Mandrel vs Button vs bushing

[Wildstreak]

When I started handloading I probably like most, I used a 2 die set that included a full length sizing die with an expander ball and a seating die. When I learned about neck bushing dies I made the switch pretty quickly, they made sense to me. Now I am seeing a trend move to expander mandrels. As far as I can tell a mandrel and button do the same thing with the exception that a mandrel gives you size options to customize how much you want to open the neck. But what I don't understand and maybe I am just an idiot (which is often the case) is I have seen/heard/read folks using both the mandrel and a bushing.

Can someone please explain this school of thought to me? Other than possibly fixing the neck from dropping the brass or whatever, I just don't understand using both.

 

[Lawnboi]

Most off the shelf dies, that use a button, squeeze the living shit out of the neck, doing much much more work than needed, then they drag a caliber size expander through them, most times when the case is unsupported.

Bushings just allow you to adjust that squeeze. Mandrels are supposed to uniform the hole the bullets going in while not messing with the shoulder, unlike the button

I think it’s generally accepted in the practical shooting community that something needs to be used to uniform the hole the bullet is going in. Lots can happen to a neck. Dents, stuff you can’t really tell by eye, differing neck thickness.

Bushing dies also can create another problem, they don’t size down to the shoulder so you can end up with excess brass there.

 

[rayporter]

Lawnboi has pretty much hit the high lights.

in general benchresters use full length bushing dies and turn necks to get an even tension.
annealing helps some and more and more are annealing. the mandrel is not used by many as i have not heard of any one using one. some long range shooters do use a mandrel but at this point i think they are few.

you are correct in that they do the same thing in different ways. uneven unturned necks may have uneven tension and they will have a different fit in the chamber that may cause an offset of the bullet alignment. in this case a mandrel may cause a problem that a bushing and a turned neck wont have. the mandrels used to do this are used last to open the neck and the mandrel is tapered for less drastic working of the brass.

 

[Lawnboi]

Lawnboi has pretty much hit the high lights.

in general benchresters use full length bushing dies and turn necks to get an even tension.
annealing helps some and more and more are annealing. the mandrel is not used by many as i have not heard of any one using one. some long range shooters do use a mandrel but at this point i think they are few.

you are correct in that they do the same thing in different ways. uneven unturned necks may have uneven tension and they will have a different fit in the chamber that may cause an offset of the bullet alignment. in this case a mandrel may cause a problem that a bushing and a turned neck wont have. the mandrels used to do this are used last to open the neck and the mandrel is tapered for less drastic working of the brass.

Lots of guys in the steel shooting world are setting neck tension instead of running a button.

Some new ideas on dies and bushings are out there too with the short action customs dies and even regular neck bushings now. Just the SAC bushing in my wilson full length sizer eliminated my doughnut problem

 

[Mike D Texas]

I use a full length bushing die and set final neck diameter with a mandrel. It doesn’t work the brass near as bad as an expander button.


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[jhm2023]

Last year I switched from full length size with the neck expander installed to full length size with the decapping/neck expander assembly removed then follow up with a 21st century neck mandrel. Depending on the bullet and cartridge I'm loading I'll use a mandrel that is .002 or .0015 under the bullet diameter. Since I've started doing this, all of the loads I've worked up have had single digit SD and at or under half moa accuracy. I can also feel the consistency in seating pressure after using a neck mandrel.

 

[Clarktar]

Last year I switched from full length size with the neck expander installed to full length size with the decapping/neck expander assembly removed then follow up with a 21st century neck mandrel. Depending on the bullet and cartridge I'm loading I'll use a mandrel that is .002 or .0015 under the bullet diameter. Since I've started doing this, all of the loads I've worked up have had single digit SD and at or under half moa accuracy. I can also feel the consistency in seating pressure after using a neck mandrel.

I'm going to look into this. So you are just using a full length body die (RCBS, Redding, etc) then you use a expander die body and mandrel from 21st to set your necks up. Then use a bullet seating die, correct?

21st looks like they have some nice products. I like the neck turning tool...

