Expander buttons, mandrels, and dies, oh my. Reloading help please.

M

mjperk

Guest
Long time reader, first time poster here. I hope this is the right forum for this topic...

First off, please bear with me as I have a TON of questions. I apologize if it gets lengthy but I am unable to definitively find answers to them all or how all the puzzle pieces fit together. I have searched the forum before, but have failed to find any definitive answers which is why I come to you now.

I have been loading for a while and have a basic understanding of the process, but recently upgraded equipment and am trying to develop more accurate loads to get started in bench rest competition for my bolt action .308. I picked up a competition neck sizing bushing die from Redding, the body die from Redding, and the ultra micrometer seating die from Forster. The bushing neck die is the variable that is throwing me off as I do not have any experience with this style of die.

I have always used a neck button, however that has gone away with the new dies. The more I read, the more I realize competition shooters don’t seem to use them at all.
1.) Is this simply because they might create a neck that is off-axis with relation to the rest of the case? Run out?

In my haste, I ordered the carbide button kit for the neck die, but am wondering if it is the best way to go moving forward. I see that a lot of people use a Sinclair 05-3000 expanding mandrel instead or a similar product from K&M. After a call to Redding, their tech told me that this step could also be accomplished by a neck turning pilot that forces dents out and resizes the ID as well.
2.) Is the intent of the expanding mandrels that they only be used to remove dented necks, or is the intent that you size every case, every time?
3.) Sort of along the same lines as question 2, is the intent with the bushing dies that you don't need to neck expand at all (unless there is a dent) and that after sizing the cases are ready for bullet seating?
4.) The Redding tech to me that using a neck turner to make the ID concentric correct also sizes the neck for seating. But doesn’t that defeat the purpose of selecting the correct bushing if you’re just going to change the ID, and thus the OD by expanding it on a neck turning pilot?
5.) The Forster site says that their neck turner pilot undersizes the neck ID to .0020 below the bullet diameter. So if you’re using this to control neck tension, it would seem to me that it defeats the point of using bushing dies, which is to control (and adjust) neck tension isn’t it?

In the past, I have used a neck turner to ensure uniform thickness. I have the Forster hand held outside turner. The bushing dies will make the OD of the case neck concentric--I understand that. If I am interpreting correctly, the idea is that you use the correct bushing to ensure neck OD is correct, thus the bullet will have the proper tension when seated.
6.) Is this why no expander ball is needed, because it is sizing the neck correctly in this step?

The second big part that I don't understand is that in the past I have resized the case before neck turning. If I’m not mistaken the resizing button basically forces the case ID to be concentric along some axis whether it is right or wrong. This is important because the neck turning pilot rides on this inside surface and shaves the OD so that it is also concentric in relation to the ID. Using the operation with an expander button, you should get a correct ID that is concentric, and an OD that is also concentric to the ID with consistent wall thickness all the way around.

With the new setup (bushing neck die) there is no expander ball in the middle and the neck die only forces the OD into concentricity. It then follows that because of varying wall thickness, the ID will likely have some run out present. This is an issue because it will create inconsistent clamping force on the bullet. So it stands to reason that this method would work best if the wall thickness was indeed consistent because this is the only way the concentric OD would drive a concentric ID as well. The problem with this is that the neck turning pilot (assumed to be perfectly concentric) is now riding on the ID which is not perfectly concentric due to varying wall thickness that exists in our non-perfect world. If the pilot is pushed into place, thus forcing the ID into concentricity, the OD that was just resized with the neck bushing dies will be forced out of concentricity (essentially undoing that operation completely). So this brings me to my next set of questions:
7.) Why neck turn on an OD that was concentric to begin with?
8.) Why even use bushing dies to force the OD into concentricity if it is to be undone by the neck turning operation?
9.) Wouldn’t you be better served by reaming the ID at that point?

The order of operations that I think it should be, but doesn’t necessarily make logical sense to me is:
a.) Full length body size (only if the shoulder needs to be pushed back)
b.) Neck expander mandrel (only if the neck is dented and won’t run through the size die correctly)
c.) Neck resize
d.) Neck turn
e.) OAL trim, chamfer, etc.

10.) Is this order correct, or where have I gone wrong?

Hopefully this all makes sense and you can help shed some light. I guess I don't truly understand the benefit an expanding mandrel vs a ball neck expander at this point, and how the neck turning fits in without undoing the neck sizing.

Thanks,
Max
 
The important item you left out is...what kind of Rifle do you have.?
If the Rifle has a standard SAAMI chamber, it probably has quite a bit of clearance in the neck already, so you really want to avoid turning any more off. The concept of neck turning is really reserved for Rifles that have chambers that are smaller in diameter in the neck so as to allow you to turn the necks to the proper wall thickness and clearance in that chamber.

What you need to do is simply load up your rounds with some cheap bullets and fire each case once. The bullet its self will remove the dent. This "fire forming" will get everything straight, remove all dents, and the case will be matched to your chamber.

Now you can trim everything to length and debut the case mouth. After that, simply put the proper bushing in your Redding Die, neck size and decamp the case, run your case through the body die to full length size it and push the shoulder back a couple of thousanths, prime the case, add the powder, and insert the bullet.

You want to use a neck bushing that gives the bullet about .002 to .003 interference fit in the neck to start with. You can experiment with different size bushings later to see what your Rifle likes.

