about the same thing using the Redding Competition die on a separate pass. I first use a die made with my reamer to do the bump then neck size! Works For me. I have two RCBS A-4's side by side with each die set up.


Joe Salt

Joe... I very rarely bump, and almost never FL size - I find that neck sizing works fine for me (I don't shoot free recoil!!).

I shot a bunch of W-W 22-250 cases ~45 times each, and FL sized them twice (and that was because I rebarreled several times and they wouldn't fit the new chambers)- the rest of the time they were necksized.
My .220 Swift, and my .224 Rem cases both have less than a thou of run-out when I use the Comp Bushing Neck sizer, and they are NOT tight neck or no-turn chambers.