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[z987k]

Last year I switched from full length size with the neck expander installed to full length size with the decapping/neck expander assembly removed then follow up with a 21st century neck mandrel. Depending on the bullet and cartridge I'm loading I'll use a mandrel that is .002 or .0015 under the bullet diameter. Since I've started doing this, all of the loads I've worked up have had single digit SD and at or under half moa accuracy. I can also feel the consistency in seating pressure after using a neck mandrel.

This is what I'm doing now as well.

 

[jhm2023]

I'm going to look into this. So you are just using a full length body die (RCBS, Redding, etc) then you use a expander die body and mandrel from 21st to set your necks up. Then use a bullet seating die, correct?

21st looks like they have some nice products. I like the neck turning tool...

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That's exactly how I'm doing it. Use a regular full length size die but with the decapping rod completely removed. After that I use the 21st century expander die then clean the sizing wax off in a tumbler, prime ,charge and seat bullets like normal. I prefer Hornady dies due to the bullet alignment sleeve and the ability to add the microjust seating stem. I also like the window version of the mandrel die for ease of setup. For Hammer bullets I use a mandrel that is .0015 undersize and for others .002 under. Hammers are .0005 oversize is my reasoning for the difference.

 

[Jstanley79]

Everyone has all made great points. One area that has not been mentioned is that different brass manufactures all have different neck wall thicknesses. Lapua will differ from Hornady, Peterson will differ from ADG, Winchester will differ from Alpha, so on and so on. Having the ability to interchange bushings will allow you to control the amount of neck tension you desire.

My process on all of my comp and hunting rifles is as follows. Measure a loaded round and subtract .003-.004 and that is what my bushing size will be (I run SAC bushings). Run all my brass through a FL bushing sizing die. Then they all get run through a 21st Century mandrel. I almost all of the time use a mandrel that is .0025 under bullet diameter putting my neck tension right at .003. In all of my testing I've got the best results with .003 neck tension.

 

[Clarktar]

Thanks for the expanded process notes. Anyone turning necks?

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[Lawnboi]

Thanks for the expanded process notes. Anyone turning necks?

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No, and I would not shoot a cartridge if I had to do this.
The thought of turning every piece of brass makes me cringe

Another thing to keep in mind when doing this is annealing makes a difference in spring back. Just because you put a -.002 rod through the hole dosnt mean you have 2 thou neck tension. Lots of variable can change that number.

I do exactly as above. Or did, I have a SAC die now that I’m experimenting with the mandrel in. But size with just a decapping rod and bushing, and mandrel after in a separate step.

My goal is to streamline now though, but it needs to remain as consistent.

 

[Ammo29]

If using a FL sizing die with a mandrel, I remove the entire decapping rod from the die. I use a Mighty Armory Blue decapping die in station 1 on my 550c to deprime, then the shoulder is bumped and neck squeezed down with the FL sizing die (decapping rod removed) in Station 2 then the mandrel in station 3 for final neck tension.

 

[Harvey_NW]

Not saying the extra work won't give you a measurable difference in terms of specs, because it will, but in my opinion there is definitely a point of diminishing return. I know plenty of other reloaders that use a standard full length sizing die with expander button and have no problem working up consistent sub MOA loads. The juice isn't worth the squeeze for me.

 

[Harvey_NW]

Another thing to keep in mind when doing this is annealing makes a difference in spring back. Just because you put a -.002 rod through the hole dosnt mean you have 2 thou neck tension. Lots of variable can change that number.

Since you mentioned this in another post I took some initial measurements of new Peterson 25 Creedmoor brass after being ran over a .256 expander ball twice, using the blades of the caliper to take an ID neck measurement I was consistently getting .253/.2535.

That being said, I'm using graphite lube in the necks now and proceeded to not give a shit about neck tension and just see what happens with what I have. After an initial break in and seating depth test, I shot an OCW and got down to almost .25" 3 shot group, with an ES of 8. The velocity increase was pretty linear, the last group had the largest ES of 33fps, most other groups were sub 20fps.

