Wonky rim to shoulder lengths on LC reloading, WTH?

General Firearms Reloading & Ammunition
1

Referencing this thread the discussion started focusing more on the reloading and potential issues rather than the chamber.

Now, I have reloaded 4k rounds of mixed LC brass, most of them on their first and second firings (range pickings from training classes and once fired LC that I bought locally ~ 7k) and have not had a single problem. This last batch of 1200 has given me fits.

All of my cases are run in 2-3 three phases (depending on primer pocket reaming for crimp) on a LeeLoadmaster. I do not just pick 1k cases and load them up. I’ll do a day of nothing but sizing, the next day I’ll ream (if needed), the third day I load what I need, and keep a running can of “Ready to load”.

First pass;
-Deprime with Lee universal deprimer.
-Size and trim using a Dillon RT1200 and .223 die.
-Expand case mouth with Lyman M-die.
-Finished cases are all 1.749 +/- .0015
-Tumbled in clean media to remove lube (99% Isopropyl Alcohol & pure liquid lanolin mix).
My bad, I only check the first few cases in my JP enterprises case gauge to make sure I am within spec instead of random checks as I go.

Second phase - ream primer pockets if needed (decided in pre sort).

Second pass through press;
-Deprime again for the flash hole
-Prime with a Lee sizing die backed off 1 full turn from contact at full stroke to assist in centering for primer - It’s a Lee thing.
-Powder drop
-Bullet Seat
-Crimp with Lee factory crimp die
-COAL 1.200 +/- .002
-All finished ammo is marked with a black band around the case head for ID at the range - I know what is mine, already reamed and on it’s second or third firing.
-Loaded in lots of 200 (1 primer tray full), then random checks on COAL and weight, then a verification on powder drop.

In the referenced thread, there was talk of shoulder spring back. That is a new one on me.

In going through what I had loaded up and some of my reserve, I would have a few that were way out of case gauge spec (.006 only from the last batch), about half were barely over (.002 or less reserve and last batch), and the rest within spec. It’s a random thing. Each lot of 200 after they have been marked, are loaded on stripper clips and stored. I would have one clip that was all good, the next would have a few good, the rest marginal (culled for my 16" middy - has no problem cambering them and going into battery, a little stiff on manual extraction), the next one after that would have 2 or 3 that are way out and culled for recycle.

All of them would drop in and out of the case gauge freely, just varied on the shoulder. The over spec cases would have the case mouth below the min - still 1.749". This is a rim to shoulder issue.

This weekend I am going to strip my turret down, and reset all dies and try again. Right now my size/trim die is bottomed out on the shell plate and I am still can’t get that shoulder bumped back.

Thoughts anyone?

If this is shoulder spring back, how does one compensate? Size twice in the same pass?

2

There should be no need to size twice. A few things will contribute to inconsistent Shoulder bump.

First is work hardening of the neck/shoulder from firing/sizing. Annealing fixes this… although I NEVER anneal .223 brass… Just the big boy cases… .308, etc.

The second thing is uneven or inconsistent case lube. I’ve read that poorly/unevenly lubed brass will yield different shoulder bumps.

I’m running a carbide sizing die and dillon lube (lanolin type) and never have any sizing issues. I don’t ever measure shoulder bump… but I never get stuck cases in the chamber, nor do I get brass that I really have to size back down a huge amount.

Once you get the die in the sweet spot, it shouldn’t give you trouble.

3

How exactly are you lubing?

I’ve got the Dillon lube as well and I did the plastic bag method, but found that the lube got into the cases and caused the corn cob media to stick inside the cases when I tried to tumble the lube off after the trim/size…pain in the a$$ getting that corn cob out!

4

I have a couple of plastic trays that came with Burger patties or some meat of some kind.

Lay the brass in the tray and mist it. I try to keep the mouths and primer pockets from getting sticky.

What I’ve started doing to keep my walnut fast in the tumbler is rolling the brass on a rag to get most of the lube off prior to tumbling the brass again. Keeping fast media in the vibratory prevents a lot of that clumping and sticking.

