Neck turning, before or after fireforming, before transitioning to bushing neck sizing for sure

[cdherman]

OK, plan is headed towards 280 AI. But I am leaning towards buying some nice RWS brass in .280 Remington and fireforming out to 280AI.

I am also getting a set of Redding Competition Bushing Neck sizing dies. I've never used bushing neck dies before, but my understanding is that uniform neck wall thickness is pretty important, since of course there is no expander ball in play anymore.

I found several posts that recommend turning virgin brass (its softest).

Do you think its safe to assume that the RWS 280 rem necks will be uniform enough on the interior dimension that I can just turn them (aiming to take only enough off to make them uniform), or will I need to run an expander ball through them all once, then turn.

And the expander ball. The Redding set doesn't have one. But I should be able to just dial out any 284 expander so that the neck/body are not sized at all, just the ball entering the case and exiting to smooth out any dings or nicks before turning.....

I *could* order a Redding FL die with conventional expander ball to go with the comp set. They are "on sale" at Midway. Only $40 or so. But why? If any old 284 expander will do (I have 7 mag and 7 SAUM with expanders)

If it matters, my neck turner is a Forester Classic.

 

[J E Custom]

Re: Neck turning, before or after fireforming, before transitioning to bushing neck sizing for

OK, plan is headed towards 280 AI. But I am leaning towards buying some nice RWS brass in .280 Remington and fireforming out to 280AI.

I am also getting a set of Redding Competition Bushing Neck sizing dies. I've never used bushing neck dies before, but my understanding is that uniform neck wall thickness is pretty important, since of course there is no expander ball in play anymore.

I found several posts that recommend turning virgin brass (its softest).

Do you think its safe to assume that the RWS 280 rem necks will be uniform enough on the interior dimension that I can just turn them (aiming to take only enough off to make them uniform), or will I need to run an expander ball through them all once, then turn.

And the expander ball. The Redding set doesn't have one. But I should be able to just dial out any 284 expander so that the neck/body are not sized at all, just the ball entering the case and exiting to smooth out any dings or nicks before turning.....

I *could* order a Redding FL die with conventional expander ball to go with the comp set. They are "on sale" at Midway. Only $40 or so. But why? If any old 284 expander will do (I have 7 mag and 7 SAUM with expanders)

If it matters, my neck turner is a Forester Classic.

I am one of those that recommend turning virgin brass before it is fired. Not because it needs to be thinned, but because it needs to be the exact thickness so when it is fired, it will expand uniformly
and the bore of the case will be concentric to the bore. (If the case neck thickness is one or two thousandths different, after the case is fired the inside of the case neck will be off set from the bore by that amount and line the bullet up with the bore wrong effecting accuracy.

Once it is fired, it is very hard to correct this offset.

PS: There is nothing like "GOOD" tools and the difference in price will normally pay big dividends
in accuracy.

J E CUSTOM

 

[Mikecr]

Re: Neck turning, before or after fireforming, before transitioning to bushing neck sizing for

Your turning system would include neck expansion(of new brass) to fit the turning mandrel properly.
If it doesn't, I recommend getting a better system that does.
I only turn new brass, and I use a Sinclair turning system expander mandrel before seating bullets, in place of any other die 'expander ball'.
Whether FL sizing necks(which I would never do), or partial length sizing of necks, it's beneficial to pre-expand them (pre-seating) before bullet seating. This drives any thickness variance outward, away from seating bullet bearing, to lower runout. It also biases tension(bullet grip) inward, instead of outward, so that tension would grow over time(aging ammo) rather than drop. And finally, it reduces seating forces, which allows for more accuracy in CBTO.

 

[dok7mm]

Re: Neck turning, before or after fireforming, before transitioning to bushing neck sizing for

cdherman, I also turn my brass prior to fireforming. I use only K&M tools, so I'm not sure about the Forster setup. The normal procedure is to use an expander mandrel to true neck dings and size necks to .001" over your turning mandrel size. It is best to use expander and turning mandrels from same company, so you have consistent clearance of neck on turning mandrel. Remember to FL size and trim cases to same length if your Turner indexes off end of neck, as most do. Good Luck

 

[cdherman]

Re: Neck turning, before or after fireforming, before transitioning to bushing neck sizing for

The Forster setup has a hardened turner pilot that is sized .002 under the given bullet size. It is assumed that you have sized the neck and pulled the expander ball back through. It is noted in Forster's instructions that "the industry norm is to expand the neck back to about .001 UNDER the desired bullet diameter with the expander for adequate grip on the bullet" Thus they size their pilot .002 below bullet diameter.

Sounds like Sinclair asks for a special mandrel that expands the inside a little larger for their turner. I assume afterwards you then follow the process with a bushing neck sizer to get it back down to hold the bullet?