You can save yourself a lot of grief by buying cases that are reasonably concentric in the neck wall thickness. Remington is probably the worst, Lapua and RWS the best. Buy yourself 100 Lapua 308 cases and you can shoot for a long time on those.

So, what type of Rifle are you shooting?
 
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Sounds to me like your where I was a few years back and about to step off in to the world of benchrest shooting.

Be careful going forward. Once you try a benchrest rifle and get the neck turning and stuff worked out all of your old rifles and guns will pretty much just collect dust.

It sounds like the rifle your working on now is the one that will push you over the edge. For me it was a 300 Weatherby that a gunsmith named Truman Wilson put a new barrel on and re-chambered. While he worked on it he explained to me some of the shortcomings of .300 Weatherby for accuracy. It was chambered for neck turning but just enough that a good Norma case would just shave just enough to barely clean up on one side and deep enough on the other to true up.

I think I was going from buttons to expanding mandrels by then to neck turn.

Here is a link to show you what I mean.

https://www.kmshooting.com/catalog/case-neck-expanding-tools/expand-iron_complete.html

What you want to do is get your expanding mandrel and the turning mandrel in your neck turning tool from the same place and preferably at the same time. There sizes have to match up. The expanding iron has to size up the neck so the turning pilot fits just right for the speed you are turning your necks at. A little to fast and everything heats up and gets tight. That's why many of us go with a carbide pilot. They can be polished to a finer finish a produce less heat.

https://www.kmshooting.com/catalog/with-carbide-cutting-pilot-and-tool-steel-cutter/micro-adjustable-neck-turner-complete-with-carbide-cutting-pilot-and-shell-holder.html

I remember back then I came across some really good books. I think this was the heavy duty one.

http://www.midwayusa.com/product/776339/the-benchrest-shooting-primer-book-edited-by-dave-brennan

Then again maybe is was a special edition of Shooting Times. There were a few.


P.S. Also I think what happens with the expander button on regular reloading is it occurs to you that the button is just plowing its way through the case neck stretching it way out and then the neck part of the die comes down squeezing it smaller and the on the back stroke here come that button again plowing back through. If you think about it hard it's a wonder we've been doing it.

Loading on my benchrest rifle most of the time I can just run the case partway into the neck sizing die and just the neck sizer bushing like in your Redding dies makes it just enough smaller to hold the bullet. Some time I do have to full length size or just push the shoulder of the case back if the fit in the chamber of a fired case says so. To check this I neck size and take out the primer. Then I take the firing pin out of my rifle. Then I see how the bolt feels when I close and open it.
 
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I shoulder bump gauge is much better

" than this method. " Then I take the firing pin out of my rifle. Then I see how the bolt feels when I close and open it."

I have seen it many times over the years of creating excessive headspace. If the case is fat toward the head, that is what you will be feeling, if you keep sizing till it "feels good" there is a chance you will have way more shoulder bump than you realize. Also a stiff ejector can give you a false reading.

I was at a match one time when a fellow was complaining how his bolt was stiff closing on a sized case. He said " I turned my sizing die tighter and it was better but could still feel the bolt close.

Well, I ran that case through a small base die without touching the shoulder. The case fell right in with no resistance at all. He was bumping the shoulder right at .020 to much. It was an eye opening experience for him.
You really need good hard numbers for shoulder bump in my opinion.

Richard Brensing
 
+1
Bottom line, if you don't have the feel that you want at what you have decided is your maximum shoulder bump (measured in comparison with a case that is at maximum dimension for that rifle/barrel combination) your die is too large for your chamber, and no amount of fiddling will solve the problem. You need a different die.

Over the years I have read experienced shooters extolling the virtues of using one's rifle as a gauge for setting a FL die. What these fellows don't seem to get is that if they have been doing this successfully for some time, that their dies are proper for their chambers, BUT the fellow's that they are advising may not be.

Some years back, a couple of friends had benchrest gunsmiths build them 6BR varmint rifles. Suspecting that those chambers might be tighter than standard, I advised them to send fired brass to Harrell's Precision so that they would have dies that were correct for their chambers. Not being up to date on the state of the art, they both opted for standard Redding type S FL dies, only to discover that to get the bolt close feel that they were looking for, that they had to set their dies to produce a shoulder bump of .0025. They now have Harrell's dies. My point is that when dealing with situations at a distance, we generally do not know the dimensions of people's chambers or dies, so the best option is to tell them to measure bump, and if that does not yield the desired feel, to get another die.
 
Good points Boyd Allen and Richard both.

I have a Harrell's die and a sort of a head space gage the gunsmith made when he sent a barrel. I don't remember for sure if he said he did anything to the die but for the gage he made it out of the stub of barrel blank with the reamer he used on the barrel and it seems to work marvels for watching head space grow. I can pretty much measure a fired case with it and no if it is a tight case check in the rifle.

Richard,

I have seen it many times over the years of creating excessive head space. If the case is fat toward the head, that is what you will be feeling, if you keep sizing till it "feels good" there is a chance you will have way more shoulder bump than you realize. Also a stiff ejector can give you a false reading.
Click to expand...

I have at times have had to bump back my bump die an extra amount more than it seemed I should have had too. Maybe on one of the other barrels. I'll watch for it and give it more consideration.
 
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