What's Wrong with Neck Sizing?

[ddjchemist]

I reload for multiple calibers and I only use FL resizing. However, because of my curiosity, I tried neck sizing for my 6.5CM rifle. I took 5 Lapua cases that were shot just once (of course shot in the same rifle that I am reloading for), did neck sizing following Redding manual (neck was resized about 2/3 way). I tried all five cases after neck resizing and they were all going smoothly and bolt was easily closing. However, after I seated bullets on all five cases, not one wanted to chamber. The bolt did not even get near to get closed. The issue was not too long bullet seating because even after I pushed bulled deep inside, the cartridge would not close. After pulling the cartridge back, I noticed scratch mark on just one side of bullet. It seemed as if the case was not straight and as if there was some concentricity issue with the cartridge. I felt like bullet was hitting throat. All FL sized cases as well as factory ammo goes smoothly and the rifle is super accurate (just had new Krieger barrel installed), so the issue is not rifle chamber. I guess there is a reason many advise to avoid neck sizing. Any input would be appreciated.

Dan

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[po18guy]

Are you using a neck sizer, or just backing the FL sizer die off? "Neck sizing" is intended to size the entire neck. You might like a LEE collet neck sizing die. It sizes the neck to a centered mandrel of bullet diameter (-.002' or so).

 

[ddjchemist]

Are you using a neck sizer, or just backing the FL sizer die off? "Neck sizing" is intended to size the entire neck. You might like a LEE collet neck sizing die. It sizes the neck to a centered mandrel of bullet diameter (-.002' or so).

I was just using Redding Neck Sizer (Premium die series). I tried one case to resize neck all the way, and still can't chamber. I am convinced that just neck sizing negatively affects case concentricity (I think I read this somewhere). It is not a big deal. I always did FL sizing for my reloading and neck sizing was just a curiosity trial for me. Some top bench shooters advise avoiding neck sizing and I think I see now why.

 

[po18guy]

I would call Redding and ask to speak with a tech. As you know, their customer service is above reproach.

 

[oremike]

The whole of the neck needs to hold the bullet, not just 2/3ds. The die should just kiss the shoulder to be adjusted right.

 

[lcb97269]

The brass might not be concentric. Might need neck turning. I neck size nearly everything and have had problems with my Savage 10fp after several loads. Crap happens. Too many things can cause crap to troubleshoot here.

 

[ma96782]

You ARE talking about a true "bolt action gun" and NOT a semi-auto Rrrrrright?

BTW.....some people have also tried running their brass into the die. Then giving the case a maybe 90-180 degree twist then running it up again.

Or

Hell, just do the full length re-sizing and call it GTG.

Aloha, Mark

PS.....I tried neck sizing only and I ran the case into the die until all of the neck was sized (NOT just 2/3 way up the neck). I could tell by where the case lube line was.

BUT of course, guns/chambers/brass, etc....etc.... vary.

Then......YES, brass case concentricity (and bullets) can also be a problem too. Not to mention the bolt head and case head actual positioning upon firing.....making a difference with accuracy.

 

[Spitpatch]

The whole of the neck needs to hold the bullet, not just 2/3ds. The die should just kiss the shoulder to be adjusted right.

I would agree that the portion of the neck that is capable of holding the bullet should be doing so. (Often the neck is a bit longer than the contact portion offered by the bullet at its operating seating depth.)

With true neck sizing (or partial sizing to just allow chambering), a portion of the neck may remain in its "fired" diameter. There is a school of thought claiming this "untouched" portion of the neck (already fire formed to the neck portion of the chamber) can aid in concentric positioning of the cartridge.

 

[Member 34319]

I had great results neck sizing for 223. Brass life was superior when neck sizing.

I want to try it for 6ARC. No true neck sizing die exists for it yet.

Concentricity might be a concern.

I'll definitely be watching here to see what the actual culprit is as I'm really interested in hearing about what's happening. Weird to hear that the cases chamber after neck sized yet not when a bullet is seated.

I wonder if it's the seating die that is off? Which die is being used for seating?

Hope you find the problem, other than brass life, I got 223 down to .25" groups at 100, i account neck sizing only as part of that success.

 

[oremike]

Just a silly question but are you sure that you are using 6.5 bullets and not 6.8 bullets. It would be easy to grab a box of 6. creedmore something and get the wrong box. Also are you feeding the round out of the magazine? You mentioned a new barrel and some only like the fed from the magazine due to the extractor set up.

