Lee Collet Neck Sizer affecting shoulder dimension

[Argon3119]

Hello members, I have been using you site as an excellent resource to answer my questions for some time now. I'm doing my first post because I have not found anything about this particular problem.
In the last year I have been using a 223 as a cheaper way to work on fundaments and using a LCD for all my sizing. Some of my brass is now getting to its 4th cycle and I thought it is time to take some measurements before FL sizing.
Post firing my bump gauge reads 2.545". After sizing with the LCD they are reading .005 less. This is more than I adjust the FL sizer to bump the shoulders on my other calibers.
I thinks I have the die adjusted properly so that the RCBS press doesn't cam over.
Thoughts? The brass is currently chambering fine.

 

[jonbearman]

Does the collett die leave marks in the neck while resizing?

 

[jlow]

Sorry, but your numbers don’t make sense. You say “Post firing my bump gauge reads 2.545".” SAAMI spec for 223 gives an OAL length (base to melpat) of 2.2598” so a bump gauge which measures from base to the shoulders cannot be 2.545”

 

[Concha]

What kind of rifle are you shooting?

 

[ReedG]

I assume you are measuring the length from base to shoulder, using some type of accessories to your caliper. You probably didn't zero out the caliper to account for the length of the accessory. The only .223 I'm currently loading for is a Tikka 595MS and it gives a base-to-shoulder length of 1.4350 using the Hornady accessory.

I am a long-time user of Lee Collet Dies, in calibers from .22 Hornet to .308 WCF, and have never seen a difference in the neck setback from using the LCD. If, in fact, that is happening with your set-up, the only thing I can think of is that the collet is topped out in the die and the press is still pushing the case further into it and, thereby, pushing the neck back. If your RCBS is a Rock Chucker, it has power enough to do that with a barely perceptible tension on the lever. The Rock Chucker has enough leverage to resize steel cases if you wanted and 10 or 12 thousands of brass are of little consequence to it.

Check your neck diameter when you start, then run a case in until it stops and just apply a slight pressure on the lever, and check your neck diameter again. Years ago, when helping another shooter adjust his RCBS to properly use LCD in .22-250, I found that just the weight of my arm on the lever was sufficient to size the neck.

The RCBS is a bear of a press, for sure, and there are plenty of tasks that can use the leverage multiplication it offers. Keep in mind that the press has enough power to swage bullets and all you want to do is resize the thin little neck of a .223 case by a couple thousandths. Any effort whatsoever on your part when pushing the lever is more than enough to neck size.

 

[gotcha]

I agree with REEDG. Put a mark on your LCD at the 6 o'clock position with a magic marker. Size the case using light pressure (just a light bump at bottom of stroke) Measure shoulder set back. Now back die out 1/8th turn and size a new case and compare. Continue 'til shoulder set back disappears........... Check neck diameters on each case to insure consistent neck sizing. Let us know how this works as there are other remedies. But 1st dis-assemble LCD, clean thoroughly, lightly lube the outside of the collet fingers with grease and re-assemble.

 

[Argon3119]

Thanks gotcha and Reed for your insights. My first suspicion was also that I was bottoming out the die.

I just ran a few cases through with the die backed out and trying to apply just enough effort that I cannot seat bullets freely. To get the usual .002" tension was still resulting in .004-5" setback.

I am measuring this with a sinclair bump gauge. I am not sure exatly what point in the shoulder it is making contact. Perhaps it is bearing at 2 different points on the case when measuring pre and post sized? I cannot measure any changes on other parts of he case (diameter just below the shoulder).

The neck sized ammo is shooting to my expectation out of this rifle, what prompted me to notice this was taking fired case measurement to setup the FL die. Perhaps when the cases are tough to chamber I'll just set that die to .003" setback and keep fiddling with the LCD.

-Jon Edwards

 

[masterblaster1]

I used to use grease on the fingers of the collet, I have recently started using lighter fluid, I felt that the grease turned into a sticking agent every.

 

[Heavies]

The collet die should only be sizing the neck. If it is pushing the shoulder something is amiss. The design of the collet die doesn't touch the case body at all. Make sure that the press doesn't cam over when the die is doing the neck sizing. Very little force is required to size necks, and if the press cams over you will destroy the die in short order. Either don't cam it over, or just barely, for consistencies sake.

 

[bsekf]

With a standard cartridge you should have no trouble, just follow the directions. The die has to be touching the shell holder for the die to work. I had a AI version the would hit the die in the shoulder area but it then would not chamber. I just put a shim (washer) over the case so the washer contacted the die base. There is nothing in the collet die that would re-size the shoulder, just damage it.

 

[Argon3119]

The washer idea had occured to me today also as I remembered reading about some people using washers to intentionally create an unsized "doughnut" at the base of the neck. I played around wih some feeler gauges as shims and found that a .012" was what it took to leave the comparator reading unchanged.

