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FL or bushing die?

Well you need a sizer die to start the process. But remember if you use a standard SAAMI one step sizer you run a risk of causing runout numbers to go up. Which will effect accuracy.

Frankly if you want to use an expander mandrel I don't see a way around using a bushing die to allow you to control neck sizing as precisely as possible before applying the mandrel. From what I can glean the mandrel step is suppose to give better case to case accuracy on tension. On these steps anything you can do to improve the result will pay off in consistency.
So you'd recommend using a FL bushing die before running the mandrel through?
 
So you'd recommend using a FL bushing die before running the mandrel through?
It would to give your sizing more control. Like I said earlier I have never used a mandrel step, but it seems like a positive approach. If you use a basic FL die you have zero control over how much it changes the neck diameter. A FL bushing die will give you the most control.

Something else, buy an annealer. You will thank me later.
 
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If you are going to use bushing dies: I would set up to cut all my neck to a thickness. So matter what case you are using the O.D. will be the same. Necks are not perfectly round to start with. Some case are better than others. So now you are starting to go down the rabbit hole. I just started to use bushing dies. Had some problems in getting the bushing set up to size the full length of the neck. Got that cover now. I stepping down a 280AI case to 6mm or .243. I ended up making 4 steps to achieve the O.D. of the case. I determine that having to step down several times, it wasn't worth it to change out the busing each time. I have 2, 280AI bushing dies and got 2 more coming. I have a turret press, so I can leave the dies in place to do the reduction. I have a tight chamber so all the brass have to be cut or thinned. So I started out with case that the O.D. was about 0.314 or there about. I cut the necks to .013 thickness of .026 for a total of 0.31. I screwed up a couple of case to my this like. It was a pain in the butt to change out the bushing. So I am ending that by getting additional bushing dies. So I would highly recommend cutting your neck to a thickness, and not under .013. The other is be careful if you stepping down the neck to a different caliber. The de-primer rod are sized to that caliber. So be careful on the down sizing of a case. I ran into that problem. Lucky I had a 25-06 bushing die and switch the rod out. Redding put me onto a company that had there rods. (can't order direct) So I order out additional de-capping rods. There more to it also. Cut all your case to length first, that way your thinning the neck setup will stop at the same place. Keep reading there more to it than meet the eye. Got love it too.
 
Bushing dies are super: The mot important is the BRASS- as mentioned in the above Have to stay with the same make. Lapua,Peterson, Alpha, Nosler, Winchester,Rem or ?? need to be the same make and batch. When I get brass I'll go for 3-500 at a time. Then one needs to inspect each-weight each,check neck thickness ETC ETC ETC because all is not created equal. Jumping to different brands means you'll need different size bushings ( they are not cheep any longer ) Then decide on tension stay .002-.003 Try to make each round the same, take your time that goes from doing the primer pockets to Deburring. Uniformity is the name of the game. If one starts off with bad brass all the work is not going to change it ( that includes cutting the necks or reaming the inside ) Its one thing to just take the high spots down... REMEMBER : UNIFORMITY & CONSISTENCY is the answer.
 
My suggestion….A Lee Collet Die and and a Redding Body Die. This process works the brass less than any other process. This process also allows me not to anneal the brass. Give it a try!
you can make your own mandrel and open up the tapered sleeve hole a bit where the mandrel passes though..to decrease neck tension.
 
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It would to give your sizing more control. Like I said earlier I have never used a mandrel step, but it seems like a positive approach. If you use a basic FL die you have zero control over how much it changes the neck diameter. A FL bushing die will give you the most control.

Something else, buy an annealer. You will thank me later.
wouldn't a mandrel correct FL/neck sizing ? I never heard using a FL bushing die and a mandrel.
 
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My suggestion….A Lee Collet Die and and a Redding Body Die. This process works the brass less than any other process. This process also allows me not to anneal the brass. Give it a try!
Is the body die and collet die the best to have minimal runout ?
 
A ton of good and varying advice..I will put in my vote for f/l die only! As stated above the problem with Bushing die is clearly varying neck thickness in brass...all brass even with the same manufacturer. I'm old school, tried Bushing die once to say I did, hoping for better results then what I was used too..
It wasn't dramatic or even noticeable enough to me...again Old... but I did struggle with different bullet weights and brass....I'm not a single load fella. I have dedicated go to loads but like to be able to try new things without wondering each time if I will crush shoulders, or worry about to much changing neck tension...IMHO..JUST ME!
 
wouldn't a mandrel correct FL/neck sizing ? I never heard using a bushing die and a mandrel.
On the back end yes, you can get to the same point of a certain inner case neck dimension using an FL and a mandrel.

