NOE .312 expander plug problem? loaded rounds wont case guage when finished?

[kevin]

Hey guys! I'm not sure how to handle this one I just started using a .312 ex-pander plug from NOE in a lee universal ex-pander die to make room made for a .311 sized boolet. I was previously using the Lyman M die dimensions of witch are .307-.308. Cases are lake city 7.62X51 sized using a plus .004 shell holder. Anyhow now with the extra flare in the case neck the finished rounds wont case gauge anymore. I should also mention that after seating the boolet I use a lee factory crimp die.

My first thought is to try a dry case neck lubricant witch i'm not too excited about just another step/cost ect. Before when using the M die I did not use any kind of a inside case neck lubricant and everything seem to work out fine. Perhaps the most important/relevant piece of information is that these round are feeding the mighty M1A and so there is risk of slam fire if rounds do not chamber cleanly henceforth why i case gauge them. i realize that is a step that is not necessary for most.

Maby I'm all mixed up on this, and most guys are using some kind of inside case neck lubricant when aggressively neck flaring with oversized expanders like this?

thanks everybody in advance! Man i just really like to shoot!

[BK7saum]

What does the neck of a fired case measure? How does that compare to the diameter of the case neck of your loaded round? The fired case neck should be approximately 0.001" less than your chamber allowing for brass springback.

A slug of the chamber or a cast would tell you for sure what your neck diameter goal should be.

I would image that the narrow 0.309" expander was allowing the case neck to size down your boolit when seating. Now that you have the appropriate sized expander, you boolits are not being sized down by the brass.

As long as the loaded case neck is less than your fired case neck, you should be okay. Most people allow for 0.003" less than the chamber neck.

Brad

[ulav8r]

A .311 diameter bullet should require a .310 diameter expander plug. At best, I would expect the brass to possibly contract to .311 after using the .312 expander if the brass is quickly retracted. If the sizer is held in the case for several seconds, then the sized brass will be closer to .312 and the bullet would be too loose to reliably stay in place.

[popper]

NOE has 312x308,316x312 expanders. First is flare size, 2nd is expander size. Either way set the die so it just flares ~ 0.010" - else the FCD won't remove all. 308W brass is thick necked so if really need 311 boolits you may have to neck turn. My guess you got the wrong expander. No idea what this is plus .004 shell holder.

[kevin]

+.004 thousands shell holder is one shell holder from a set of competition shellholders made by Redding that allows you to easily size to fit specific chambers. so as to do the minimal amount of sizing needed to improve case life and gain some accuracy although its more about case life improvement IMHO.

[kevin]

On NOE's web site they state that expander plug size should be .001 over sized boolet diameter. Hence using the .312 expander for .311 sized boolet this is correct

[fred2892]

Ok, start at the beginning.
Are you just starting to use cast bullets in this rifle?
Will your fired UNSIZED empty cases accept a .311 sized cast bullet?

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[ulav8r]

Did a quick check of NOE's website. The only .312 expander they show is a .312x.308, meaning only the first few thousandths of the neck are expanded to larger than bullet diameter. For a .311 bullet you should use a .312x.309-.310 expander for hunting rounds or a .312x.310-.3105 for target rounds.

Before going any further, however, you need to answer fred2892's question.

I did not find where they make recommendations on how to select expanders.

EDIT:
I mis-stated on sizes. What I actually meant was that the sized dimensions should be as stated. As mentioned in in later posts, the brass size after sizing will be different than the actual plug size.

[fatelvis]

NOE's measurements are to create .003" neck tension on the boolit when used correctly. Using the .312" expander for your .311" sized boolit is correct. The opening to the neck will be .001" oversized, to accept a hand-seated boolit, that will be started straight and true. The .308" portion of the expander will open up the remainder of the neck and give the .003" neck tension that NOE was targeting. I tend to use an alloy similar to Lyman #2, and my boolits seem to be hard enough to withstand the .003" tension without deforming/sizing down. BTW, I use Redding's dry neck lube dip when using these expanders, and it smooths up the process. They work well for me.

[kevin]

Hey Fred, aside from about 100 full length gas checked boolets for barrel break in I've just turned over the first 1000 cast rounds in the rifle. until this point all the cases were flared/expanded with the stock lyman M die mandrel witch mic's at about 308. yes the fired un-sized cases will accept a .311 diameter boolet.

[kevin]

Here is the little description copy and paste from NOE's site,

".316 x .312 Exp. Plug To use with Lee Universal Neck Expanding Die Turns it in to a true neck expander like a Lyman M-die. Use a expander that is .001" over your bullet size for best fit."

Hey Fatelvis, where did you see there target .003 neck tension. When I read this De-script i think that they are saying that the expander section of the plug or lower section should be .001 over the final sized boolet. this is the size expander plug i am using.

[kevin]

Also, i just bit the boolet so to speak and have started using the imperial dry neck lube in application media and it actually seems to have solved the problem. Cases now gauge well, seems amazing that just a little lube inside the neck could do that. Interesting post's though we seem to have some very different ideas about how much to expand case necks

[kevin]

I often wonder how much the gas check will "expand" a case neck upon boolet seating? Say a .311 gas check forced into a case neck only expanded to .308?

[fred2892]

The NOE sites advice for the plug size makes no sense to me at all.
Obviously the neck has to be smaller than the bullet or it will just drop through into the case.

For 30 cal cast bullets I aim for .002" under bullet size. So a neck that has been sized down to .306" needing to accept a .311" bullet will get a .309" expander with a .312" flare.

Except it WONT. Due to brass springback your .309" expander will most likely leave you closer to .308". So to get your ideal tension you actually need to expand to .310" which when the brass springs back will give you .309".

