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Galling Wilson expanding mandrel

amork

Well-Known Member
Joined
Nov 10, 2014
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182
Location
montana
so recently I started using an expanding mandrel on new cases to uniform necks prior to the first firing. I've done it on once fired brass before but I guess I hadn't actually did it on new cases till last night. I had 200 new lapua .260 cases I was going to run through the mandrel but had to stop because I was struggling with what I thought was having to use to much force to size them. I had used imperial dry neck lube on them but it seemed like the graphite wouldn't stick to the inside of the new cases. I probably ran 10 of them through the mandrel before I stopped. Has anyone ran into this? I watched videos of people following the same process and didn't seem to have issues. I don't want to mess this brass up so figured I'd ask around before proceeding.
 
Dry graphite is not a good lube on clean brass for sliding operations like running a mandrel through the neck. Wax or lanolin based lube will run better. You can use alcohol, acetone, or untreated corncob/walnut to remove the lube after sizing.


AMP posted this in one of their FAQs:
Screenshot 2022-07-08 130951.png
 
on new cases try deburring first and sizing wax of choice, if still too much resistance try annealing but only as last resort most quality new brass is already annealed and polished to remove discoloration.
 
Thanks guys! I'll give some imperial sizing wax a go. I was hoping for dry lube to work but it is what it is.
 
Dry graphite is not a good lube on clean brass for sliding operations like running a mandrel through the neck. Wax or lanolin based lube will run better. You can use alcohol, acetone, or untreated corncob/walnut to remove the lube after sizing.


AMP posted this in one of their FAQs:
View attachment 377513
I have found that using bushing dies, and by using the correct bushing to set tension I don't need a mandrel. I have a few less steps in reloading that way so far. I agree in the annealing each time. I do watch for spring-back also. If I start out with new case if possible and set case length, cut neck for thickness. If I am fireforming the case I am not so worried about neck tension at that time. After that it's a different story. The other is I am just getting into using bushing dies, and so far I like them very much. Presently working on adding FL bushing dies to my reloading equipment.
P.S. Still learning @ 74.
 
Just because you can set the desired sizing without expansion doesn't mean you should.
Expansion (or what I call bullet pre-seating) is important to reduce loaded runout, and to ensure long term tension for stored ammo.
 
Just because you can set the desired sizing without expansion doesn't mean you should.
Expansion (or what I call bullet pre-seating) is important to reduce loaded runout, and to ensure long term tension for stored ammo.
correct me if I'm wrong but your saying using a mandrel or something similar to set your neck tension to something less than what an expander ball wound can cause more runout?
 
There are other options to try besides what you have tried so far, one is Dupont Non -Stick Dry film Lubricant, I got from Amazon and another is Boron nitride, a dry powder, both applied to bird shot bb's. I'm not saying that these dry lubes are the answer but are only other options that you could try. I have used both for lubricating neck and bullet when seating, and works well.
 
correct me if I'm wrong but your saying using a mandrel or something similar to set your neck tension to something less than what an expander ball wound can cause more runout?
It isn't about setting a particular interference, as that can just be set with a bushing. And it isn't because I like adding steps to reloading :)

I was THE guy who began mandrel pre-seating ~20yrs ago, and it spread onward to the crazy today.
What I was doing is fixing the problem that was pulling necks off center, contributing to RUNOUT.
I could just remove buttons, or turn them down a bit, adjust bushings, but I noticed that I could still have significant runout with that. I also noticed over time that bullet grip (neck tension) was decreasing. That if I neck sized down, with no followup expansion, necks would continue springing back outward over time. The load results would change with that. So enough expansion was needed to cause yielding(sizing), to bias spring back inward instead of outward. But that's all, just that little bit.

The runout with down sizing only of necks was due to pushing thickness variance into interference with seating bullets. I took care of this anyway with neck turning, and part of turning is mandrel expansion for fitting to a turning mandrel, and I noticed the quality of that expansion method was very good (better than button type). I could push thickness variance outward without affecting neck center.
The K&M Expandiron was fine for neck turning but too big for reloading/bullet preseating. Sinclair's mandrels were the right size, so that's what I went with. I brought this to all shooting forums of the day. Today there are all kinds of mandrel choices (that's good),, but for the wrong reason..
We don't need mandrels to set TENSION. They're not needed for that, and bushing folks know they can set tension without mandrels.
It's my contention that mandrels and expansion in general were never about that, but they're still needed.
There is an important matter and other great potentials with mandrel use, but that should be another thread.
 
Just because you can set the desired sizing without expansion doesn't mean you should.
Expansion (or what I call bullet pre-seating) is important to reduce loaded runout, and to ensure long term tension for stored ammo.
With long term storage of hand loads, I don't have any presently. Because I have just started using bushing dies. I have ammo that has been stored for years. Loaded use RCBS either neck sizing dies. or FL dies. I hadn't until last year used a concentric tool to check my reloads. To my surprise almost all the reload I check were almost 0 runout. In those pass years I did cut neck for variance in neck thickness, and started over 20yr ago, and upgraded my equipment this pass year to 21st Cty neck cutting system. To the point of have additional cutting set ups. so I don't have to change my final cut for thickness for that caliber.
I size down to what is needed to achieve 2ths tension in my necks. In reading now, what you are saying that the spring back continue even after that. Interesting! I guess one way to test that is to set up and do my case work and set the ID for that cartridge including the tension. Set the case aside and check back in a couple of months,(unloaded) and more to see what's going on.
I have in the pass placed your input into my notes that are about 35 pages long now. I see I got some additional note to be place now. I also note where the input come from. I work towards reducing inconsistences in my reloads. I had bow hunted for about 15 year, and didn't do much rifle hunting until just as of late. The amount of info out there is almost to much. :)
In rereading you blog, and getting it typed, I kind of missed the boat by some.
Fools rush in, where wise men do go. I am in the first part.
 
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I have found that using bushing dies, and by using the correct bushing to set tension I don't need a mandrel.
This thread was about the LE Wilson "new brass" mandrel, which is designed to iron out neck dings in bulk packaged virgin brass and leave a sufficient fit in the neck to hold a bullet.


Before companies sold incremental mandrels like they do now, there were limited options of neck turning expanding mandrels, and then neck turning arbors that were often mistakenly called "turning mandrels" because they were slightly smaller than the expander. People used arbors as expander mandrels paired with bushing dies, but ultimately neither the expanding mandrel or turning arbor was the correct fit in new brass to maintain good interference fit for loading new cases without resizing them first.

It's a niche tool for new brass, not really relevant to the post-firing sizing processes.
 

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