Full Length Die Concentricity Question--Any Caliber

[kraky1]

I didn't mean to knock his experiment. The writer of that article is a super famous name in the sport and has forgotten more about it than I'll probably ever know!!
I'm just saying it was a little wierd that testing "hunting" caliber plain jane seating dies at a case neck tension that you wouldn't normally get from the "partner" sizing die that would go with it.
As he proved even a plain jain RCBS does a pretty good job of seating with a tension of .002"
I know that after changing the mandrels on my lee collet dies to make more tension rcbs dies (and others like it) quickly start producing less stellar results seating. If you add another problem common today which is fancy bullet tips that don't match the "cup" in the seating stem it can really get nasty in a hurry.
All this is why its fun to have the concentricity checkers to see how well your brass is doing after sizing.....and then after seating. Whether or not it really means a huge difference to ALL guns becomes another can of worms real quick cause runnout does not necessarily make a big difference in all guns.

 

[Oldtrader3]

Run out does assure bullets that stabilize sooner and fly better. I am guessing that this will matter at longer ranges.

 

[ElmerThud]

Absolutely OT3. The better a bullet is made to fly the more confidence you can have at longer ranges with the load.

Kraky1 is right though when he points out that the cup in many seating stems may not match the shape of modern poly tipped bullets in use today. That in itself as he says, may well introduce a completely unexpected problem with run-out.

My view is there are so many demons to chase when trying to achieve consistency with reloaded ammunition, there has to be a 'good compromise' for hunters. I'm not a BR shooter and so much of what they do is beyond the time and effort I'd willingly employ for my sport.
Having said that, I'm no slouch when it comes to reloading and I have some eye for detail, so I just choose the basic demons to chase.
ATB ET

 

[Oldtrader3]

ET, I look at how well factory ammo shoots today and that makes me not worry as much about picking the FS out of pepper in my loads. The is a critical balance of care and attention to detail in handloads, beyond that is obsessive-compulsive. BTW, I own and use fairly often a RCBS Universal gauge setup for headspace and bullet TIR.