Thanks for the replies thus far. Sounds like I am on track with turning the necks (if necessary) at the very beginning. I have the Sinclair neck thickness gauge too, so I am not blind in that regard.......

 

[243winxb]

Re: Neck turning, before or after fireforming, before transitioning to bushing neck sizing for

Your type of outside turner requires that the brass is full length resized first, in a standard die, using the expander , before turning. This is after the brass has been fired in your rifle.



Cant use a bushing die.

1. Fire form
2.FL size in standard die, pushing the shoulder back fully.
3. Turn to shoulder. Load and fire.
4. For the next loading, a bushing die may be used.

I use Redding FL type S bushing die for 243 win and outside turn using a Lyman. The Lyman works about the same as the Forster unit.

 

[Welderboy11972]

Re: Neck turning, before or after fireforming, before transitioning to bushing neck sizing for

I also use the Sinclair neck turning mandrels to neck size. My .257 mandrels are .256" for the neck sizing mandrel. .255" for the turning mandrel. It's the same on the .308 mandrels. ( .307" neck, .306" turn) I would assume that you could get different sizes. I just haven't looked.

I use the neck mandrels to neck size. ( after I've turn the necks when they were new brass)

Neck size in my redding neck die ( no expander ball)
Neck up with the neck mandrel ( in the die from Sinclair)
It will almost set bullets with the weight of the handle of my press.

A bushing die might work better, because you can change bushing sizes to neck down. It would work your brass less.

This has given me the best results as far as neck sizing my brass. It also helped to lower my ES and SD.

 

[cdherman]

Re: Neck turning, before or after fireforming, before transitioning to bushing neck sizing for

Your type of outside turner requires that the brass is full length resized first, in a standard die, using the expander , before turning. This is after the brass has been fired in your rifle.



Cant use a bushing die.

1. Fire form
2.FL size in standard die, pushing the shoulder back fully.
3. Turn to shoulder. Load and fire.
4. For the next loading, a bushing die may be used.

I use Redding FL type S bushing die for 243 win and outside turn using a Lyman. The Lyman works about the same as the Forster unit.

Forster actually says only neck sizing is needed before turning. I would think that it is important to size the neck ALL the way to the shoulder in a fired case -- otherwise, the outside turner would cut more brass off, over the unsized area of the neck and make it weak.

I assume that you feel a full length resizing will leave the neck more concentric and centered to the body of the cartridge? I don't quite follow that a FL resize is needed. So long as the inside diameter of the entire neck has been determined by a mandrel or expander ball, why would it not be OK?

Obviously, when you outside turn brass, the variation in wall thickness needs to be on the outside. The forster turner pilot is about an inch long and forces the entire neck of the cartridge into a fixed rotation while turning.

I'd rather not work my brass with a step that is not definitely needed. Once I'm fireformed to the 280 AI, I intend to size the body only if I'm having feeding issues, and even then, I will bump the shoulder only 1-2 thousands.....

 

[243winxb]

Re: Neck turning, before or after fireforming, before transitioning to bushing neck sizing for

My Lyman instructions say FL size before turning.

The point where the shoulder and neck meet, may be different between fired/neck sized and FL sized, pushing the shoulder back??

Follow your instructions. Good luck.

 

[J E Custom]

Re: Neck turning, before or after fireforming, before transitioning to bushing neck sizing for

Sounds like Sinclair asks for a special mandrel that expands the inside a little larger for their turner. I assume afterwards you then follow the process with a bushing neck sizer to get it back down to hold the bullet?




The Sinclair tool uses a truing mandrel to size the neck ID to perfectly match/fit the turning mandrel. This process assures there is a perfect fit on the turning mandrel so there wont be
any run out during turning.

When turning is complete you can neck size if necessary. The Sinclair neck sizing mandrel
is .001 thousandths smaller than the bullet diameter. And the turning mandrel is .002 smaller than the bullet so sizing may not be necessary.

J E CUSTOM

 

[Mikecr]

Re: Neck turning, before or after fireforming, before transitioning to bushing neck sizing for

cdherman, you're right in your understandings of this.
Unless special forming for a wildcat, FL sizing of necks, and fire-forming prior to turning -is undesirable. In fact, you lose one benefit of turning right off the bat, with turning necks that are not new. That is, donut mitigation.

The Sinclair system is just that, a system, and there is no better system today. It's no different in function than described by Forster, except with Sinclair you're not relying on outboard components to get the job done(which could cause problems).

New brass comes with donuts inherent to it's manufacture, just very small at this point. It's easiest to address with no action other than mandrel expansion and turning. Don't bother downsizing, trimming, annealing, or any other actions that serve only to muddle up a simple job.
I have never used or needed any case stop in turning. I just eyeball a slight shaving at the neck shoulder junction, and this works fine.