Most would say any load development before a barrel is broken in, expander buttons, and .004" neck tension are a recipe for disaster. I think there's a lot of reloading voodoo out there.

 

[ResearchinStuff]

some of this stuff has to be used together to really work well, at least in terms of producing ammo with low runout/high concentricity.

generic dies and generic brass seem to work together pretty well, I normally hit sub moa with enough experimentation (there have been a couple exceptions). I honestly think the tolerances and errors allow for some cancellation and accidental good results.

Bushing dies, no mandrel, no expander: you better be neck turning, because unless every case has a perfectly consistent, concentric neck your bullets will be out of line with the center of the case.

don't want to neck turn, but still want to use a bushing die to minimize the working of your nect? better add in a mandrel or expander of some type, that way you can still produce ammo that has bullets pointing straight down the pipe. I haven't tried this out yet with cheap brass, but I suspect wildly inconsistent brass (R-P, etc) will still have high runout using this approach because the necks lack uniformity.

Neck turning is zero fun, and a huge time sink, I think that is why mandrels are increasing in popularity.

Annealing in theory will help everything be more consistent, but I haven't experimented with that yet.

 

[Lawnboi]

Since you mentioned this in another post I took some initial measurements of new Peterson 25 Creedmoor brass after being ran over a .256 expander ball twice, using the blades of the caliper to take an ID neck measurement I was consistently getting .253/.2535.

That being said, I'm using graphite lube in the necks now and proceeded to not give a shit about neck tension and just see what happens with what I have. After an initial break in and seating depth test, I shot an OCW and got down to almost .25" 3 shot group, with an ES of 8. The velocity increase was pretty linear, the last group had the largest ES of 33fps, most other groups were sub 20fps.

Most would say any load development before a barrel is broken in, expander buttons, and .004" neck tension are a recipe for disaster. I think there's a lot of reloading voodoo out there.

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I’d agree that there is a lot of crap out there about having perfect ammo that really dosnt pertain to most. I’m far on the side of thinking that most load development that’s done today by most guys is a waste of time. And I think 2-4 thou is acceptable if you can keep it repeatable through multiple loadings. That’s what I want out of my loads, is to be able to load a batch and have it do the same exact thing as the last batch, and I think there in lies the problem with overworking/ one size fits all approach. As you can see in your measurements that it seems the more you move the brass over what your goal is the more spring back occurs. Not always a problem but post annealing on some of my brass with factory dies leaves neck tension that causes a ring on the bullets from the stem.

It works, not arguing there. I’m going back to using a standard die for most of my 223 stuff because the rifle just won’t shoot the difference. But on my guns with good barrels on them, I want to be the weak link in the system and not the rifle.

 

[Lawnboi]

Annealing in theory will help everything be more consistent, but I haven't experimented with that yet.

The biggest benefit Iv seen for annealing is brass that remains fairly consistent throughout firings. Without I was having to mess with the die, mess with bushing size, to keep everything the same. Once I started annealing my die dosnt need adjusting, and the same bushing can be used. Brass is expensive, and I want all the usable life I can get. That and I hate wasting time and brass in the loading room.

 

[chasingbulls]

That's exactly how I'm doing it. Use a regular full length size die but with the decapping rod completely removed. After that I use the 21st century expander die then clean the sizing wax off in a tumbler, prime ,charge and seat bullets like normal. I prefer Hornady dies due to the bullet alignment sleeve and the ability to add the microjust seating stem. I also like the window version of the mandrel die for ease of setup. For Hammer bullets I use a mandrel that is .0015 undersize and for others .002 under. Hammers are .0005 oversize is my reasoning for the difference.

Im really interested in doing your way jhm2023...this is a stupid question as I am just now getting into reloading. When I run my brass through the FL die with decapping rod removed am I worried about resizing the neck to .002"?...Or is this achieved with the Mandrel only? Thank you for your help

 

[gpo1956]

The bushing emphasizes the outside of the neck. The mandrel emphasizes the inside of the neck.