mandrel for case necks...can somebody please explain

[FEENIX]

KISS

This is a hunting forum isn't it? And the kind of accuracy needed to hunt at extended ranges only has to be the size of a paper plate, correct? Closing the gap a bit is fine but how far do you have to close that gap ???

You are the one that criticized the presenter. So if you can do a KISS version lets see it.

 

[Mike Matteson]

For 1 your neck generally not totally round. It's thickness can vary. So by sizing only the outside, pushes the different inside. If you are using standard chamber the I.D. is factory set. If using an aftermarket chambering it may be reduced. The flip side is you push the uneven thickness to the outside, then that portion of the neck hits the chamber wall quicker and pushes the bullet to one side going down the barrel. Now I haven't turn enough high end brass (Peterson, Lapua) to full determine if the neck thickness are even or not all the time. I know that other large manufactures, like Winchester and Rem. and others their necks can be greatly out of round.
Now this is how I do it. New case never been fired. I set up and cut the case to length so the cases length are all the same. Reason why? In cutting the neck for thickness you need to stop at the transition from neck to shoulder so they are all the same. You don't want to over or under cut the necks. So set up to cut the thickness stops at the same place each and every time. They need to be all the same. I cut all the necks for thickness. Depending on your chamber sizes would be just how much you take off the thickness. Now you generally don't go below .012 in thickness. That way you have even tension all the way round the bullet. Your neck is perfectly round so it doesn't kick the bullet one way or the other as the neck expands when fired. From my understanding match shooter FL size there cases, but they only bump the shoulder by about .002. Annealing is another thing. I anneal every time. There are other steps I haven't included in this post. there is a lot of work in setting up your case to start with. Once done a lot of work is done.

 

[sedancowboy]

if I neck size with a bushing wouldn't it work the neck brass less?
So, let me see if I understand you all...
For best accuracy..less run out. You run a bushing over the neck while full length resizing the case body. Then- use a mandrel to push inside the case neck leaving the inside diameter the preferred dimension for neck tension..say around .002 less than bullet diameter.
Reasons being the expander ball on most dies increases runout- at least more than the mandrel does. Is this right?

Answer to your first question is Yes. If you don't use a mandrel at all you will work the brass less. But and the reason we use mandrels is that when you use a bushing to set neck tension the brass remembers which direction you pushed it. So if a bushing is pushing in then it is going to want to spring back out over time. Now we are talking as small amount of spring back may .001. The Mandrel also has the advantage of pushing the brass out and so the brass will grip the bullet better. Plus the variance in the wall thickness is pushed to the outside. In all reality unless you are turning necks and annealing all this is a mute point.
I shoot for .002 neck tension. so I use a bushing .003 smaller that a loaded round measures at the neck and then use a Mandrel that is .002 smaller than bullet diameter.
Example is .308 bullet diameter + neck thickness of .014 + .014 = .336 measured dia of a loaded round. Now subtract .003 for a bushing size of .333. I then would use a Mandrel of .306 to set finial neck tension. I always error on the smaller size so if your neck is not quite .014 then use a .332 bushing.
Hope that helps.
Henry

 

[milboltnut]

if I neck size with a bushing wouldn't it work the neck brass less?
So, let me see if I understand you all...
For best accuracy..less run out. You run a bushing over the neck while full length resizing the case body. Then- use a mandrel to push inside the case neck leaving the inside diameter the preferred dimension for neck tension..say around .002 less than bullet diameter.
Reasons being the expander ball on most dies increases runout- at least more than the mandrel does. Is this right?

Not necessarily. Chamber/case alignment is more important.

yes... dial indicate and see.
Just in case you are wondering if it's accurate, I put a pin gauge on it and it barely moves off zero.

 

[The Oregonian]

KISS

This is a hunting forum isn't it? And the kind of accuracy needed to hunt at extended ranges only has to be the size of a paper plate, correct? Closing the gap a bit is fine but how far do you have to close that gap ???

Guys like him make it sound like you have money to burn, and that you need this and you need that. For 14 bucks I made a bullet seating indicator, for 22 bucks I made a concentricity tool, for 189 bucks I got a FA coax instead of 300+ for Forester coax, wasted money on 21st century mandrels, die, and Forsters FL dies instead of getting Redding standard die sets which the seater is better than Foresters BR seaters believe it or not. See where I'm going with this? Am I too long winded ? Should I get a honed Forster FL die and when I buy a new lot of brass have to get another die honed or just do a body die and collet die ?

There's my KISS version FEENIX

A paper plate gets awfully small when you get way out there. And the better accuracy you get with the load and gun the more margin for error there is with wind, etc.

You are arguing about cost and delivery of the info which is just getting off topic.

 

[milboltnut]

A paper plate gets awfully small when you get way out there. And the better accuracy you get with the load and gun the more margin for error there is with wind, etc.

You are arguing about cost and delivery of the info which is just getting off topic.

You don't have to spend a small fortune to get good results

 

[FEENIX]

You are arguing about cost and delivery of the info which is just getting off topic.

Yep!

 

[The Oregonian]

You don't have to spend a small fortune to get good results

You are the only one bringing that up…i don't think anyone is arguing that
you have to spend a small fortune. The question was about mandrels and runout.

 

[milboltnut]

those videos lean towards buyin more than you should, next thing you know questions come in about needing this and needing that.

 

[The Oregonian]

You just can't help yourself, can you?

 

[Shawn Carverelli]

Yep!

You just can't help yourself, can you?

its fairly easy to follow the money. Youtube pays for these videos. They get the money from the manufacturer. As the consumer, we need to decifer through the BS

 

[milboltnut]

You just can't help yourself, can you?

Yeah I help my self by not watching the promo videos and to be suckered in. Explaining is good enough, without, the videos.

 

[milboltnut]

this is pretty new and I might be a little slow.
I understand the theory of turning necks, neck sizing without full length suze and full length plus using a neck bushing to resize a neck to customize neck tension on a bullet.
However, I hear talk about using a mandrel that pushes into the neck. I don't understand why one would want to do that if you can resize the neck from the outside.
Can somebody walk me through this? I've reloaded my own ammo for 25 years, but this seems odd to me.

mandrel are supposed to create less runout verses bushings. Debatable whether a little runout effects accuracy, and if it's worth it using mandrels over bushing. Choice is yours. Buy both and see. Easy explanation ?

Summed up in one reply.

 

[The Oregonian]

I use both bushing and mandrels….3 thou under with bushings, 2 thou under with a mandrel.