The .001" springback obviously varies with the brass thickness of your necks, the calibre you are using and the condition of your brass.
I make my own expander plugs and powder through expanders on my lathe so can easily fine tune dimensions to create the ideal.

I suspect your problem lies with setting the expander too deep. The upper flare should create a seat for the gas check only. Any deeper flare and the lee factory crimp will not be able to fully close the flare. The actual closing portion of the lee die is only about 1/16", if your flare is deeper than this it wont get closed and will leave you with a bulge which will obviously give you gauge problems. Try setting the expander to the shallowest depth so that it will only just hold your cast bullet upright. When looking from the side you should still be able to see part of the gas gas check above the flare.

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[fatelvis]

Hey Fatelvis, where did you see there target .003 neck tension. When I read this De-script i think that they are saying that the expander section of the plug or lower section should be .001 over the final sized boolet. this is the size expander plug i am using.

I called NOE and spoke to Al, and he explained just what I parroted to you. I'm happy to hear it's working for you now. Good shootin!


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[kevin]

Thanks every body for your input. much appreciated

[gloob]

I called NOE and spoke to Al, and he explained just what I parroted to you.

I'm not surprised.

But OTOH, I do not agree.

I preferentially use expander same size as the bullet.

Obviously the neck has to be smaller than the bullet or it will just drop through into the case.

This is true. But the expander doesn't have to be smaller than the bullet in order for this to be the case. People who neck size for target shooting have come to concensus that 2 mils undersize is about right.... But this is from sizing the neck DOWN in diameter. In fact, to get the neck 2 mils under from the sizing operation, you need to use bushing or mandrel that pushes neck to about 4 mils undersize; then it opens back up about 2 mils when it pops out of the die. If you size the neck too small, then you expand it back OUT to size, the case shrinks back after the expander is removed. By about 2 mils.

If you use an expander 1 mil larger than the bullet, you will end up with case about 1 mil smaller than the bullet, plus or minus depending on the elasticity of the brass, and all. But compared to the 2 mils under that you get from NECK SIZING, it is really about the same, due to "metal creep" or internal stresses in the brass left after necking down (neck wants to open up a little more after sizing it down, after the internal stresses are relieved). You get plenty of good neck tension by using an expander plug 1 mil larger than the bullet. I do it.* OP has done it. No problem. As long as the neck was originally sized at least a few mils too small to begin with, you get good neck tension.

If lubricant made the difference, OP might have had some minor amount of shoulder collapse when expanding without the lube.

*In pistol, I use expander same diameter as my cast bullets. But I use the same expander when loading jacketed bullets that are 1 mil smaller than the expander plug. Neck tension is more than adequate. In rifle, the hardness of my alloy and the gas checks mean I don't NEED to go out of my way to get custom expander so large. But I would have no qualms doing so. In fact, if I cared about a higher level of accuracy (which I'm the limiting factor, anyway!), I would also seek/make custom expanders for my rifle rounds, as well. And the expander plug would be at least as big as the bullet. I am not relying on manufacturer specs; I am measuring plug and bullets myself. This is the reality. For 9mm, for instance, I use NOE 38 special plug which measures true 356 thrughout, with a 360 flare. For 40 cal, I custom made a 401/404 expander using an expander for some rifle caliber that Lyman was kind enough to send me when my Glock didn't think too kindly of the ammo created by their stock 40 cal M expander.

OP, beware. IME with cast bullets in a rough loading autoloading rifle, the neck tension doesn't matter. You can't necessarily get enough neck tension to positively prevent setback. You may need to roll crimp into a crimp groove. The shorter flatter nose on a cast bullet can make the feeding process much different and potentially more violent.

I often wonder how much the gas check will "expand" a case neck upon boolet seating? Say a .311 gas check forced into a case neck only expanded to .308?

I have tried a variation of this. What I did was put the gas check on but not size it. Then seat it into the case. The gas check was hard enough to remain larger than the bullet. The bullet would easily pull out, if I unchambered a round, lol. Ejecting a case with the gas check still in the neck, bullet in the rifle. So I imagine gas checks (Lyman) are fairly hard. They shot fine, though.

[kevin]

Bulls eye Gloob, just the post I was hopping for, and don't worry I am very aware of the risk of bullet set back and the need for substantial crimp with the rough loading M1A, I defiantly put a stout one on these rounds with the dedicated lee factory crimp die witch makes its own crimp groove.

[ulav8r]

Did a quick check of NOE's website. The only .312 expander they show is a .312x.308, meaning only the first few thousandths of the neck are expanded to larger than bullet diameter. For a .311 bullet you should use a .312x.309-.310 expander for hunting rounds or a .312x.310-.3105 for target rounds.

Before going any further, however, you need to answer fred2892's question.

I did not find where they make recommendations on how to select expanders.

EDIT:
I mis-stated on sizes. What I actually meant was that the sized dimensions should be as stated. As mentioned in in later posts, the brass size after sizing will be different than the actual plug size.

My goal in sizing would be case neck to be .0005-.001 smaller than actual bullet size for target loads and brass .001-002 smaller than the bullet diameter for hunting loads. These would be starting points, subject to testing and improvement.

[gloob]

My goal in sizing would be case neck to be .0005-.001 smaller than actual bullet size for target loads and brass .001-002 smaller than the bullet diameter for hunting loads. These would be starting points, subject to testing and improvement.

So for a 311 bullet, can you clarify what size expander plug you would recommend? For me, I'm reading that as 311 expander for hunting loads and 312 expander for target loads, with a 313.5 to 314 flare. There seems to be a lot of confusion over expander sizes, (which the industry seems to participate in). The difficulty of accurately measuring the ID of a casemouth is part of the problem.