5

Have you guys every found yourself readjusting your sizing die based on the headstamps you’re working with?

I’m curious because I have some WCC cases that have noticeably smaller head diameters, as in they pop out of the shell plate when priming. I noticed when sizing these cases that they size down smaller (sit much lower in the case gage). Maybe inconsistencies in the brass can cause variation in shoulder bump?

6

Lubing can definitely make a difference in shoulder position. When I was testing case lubes I found that Hornady One Shot (I know, its garbage) lubed brass had more variation and about .003 longer dimension with the same sizer position than the 1:9 lanolin oil/ 99% iso I use now.

I use the Dillon 1200 trimmer. I bought a cheap nonstick cookie sheet ($4.00) and I lay the cases down on it and lightly mist them using a pump sprayer with a fine mist.

The way I remove the lube is probably not for everyone but it works for me. I put the processed cases in a large soup pot and add plain tap water to cover them then I heat the pot to a boil.

The lanolin floats to the top and gets poured off with the water. Then I roll the hot cases in a bath towel and leave over night to dry. If I am in a hurry, I dry the cases in a 200* oven for an hour. There is a very thin film of lanolin left on the brass which protects against corrosion.

I read that when the arsenals processed brass they cleaned it in a acid bath and then washed in soapy water and dried. The soap residue was left on the brass to protect it. My method achieves a similar result with the benefit that lanolin is a much better protectant than soap residue.

7

Absolutely HELL NO!

8

It could be a lube issue. I do the 200-300 in a gallon bag and mix them up for a few minuets.

I’ll try a different approach to lubing.

Never had a problem with the lube collecting media in the cases when I tumble in Walnut.

9

I get clumping bigger than shit in my primer pockets with slow media. I get dust in the necks too.

A carbide dies sizes smoother/slicker so it’s more forgiving on uneven lube.

10

I’m working out of town right now, but I got a 4 day weekend, so I’ll dick around with my press on Thurs or Fri and update.

11

Sometimes you need to reset your dies for different brass. Different brands, and brass that has been work hardened by sizing. It can cause brass to spring back at different rates. Most of the time it is not enough to need to adjust dies but it can be.

The barrel you are using might have a tighter than normal headspace. There are so many different reamers for 556/223 chambers. It could be that a reamer was used that has a little tighter dimensions all around, and that is what is causing the slight issues with headspace.

You now know it is a headspace issue so you basically have two options. One being reset your dies to size to your rifle with the tight headspace. It will slightly over work the brass for the other chambers. Option two you can separate your brass to size the brass for the dmr rifle then size how you normally would for the other rifles. You can either reset your die everytime you size brass for the different chambers. or buy an extra sizing die, and have one set for the dmr then leave the other set for your other rifles.

You should definitely get a comparitor from hornady with the insert for checking headspace. It is a lot easier to set up your die with it rather than a chamber gauge. It will also allow you to size the case to a known dimension. Rather than guessing how far below the lip of the gauge it is. It will also allow you to measure the fired brass so you can see if there is a difference in the fire formed brass from the different chambers. If the fireformed brass from your dmr barrel measures out to be shorter from head to shoulder it will show you just how tight your chamber is.

If you do not want to buy the comparitor i would let you borrow mine with the headspace insert you need to measure the difference in the chambers, and set up your dies. They are not expensive, and each insert will work with multiple rounds. The headspace inserts work with any caliber that uses similar dimensions brass. Like the 308 insert also works with 243 and 7-08.

12

Just a couple of possibles:

The lock nut on the Dillon Sizer/Trimmer allowed the unit to move and it’s out of adjustment.

Some of your brass has a ding on the rim and you are getting false readings with the case gauge. Put them in backwards to see if it’s just the rim.

ETA: Possibly the turret press is worn out or needs the turret tightened down (slop in the unit).

