what neck turning tool do I need not for f class shooting?

[Sniper338]

Doesn't sound like you need a neck turner at all.

 

[Bc'z]

Doesn't sound like you need a neck turner at all.

Sounds like a bushing die is in order.

 

[milboltnut]

Doesn't sound like you need a neck turner at all.

you read my mind.... !

 

[Evan]

1- Does the expander ball form a donut? And will a forster FL die prevent that?
maybe I should go with a forster type FL die... seems Forster FL's are dried up.
2- I'll do what Even said, measure the neck after firing to see if my factory chamber neck area is generous....

A donut usually is caused by the normal process of brass flow. It goes a little like this: You fire a case and it expands some. You size it and push the shoulder down a few thousandths. Some of the brass that was the new expanded shoulder is now the base of the neck. Each reloading cycle, that brass buildup in the base of the neck gets more substantial. If your seated bullets are above that junction, you may never notice it. If you seat bullets deep enough in the case, then you will start to feel it both when you size brass, and when you seat bullets. This thread of mine may interest you: https://forum.accurateshooter.com/t...do-you-think-this-is-a-donut-forming.4028810/

Many folks have a hard time with expander balls. I run them in my dies, but I use REALLY light neck tension and don't feel the expander ball on the down stroke of the press unless there is a problem. I leave it in to catch any dents, donuts or other changes in the neck, and to make sure the mouth of the case remains entirely round.

 

[milboltnut]

Evan, thanks for your patience with me.

So you use a bushing FL die and utilize a expander to smooth out any possible perfections, got it.

Would donuts cause pressure spikes?

 

[Bc'z]

Evan, thanks for your patience with me.

So you use a bushing FL die and utilize a expander to smooth out any possible perfections, got it.

Would donuts cause pressure spikes?

Use a bushing die without an expander.
Bushing will not size bottom portion of neck, you'll never know the doughnut even exists, use a smaller bushing than desired tension, then expander mandrel to proper tension/interference fit.

 

[milboltnut]

Use a bushing die without an expander.
Bushing will not size bottom portion of neck, you'll never know the doughnut even exists, use a smaller bushing than desired tension, then expander mandrel to proper tension/interference fit.

I usually stay away from the donut with short seating depths. But good to know.

 

[LHSmith]

why's that? make accuracy worse?

I missed your question, it was hidden among your rest and bags pics.
The reason I don't believe in neck turning for factory rifles is that it never worked for me and I believe degraded accuracy. In a factory chamber the tolerance stack-ups allowed in both chamber and cartridge ( the cartridge dimensions being influenced by the re-size die) allow for the cartridge to lay in the chamber on a cant ( i.e. crooked)-----it cannot truly align itself with the bore. Don't forget the ejector is pushing the back of the case with some force also biasing the direction of the cant. This misalignment causes the bullet to enter the throat askew ( i.e crooked) which in turn engages the rifling canted. IMHO this has a much more negative effect on accuracy than any gains one will net from a tad more consistent neck tension. Granted a fully fireformed neck sized case would help with the alignment. but neck sizing has too many disadvantages for my intended use. Removing neck material in this case could increase the amount of cant.

 

[Sniper338]

you read my mind.... !

I just say that because you have factory rifles. There's no benefit in it when its sloppy factory chambering. You dont have tight necks where you have to to get brass to fit, and its really probably the opposite. You probably have plenty room around the neck in the chamber as is to where turned or not turned itd make no difference

 

[milboltnut]

I was under the impression it was more about bullet neck tension and bullet release.

 

[Dusty Stevens]

I was under the impression it was more about bullet neck tension and bullet release.

It is thats why any rifle will benefit. Its about consistency in any place you can get it. Eliminating variables not ignoring them because you have a factory chamber. Its about making the most consistent ammo

 

[LHSmith]

I was under the impression it was more about bullet neck tension and bullet release.

You apparently failed to read or comprehend my post #88 ............or you don't believe it valid.

 

[milboltnut]

You apparently failed to read or comprehend my post #88 ............or you don't believe it valid.

didn't say all about neck tension and bullet release said mostly so yes a formed case is needed. But not fully fire formed. Then you have extractions issues.