 

[ddjchemist]

I am using .264" Lapua Scenar bullets in Tikka Tac A1 Bolt Action rifle with Krieger Heavy Varmint 1:8-twist 4-groove SS 24" barrel. I think I might know what is going on. Neck sizing shrinks upper part of the neck, but the area of the neck just above the shoulder bulges and becomes wider than it was after fire-shaped. Anyway, I am back doing FL sizing and it is all good. At least I learned a lesson NOT to do neck sizing.

 

[pharmseller]

I only neck size. .223, 7mm-08, 7mm Rem Mag, .30-06. Multiple rifles in each chambering.

I use the Lee collet neck sizing die.

I have no problem with anything chambering, as long as the case came from the same rifle.

 

[Mikej]

I am using .264" Lapua Scenar bullets in Tikka Tac A1 Bolt Action rifle with Krieger Heavy Varmint 1:8-twist 4-groove SS 24" barrel. I think I might know what is going on. Neck sizing shrinks upper part of the neck, but the area of the neck just above the shoulder bulges and becomes wider than it was after fire-shaped. Anyway, I am back doing FL sizing and it is all good. At least I learned a lesson NOT to do neck sizing.

How much is the shoulder getting bumped back?

I don't get what "Bulge" you'd be talking about? If you are raising the die just to the point there's no shoulder bump, the neck would be sized the full length. Minus .001"-.002" at the base of the neck. That could hardly be considered a bulge. Is there a chance as the expander ball comes out of the case it's pulling/stretching the neck up and the shoulder where the neck ends is elongated and hitting first?

I started not bumping the shoulder on the 6.5 Swede Mauser by backing the die out some because it chambered with just kissing the shoulder in the chamber.

It could be that these artsy-fartsy Modern bolt guns have a lot tighter specked chambers than a 120 YO bolt gun huh?

 

[ddjchemist]

How much is the shoulder getting bumped back?

I don't get what "Bulge" you'd be talking about? If you are raising the die just to the point there's no shoulder bump, the neck would be sized the full length. Minus .001"-.002" at the base of the neck. That could hardly be considered a bulge. Is there a chance as the expander ball comes out of the case it's pulling/stretching the neck up and the shoulder where the neck ends is elongated and hitting first?

I started not bumping the shoulder on the 6.5 Swede Mauser by backing the die out some because it chambered with just kissing the shoulder in the chamber.

Neck sizer does not bump shoulder. It only shrinks neck.

 

[P7M13]

Pictures of good rounds next to failed rounds please.
Didn't read the whole thread, but did you trim the brass to length?

 

[Mikej]

Neck sizer does not bump shoulder. It only shrinks neck.

Understood. But I thought you started by just backing the FL die off a couple/three thousandths? And that's when they wouldn't chamber.

 

[P7M13]

but the area of the neck just above the shoulder bulges and becomes wider than it was after fire-shaped.

Bushing die or fixed Redding?

• Too much squeeze (i.e. bushing too small of a diameter) will bulge the base of the neck
• Not enough travel will leave a fattening at the base of the neck
• Too long of a neck will hit a hard stop in some dies (Hornady are notorious), which will cause a bulge at the base of the neck or the base of the shoulder. Same with seating.

Some top bench shooters advise avoiding neck sizing and I think I see now why.

If you're referring to Erik Cortina's blog, do what works for you and your rifle.

 

[P7M13]

Bushing die or fixed Redding?

• Too much squeeze (i.e. bushing too small of a diameter) will bulge the base of the neck
• Not enough travel will leave a fattening at the base of the neck
• Too long of a neck will hit a hard stop in some dies (Hornady are notorious), which will cause a bulge at the base of the neck or the base of the shoulder. Same with seating.

If you're referring to Erik Cortina's blog, do what works for you and your rifle.

Edit to add, move the ram slowly, and for test, make sure you have good, light lube on the neck.

 

[ddjchemist]

Edit to add, move the ram slowly, and for test, make sure you have good, light lube on the neck.

Interesting, that is exactly what Redding said too. I wrote them. Anyway, I am jut going to FL size and forget neck sizing for the rest of my reloading life.

 

[Spitpatch]

Interesting, that is exactly what Redding said too. I wrote them. Anyway, I am jut going to FL size and forget neck sizing for the rest of my reloading life.

One adventure detoured should not discourage further journeys, Grasshopper.