At what step to chamfer

[Viperdoc]

I have a Giraud trimmer that trims necks to length, and puts a chamfer inside and out- it is a great tool, well made and well designed. I have been trying two methods for reloading- first is to run an oversize mandrel through the neck, and then the S type die without the expander ball. The other method has been to use the simpler method of running the case with the ball in place- not sure the mandrel method is much better unless turning all cases.

Anyway, with the mandrel, the case necks are a lot larger than with the use of the expander ball. So, running these through the chamfer cutter should be putting more of a bevel on the outside versus the inside. Likewise, outside turning is going to take a lot more off of the neck compared to a case that is resized with a neck die and expander ball (without making some significant adjustments in the neck turner).

Is either of these techniques "better", or does it not matter?

 

[mikecr]

I don't know if this is a wildcat, sized up, or down. But for new brass at a neck ID size ready to load, I turn first.
The turner cutter should be set to the depth that produces correct thickness, regardless of cal or cartridge.
For ease of quality turning, your necks should be expanded to match the turning mandrel. But how you manage this depends on what you're doing, and on the springback and thickness of the necks. You do what you gotta do there..
The trimmer depth setting should also be adjustable for what you want, regardless of cal or cartridge. Just as you would trimming/chamfering by hand.

With either operation, adjustments are in order.

 

[Viperdoc]

Probably tried to ask too much. So, if planning on neck turning, is it better to expand the neck with an oversized mandrel to get it to fit onto the neck turner. Won't this end up working the brass a lot. Seems like my finished rounds are around 0.292, with the standard expander ball and 0.286 neck die: 0.289 (gives a 0.003 neck tension), but with the mandrel, they end up at 0.295.

For max accuracy, should the order then be:

1. decap
2. resize (FL with type S Redding die, no expander ball)
3. mandrel
4. turn
5. resize again
etc?

Seems like this would end up working the neck up and down a lot.

 

[Ackman]

It's not as complicated as you're making it. With new brass, necksize using a die with an expander ball, then give it a good inside chamfer. That's it. You won't have to chamfer again. Reloading, use any dies you wish. Bushing dies work the brass less. Case trimming.....don't even worry about it. Chambers are much longer than brass. Unless your chamber was cut with a reamer custom sized to that brass, it's so much longer that trimming isn't necessary and probably never will be. Neckturning......you'll just have to experiment to find the right combination of tools to get the right neck tension. I've never had any problem. Even if it's a little tight going on the mandrel, Lee lube works really well.

 

[Kenny474]

If the mandrel you are using is sizing the neck further than what is necessary, than stop using it. And as far as "max accuracy" is concerned, that is a matter you need to figure out by shooting your gun, not being theoretical at the loading bench.

Also, why are you turning necks on fired brass? If you have a chamber that necessitates turned brass than it should be done before it ever sees the rifle. What caliber is this rifle you are using?

I think you have overcomplicated the whole process and need to simplify your procedure.

Bottom line, use the proper mandrel on your neck turner so it fits without being oversize. That way it goes on as used, not sized to fit the turning tool.

I turn my brass straight from the sizing die, no extra steps, just turn it to the desired thickness.

Sizing up and down a million times will do nothing but hurt concentricity.

 

[mikecr]

Seems like my finished rounds are around 0.292, with the standard expander ball and 0.286 neck die: 0.289 (gives a 0.003 neck tension), but with the mandrel, they end up at 0.295.

I take it this is 26cal
.264+.028(.014thick) = .292

For this you should simply use a .289 bushing, and no button expander.
This provides 1.5thou tension(plenty) after 1.5thou springback. [0.289-(0.264+0.028)+0.0015 = -.0015]
For turning you need to use the CORRECT expander mandrel -that matches your turning mandrel.
Measure them both and all should makes sense.

I can suggest that your current expander mandrel, leaving the ODs at .295, is INCORRECT(or very poor at the least). [0.295-(0.264+0.028) = .003] over cal!!
The last time I ran into this kind of miserable sizing mismatch for turning, it was with K&Ms turning system. To correct it, I went to Sinclair, and never had an issue like this again. Sinclair's turning/expander mandrels are the correct size for reloading.

Anyway, you are way oversizing -both directions, currently..