But in terms of control over how far the brass moves you're at the mercy of the FL die dimension, and you have to either get it honed or go to a bushing to control how far down you're sizing. Final size is just as important as how far you move the brass to get to that point, and how far down it has to go to spring back to where you want it.

Bushing + mandrel is a common combination because you can 1) control the amount of sizing down with the bushing, 2) straighten any runout induced with the mandrel that 3) pushes neck thickenss variance outwards to 4) get to the ID you specified while 5) being able to quantify springback if you so desire.

You can get all of the above with other combinations of tools and steps, bushings and mandrels offer a lot of flexibility for experimenting because they come in so many sizes and are cheaper than dedicated honed FL dies and work in multiple chamberings inside a given caliber. It also might not make any difference depending on a bunch of other things like do you anneal, what are you chamber dimensions, quality of other loading processes, etc.
 
#1 how far the brass moves... meaning nothing can correct the runout as much as FL/bushing and mandreling verses standard FL/mandreling ? And how much more does a Redding standard FL die move brass vs say a RCBS FL ?

#2 would holding press lever for a few seconds control that spring back to not allow the brass to move as much?
 
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#1 Runout isn't an issue that's corrected by a sizing die, more on that later. I mean brass moving in terms of FL+mandrel might move the brass -.005 then +0.004 to get to a net -.001. A bushing and mandrel you could do -.0015 and +.0005 to get to the same -.001 point. The total distance the brass moves does have an impact on the case by work hardening the neck. Which leads to the the second point of:

#2 I'm meaning spring back here to describe how case hardness increases when being worked, and over time the case will spring back more no matter how long you hold it in the die or how tight the die is. Hardening can be accelerated by moving brass more than necessary, holding down longer won't change the dimensions of the fired case versus the inside of the die. An FL die can't be adjusted smaller as brass hardens and springs back more, resulting in less neck tension/interference fit/hoop tension (or whatever the popular semantic term is today) when you seat the bullet.


More ADHD thoughts, the "you" here is the indefinite, generic muse that my brain talks to itself with:

Runout can be managed in a lot of ways. If you're having runout problems then you should take a holistic look at your complete reloading process, including components. FL+button, FL+mandrel, bushing+button, bushing+mandrel, LCD, separate bump and neck dies, all of these should be able to produce low run out loaded rounds. All the combinations should work because there's a point where the die stops mattering in that it doesn't induce runout, but it won't correct for runout being induced elsewhere. Bullet seating is an important part of the process - the straightest brass around can be pushed out of true by a low quality seating die, and also by the combination of sizing and bullet fit. My experience tells me that shoving a flat base bullet into a very tightly sized, very hard neck with a generic seating will induce more run out than sliding a boat tail into a minimally sized, annealed neck using a chamber seating die. So which parts of the statement matters most? Bullet base, seating die, seating stem, neck die, neck size, neck hardness? I don't know, because there's no one right answer, just finding the right balance and process that works for you and your rifle. Controlling what I can to reduce the height of multiple tolerances in the stack is IMO more important than making any single tolerance nil at the expense of making another taller.

There's also a flip side issue to #2 up there that even as necks harden a standard minimum spec FL die might still be undersizing the neck, and the bullet seating operation will do double duty of seating and the final expansion of the neck, which can lead to inconsistencies in seating depth and more runout. A bushing die you can put in a smaller bushing and end up with more consistent final neck ID as the case hardens over its life cycle - if you don't anneal.

If you do anneal, you can get consistent results in other ways, including an FL die. That was the point about you can get there in a lot of ways, dies aren't the only part of the equation. If you FL size and anneal, there's a very real chance you never split a case neck before you lose the primer pocket. If an FL die is giving you the accuracy and precision you want, there wouldn't be a benefit to changing to a bushing/mandrel set up - cost/benefit return would be nothing because you get no benefit since you got no change. Now if you're looking for more precision than you're getting currently, the tuning options of a bushing/mandrel might be worth the cost because it's a way to see the impact of neck tension/et al adjustments on a target. But if you're not to where you'd see results of the change in ammo quality because you're doing one of many other things - using recycled brass, cheap bullets, a crappy chamber, a poorly stocked rifle, back to no benefit. You'll never see the results of changing your sizing process on paper unless it's the limiting factor of your loading AND shooting currently. Which takes me full circle back to runout. If runout is causing issues on the target for you, the sizing die isn't where to start IMO. A blank drawing board is, otherwise you might be shotgunning money at the problem trying new sizing dies instead of actually finding your true root problem elsewhere.
 
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