Oversized expander ball in FL sizing die? Anybody use one?

[SanPatHogger]

So in the search for loading better ammo I thought about maybe getting an expander ball that is slightly oversized to decrease neck tensiona little.
Anybody use one?
Right now I FL resize with a Lee die.
Getting more into prepping my brass a little better and was thinking this might be a cheap way to sneak out a little more accuracy/consistancy.

Custom Oversized Ez X Expander - Lee Precision

Custom Oversized Ez X Expander, for the Full Length Sizing die. Please specify how many thousandths you would like it oversized in the box below. Current lead time is around 4 weeks.

leeprecision.com

 

[CK1.0]

If you're heading down this path you should probably just go straight to using a mandrel die in a second step after you FL size (just ditch the expander stuff that's in the FL die now, and either replace the expander with a regular Lee decapping pin, or just decap separately with a universal decapper die before you start anything).

Like this: https://www.brownells.com/reloading...pander-die-body-sku749011715-38807-74483.aspx

and a mandrel: https://www.brownells.com/reloading...ander-mandrel-sku749019003-130716-240043.aspx

...seems most of us favor going -.002" under bullet diameter (which is actually considered a "turning mandrel"), but you can go -.001" under or split hairs even more if you want these days by using the LE Wilson mandrel stuff which come in half thou increments...

Chances are that it's not so much the OD of the expander ball or necessarily neck tension that's messing with you, so much as how you're doing it: pulling an expander of any kind up through a freshly sized neck kind of sucks, it screws the shoulder up a little too.

It sucks to add steps, but in the interests of accuracy and making better ammo, the mandrel is the way.

 

[acudaowner]

always wondered why no fl resizing dies made seem to use the expanding mandrels unless I just keep missing them , instead of bushings you would get the neck tension you want all while resizing your case instead of two steps you would only need one step resize and done .

 

[CK1.0]

always wondered why no fl resizing dies made seem to use the expanding mandrels unless I just keep missing them , instead of bushings you would get the neck tension you want all while resizing your case instead of two steps you would only need one step resize and done .

Yeah, FL sizing + legit real mandrel in one step would indeed be the shit, but it can't really be done... The only way to pull it off would be to use brass where the brass thickness at the neck was perfectly consistent and since even brass that gets annealed every firing still has a little bit of spring-back in it, it'd just be a constant PIA to try and run say 100 cases through something like that, brass any thicker would get stuck, thinner brass wouldn't get sized properly... so two steps it is.

That said, some guys use a body die followed by a Lee collet die to accomplish almost the same thing as using a mandrel die in the second step... but a Lee collet die neck-sizes-only, and arguably it's not great for concentricity to size the bodies and necks in two steps with separate dies, but some sort of "FL Lee collet die" might do the trick... but to my knowledge nobody makes anything like that currently that I'm aware of..?

 

[Steel head]

Run it up though a Lee collet, one of the best Lee products made.

Pulling to size size neck with a mandrel is more problematic than pushing a mandrel in.

 

[FLIGHT762]

That said, some guys use a body die followed by a Lee collet die to accomplish almost the same thing as using a mandrel die in the second step... but a Lee collet die neck-sizes-only, and arguably it's not great for concentricity to size the bodies and necks in two steps with separate dies,

I do just as you describe for two rifle calibers and my ammo has very low measured runout. Have you actually tried it?

 

[CK1.0]

I do just as you describe for two rifle calibers and my ammo has very low measured runout. Have you actually tried it?

Nope... that's why I said "arguably".

Honestly, I doubt it matters much, and I'm not entirely convinced concentricity is as big deal as some guys make it out to be anyways... and besides, I feel like once one is taking the time to work this into their process, single digit SD's are within one's grasp.

Supposedly/arguably, in a theoretical pecking order of "best practices", seems most would probably agree the list would shake out something like this:

poor = what's a mandrel..?

ok = FL sizing die, followed by either a mandrel die or a Lee collet die (either way works, also works the shit out of the brass, but is still probably better than any expander ball as far as providing more uniform necks and thus more consistent neck tension)

good = body die, followed by Lee collet die (-.001" under bullet OD mandrel, though many guys go to an undersized mandrel for -.002"), arguably/supposedly since the body and shoulder/neck aren't being sized while in alignment (like they would be in a one-piece FL die) concentricity can be less than ideal (arguably/supposedly).

better = FL bushing die (with appropriate bushing for -.002-.003" under loaded round OD), followed by mandrel die (-.001-.002" under bullet OD), since only the minimum sizing needed is done in a one-piece die and then all the mandrel does is open up the neck, the necks are worked very minimally and the effects are very consistent and repeatable. The bushing design is a compromise, bushings don't truly float and they aren't 100% rigidly connected either, so they cannot size as much of the neck and always be in exactly the same spot every single time like a true 1-piece FL die's neck can.

best = custom honed FL die (neck OD -.001-.003" loaded round neck OD), followed by mandrel die. No overworked brass, body/shoulder/neck sized all at once and with 1 rigid piece, only thing the mandrel has to do is make sure the neck ID is perfectly round and maybe push a thou or so.

To me, seems the less heavy handed one is with the shoulder/necks, the more consistent and repeatable the neck tension (especially if one anneals every firing), the better ammo you end up with.

Someday I'll try the honed FL die... but it's a 16 week wait or something like that, and the bushing die has been good enough for SD's in the low single digits... so IDK if I need to split more hairs at this point, but who knows...

I mean, my gun and ammo are already good enough to where it's already always my fault. If I can get an SD of 4, vs a 5, it won't change much, I'll still suck the same amount.