Something I see in 7.62x51 (but never noticed or looked for in .223): As brass gets older the shoulder does not move back as much in the sizing operation. But nothing like a .006" difference - more like .002"

The Hornady Cartridge Headspace kit is handy if you are going for minimum shoulder setback (~.003" for a gas gun). But a case gauge should suffice unless you have a tight chamber.

I lube the hell out of my brass and hit a lot of the case mouths as well (usually with Dillon lube). Tumble in corncob /w Dillon polish for ~45 min - no issues with the media sticking in the neck. I do about 125 at a time in a gallon zip lock.

13

I appreciate the offer. My rule of tool borrowing is If I have to borrow the same tool 3 times, I buy it - caveat - we don’t work in the same shop so that complicates things.

Still all trimmed cases are 1.749+/- so if the sizing die moved out, then the trimmer moved in, and both are tight.

Some of your brass has a ding on the rim and you are getting false readings with the case gauge. Put them in backwards to see if it’s just the rim.

I’ll double check, but the really bad ones are not even making it to the rim, the others the rim is just barely above the shelf on my case gauge.

ETA: Possibly the turret press is worn out or needs the turret tightened down (slop in the unit).

Something I see in 7.62x51 (but never noticed or looked for in .223): As brass gets older the shoulder does not move back as much in the sizing operation. But nothing like a .006" difference - more like .002"

The Hornady Cartridge Headspace kit is handy if you are going for minimum shoulder setback (~.003" for a gas gun). But a case gauge should suffice unless you have a tight chamber.

I lube the hell out of my brass and hit a lot of the case mouths as well (usually with Dillon lube). Tumble in corncob /w Dillon polish for ~45 min - no issues with the media sticking in the neck. I do about 125 at a time in a gallon zip lock.

I might be trying to lube up too many at once. I am half thinking of buying a third tumbler, cut up a few sponges into little tiny cubes, or flat out shred them, and soak those in my case lube then tumble the brass to lube them. I ran across a lubing die at one point (has a felt ring inside that you lube up through an external hole - I can hook up an IV) and use that…nah sounds like a gimmick.

I presume this is the Hornady tool you all are referring to?
http://www.midwayusa.com/product/479704/hornady-lock-n-load-headspace-gage-5-bushing-set-with-comparator?cm_vc=subv1479835

May as well buy it, getting ready to buy a single stage press to set up as a cartridge unloader. Hopefully all the items in my cart will drop in price tomorrow.

Today’s mystery question - OK to re-size primed brass, or write off the primers when recycling the bad rounds? I’m such a tightwad - we are only talking $27 in primers here :rolleyes:

14

I presume this is the Hornady tool you all are referring to?
http://www.midwayusa.com/product/479...vc=subv1479835

That’s the one I was referring to. Works well, but it takes a little experience to get a reliable reading - the case head needs to be set just right - take multiple reading and go with the smallest consistent reading on a given piece of brass. You need a decent set of calipers.

I bought one to see what my shoulder lengths were for a SCAR-H (chambered 7.62x51). I’m now setting back the shoulder .005-.006" instead of .0075-.008" (where I needed to be for SCAR or FAL fired brass to chamber “no pressure” in a .308 bolt gun. 1st time reloaded Aussie 7.62 brass averages ~.0065" and 4th/5th sized is ~.0050".

The type and amount of lube used will change the reading - I got as little as .0035" shoulder setback with #5 brass using wax lube.

FWIW, the shoulder reading for some Federal factory .308 is about .008" below brass fired in the SCAR. My most accurate 7.62 surplus (AFF '91 Aussie) runs ~.0065" below my SCAR fired brass. SA '81 and some RG run about .005".

I also checked my .223 brass: Sized in the Dillon trim die it’s getting set back .0025" - .0030" at the shoulder, which corresponds to just barely under the top edge on my Dillon case gauge.

My RCBS sizer setting read .004" and .005" (possibly related to brass from different chambers - Noveske & DD ). I did not change either die from where I already had them set - but I consider the Dillon setting to be really marginal. (I’m moving to the Giraud Trimmer for .223, anyway and have already gone this route for .308/7.62.)