I also tried a couple of other things without a shim. Smoking the shoulder and neck area revealed no marks below the neck. Then I tried using a larger case to make a impromptu comp (an inverted 270 seemed to settle about midway down the shoulder.) Interestingly, it showed no change in size.

This makes me wonder if the drawing of the neck/shoulder junction during sizing is enough to let the sinclair gauge bear in different ways giving the appearance of sizing. In the meantime it is off to find a very skinny washer!

Thanks,
Jon Edwards

 

[broncman]

Just get a set if redding shellholders and be done!

The set comes with different thickness shellholders so no washer is needed. You can aslo use them to bump to a specific dimension.

 

[shanmoll308]

I think your assumption is correct.The comparator is taking the measurement from a point too close to the shoulder neck junction, which is then affected by the neck sizing process.
A quick fix would be to bore or drill out your comparator slightly. This will result in the comparator taking a measurement from a point further down the shoulder, which should result in more consistent measurements.
All the best.

Adrian

 

[Heavies]

Get a Redding body die to bump the shoulder back and the shell holders to keep them consistent. Use a GOOD lube (such as imperial and the like, I use Mink oil shoe polish paste)and use it sparingly. Don't get any on the shoulder, as this will cause an erratic bump. Set it up to bump .002" for a bolt gun, then use the LCD to size necks. You should size this way ever firing to keep things more consistent.

A note on the Redding shell holders is that they will not leave a portion of the neck un-sized. Only the washer trick will do that with any significance, but in my experience, that method does really do much to affect accuracy in a properly body sized case.

 

[Argon3119]

Broncman or Heavies,

When I looked at the Redding shellholders I saw a set of 5 in .002" increments. I assume that means that it come with +0.000 to +0.008.

I would appreciate input if you know for certain since I just made a trial shim out of .010 sheet metal which was just about thick enough to eliminate my problem.

The Rediding holders may not be enough to eliminate the need for a shim with this rifle/die combination. (Not certain where the source is, savage factory chamber or lee quality control. Two likely suspects.)

-Jon

 

[Multitoes]

I think your assumption is correct.The comparator is taking the measurement from a point too close to the shoulder neck junction, which is then affected by the neck sizing process.
A quick fix would be to bore or drill out your comparator slightly. This will result in the comparator taking a measurement from a point further down the shoulder, which should result in more consistent measurements.
All the best.

Adrian

FWIW:
Maybe mark your case shoulder and spin the case in the bump gauge to see where it is making contact.
I say this because I really like the Sinclair gauges BUT (although my 23 degree (223) is good) I had to send back 3 of the 20 degree gauges because they were machined wrong -- they did not measure on the shoulder properly.
BAD news when loading for an autoloader...

 

[243winxb]

http://leeprecision.net/support/index.php?/Knowledgebase/List

Collet Dies on Rockchucker Press
Posted by on 19 October 2011 01:18 PM
If you are using the Collet die in an RCBS Rockchucker press, or a similar design that toggles over center at the top of the (ram) stroke, this applies far greater force than is necessary to resize just the neck of the case, and can damage the die or collapse the case. To correct this situation, adjust the die two full turns into the press after the die contacts the shell holder with the ram at the top of its stroke, rather than one as in the instructions. This will stop the press before it gets to the toggle over point. With a press without having an over center feature, apply about 25 lbs. of pressure to the handle once it bottoms out to resize the case. On most presses, this translates to over 600 lbs of pressure on the ram.

 

[gotcha]

243winxb, Not trying to be contentious here. However, attempting to put 25lbs. pressure consistently on a small fragile case like .223 will do more damage to the die (over time) then a light cam-over. At least a light cam-over keeps press handle pressure consistent and is no where NEAR 25lbs of force LEE really needs to get its act together in explaining the fine points of die adjustment. Some of LEE's own techs aren't capable of doing more than reading from a cue card. I'd gladly pay $25.00 more for a LCD if it was made by a quality mfr. & included comprehensive instructions. ........ Don't hate me.....please

 

[jonbearman]

I think in this particular situation,I would ask for a new one under their no hassle warranty.

 

[CatShooter]

Broncman or Heavies,

When I looked at the Redding shellholders I saw a set of 5 in .002" increments. I assume that means that it come with +0.000 to +0.008.

I would appreciate input if you know for certain since I just made a trial shim out of .010 sheet metal which was just about thick enough to eliminate my problem.

The Rediding holders may not be enough to eliminate the need for a shim with this rifle/die combination. (Not certain where the source is, savage factory chamber or lee quality control. Two likely suspects.)

-Jon

I own several sets of these - they come with +.002" to +.010" The assumption is that you will already own a 0.000".

There is a 6th opening to put that, or as I do, I put a "minus" shell holder for special stuff.

.