 

[LHSmith]

didn't say all about neck tension and bullet release said mostly so yes a formed case is needed. But not fully fire formed. Then you have extractions issues.

That's what you discerned from my post? Not at all what I said. I want to help but I feel I am wasting my time. You won't even say what rifles you hope to achieve 1/2" moa.
Again I feel suckered into this troll routine.

 

[milboltnut]

I just measured my fired case...... and it's .340 and SAMMI shows .3404.... I'm right there it appears. I guess That my factory chamber is as loose as you think.

 

[Evan]

Evan, thanks for your patience with me.

So you use a bushing FL die and utilize a expander to smooth out any possible perfections, got it.

Would donuts cause pressure spikes?

Yep, I use FL bushing dies and start at 0.001 under my loaded round diameter for the bushing - so I use a 0.289 bushing if my loaded rounds measure 0.290. This is way lighter than I would recommend for a hunting rifle or factory gun and is used only for my BR rifles where the rounds are handled with care at all times. My hunting and factory rifles all use regular FL dies and I do not worry about these things with them.

I've never experience pressure spikes as in a load gets hotter or the muzzle velocity is significantly different, but you can really feel it while seating a bullet and a BR gun will lose it's fine edge of accuracy.

I disagree with LHSmith. A cartridge will always center in the chamber on the shoulder - any headspace is taken up when the firing pin pushes the cartridge forward until it stops. A "loose" fit of the cartridge to the chamber will not effect how it centers relative to the bore.

EDIT: Here are a couple drawings I made a ways back to show what I mean about centering on the shoulder: https://forum.accurateshooter.com/threads/concentricity-question-help.3980767/post-37513960

 

[LHSmith]

I just measured my fired case...... and it's .340 and SAMMI shows .3404.... I'm right there it appears. I guess That my factory chamber is as loose as you think.

Now think about this. We are talking about a loaded round, NOT a FIRED case. It will not allow the bullet to align with the bore....bullet enters rifling crooked.....goes down the barrel crooked.....enters open air in yaw (crooked)....arrives on target with greater group dispersion than if fired without the yaw induced.

 

[LHSmith]

Y

I disagree with LHSmith. A cartridge will always center in the chamber on the shoulder - any headspace is taken up when the firing pin pushes the cartridge forward until it stops. A "loose" fit of the cartridge to the chamber will not effect how it centers relative to the bore.

If this were true, then an awful lot of us competitors could forgo custom actions, and simply build off untrued factory actions.
My work is done here, I am out.

 

[milboltnut]

With the measurements I gave you, could have recommended a bushing?

 

[PopCharlie]

When I was first doing my research, I was very torn between the k and m unit and the 21st century. The I was very close to purchasing the k and m because of the pilot jack and the ability to add a dial indicator. These features made a world of sense to me. What ultimately won me over with the 21st century was the ability to easily transition the cutter to a motorized unit. I have since made that transition and do not regret it a bit, as said above neck turning is one of the least enjoyable tasks.

I've not seen neck turning with factory chambers make accuracy worse. It is a nice way to produce both lighter and more consistent neck tension with factory dies though. The drawback in a factory chamber is that neck clearance is usually quite generous, so if you turn your necks you may now have even more, say 0.010" or more of clearance which will work the brass more with each firing cycle and shorten its life.

If your goal is to shoot 0.5MOA consistently, Id recommend high quality, match type bullets first. If that doesn't do it, then I'd try high quality brass (if you aren't already: Lapua, Peterson, ADG, Alpha), then as the final step; I'd get a new barrel. Neck turning isn't something I would put in the "shrinks large groups" category. It's more in the "creates more consistency" category.

I agree with Evan. There are really only 2 reasons to neck turn, Both improve consistency. 1 reason is to correct variations in neck wall thickness and reduce the possibility of a doughnut. The other reason is if you have a tight necked chamber. For this reason, it is a matter of necessity. However, it does improve consistency to have necks turned to the same thickness.

PopCharlie