On pulling your ammo: If it will chamber and shoot I would just separate into two piles. Shoot up the bad stuff for range practice.

15

I got done going though all my loaded ammo.

50+/- that have to be recycled, 440 that are .002 or less over that my 16" middy will have no problem cycling, and probably 500 that are right at max or less which will run in my Mk12 with only a few that will be a little snug on manual ejection.

Still have not tinkered with the press, that is tomorrows chore.

16

Not an expert but I have had the same issue you are dealing with.

In my case it came down to using the RT1200 to resize. Lacking an expander ball you do not get a good shoulder bump with the RT1200. I changed my setup to do a full length resize/bump BEFORE hitting the RT1200 (which is setup only to trim). After that I had no issues.

YMMV.

\S1

17

I love my job, I need my job, I love my job, I need my job, I love my job, I need my job…

Been too busy to enter this project, layoff can’t get here soon enough.

Anyhow, I finally got the recommended Hornady tools for my caliper.

Let me see if I am understanding the procedure correctly;

1 - Take a fired case and measure with the properly installed and zeroed Hornady tool. In my case I get 1.458 +/- .0005 on a 5 case average that was fired from my Mk12.

2 - Run the fired case through my sizing die and measure again, and adjust until I reach the target number of 1.454" (bumping the shoulder back .004")?

I may or may not have any cases fired from my 16" middy available for checking. I am pretty sure that I have already processed (sized and trimmed) all of my reamed and previously fired brass.

Now, given that I don’t want to set up another tooling head for my press for each AR, what would a safe bare minimum shoulder bump for my Mk12 be, that I can still shoot out of my 16" and not over work the case, since the 16" appears to be a touch more forgiving?

And while we are at it, how much of a jump to the lands (bullet seating - bought that attachment too) should I be looking for to get the best accuracy. I appear to be lucky in my M193 since I am pulling 1.4 MOA out of my 16". Right now I am just going with AA’s reloading recommended COAL.

18

Only you can figure that out, but IF the MK12 is your tightest chamber you are good to go. Load a few dummies at the .004 setting; hard chamber in your other guns and see if they extract OK. Save some fired brass from those guns later and measure the net setback for those specific cases.

And while we are at it, how much of a jump to the lands (bullet seating - bought that attachment too) should I be looking for to get the best accuracy. I appear to be lucky in my M193 since I am pulling 1.4 MOA out of my 16". Right now I am just going with AA’s reloading recommended COAL.

This is probably moot if you are loading to mag length - you can’t get close to the lands anyway with a 5.56 NATO chamber. Certainly something to test for, however. Load a dummy way too long and hard chamber by dropping the bolt. Eject smartly and see if it reaches the lands and the resulting COL if it did. (Be sure you don’t leave a bullet stuck in the barrel.)

You can even use a dremil to partially split the case neck to get things a little more sensitive. [This is the poor boy method to find the lands in a bolt gun.]

19

In my experience brass from rounds fired in a semi-auto will continue to stretch a little as the bolt comes out of full battery. Unless the fired brass will easily chamber in your rifle, the measurement of brass fired in the rifle may be a little long. You might want to consider adjusting your sizing die in .001" increments until the brass finally chambers easily, then add .002" to that as a starting point.

Once you get the set back that works best, write everything down in a log. Document the brass head stamp and how many times it was fired. You may have to make adjustments depending on brass head stamp. I have 2 full notebooks with information I have logged over the past 30 years and it saves me a lot of time when I am setting up to reload a particular caliber.

20

Everyone has their method for lubing cases. I put them in a plastic bag and squeeze in some RCBS glycerin lube. I then tumble the bag a few times and then let it set at least over night. The lube seems to migrate over the brass very well. If the cases seem a little dry squeeze in some more lube, tumble and let it set over night again. This means you have to think ahead a few days but it has worked for me for several years. The case are not too wet and it saves on lube over using the pad. kwg