Neck vs. Full Length sizing for Accuracy in .308 win


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hsiddall
February 1, 2008, 11:51 AM
Well here we go, This may well be one of the worst questinos to ask here but what is better in regards to accuracy and why. I also read on a decription for a comp seating die thano crimp is needed is this true?

Sorry, I should add that this is for a remy 700p and all the cases are once fired from this gun...

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USSR
February 1, 2008, 03:11 PM
hsiddall,

I have a Redding Competition Die set (micrometer necksizing die, body die, and micrometer seating die) in .308, and here is how I do it:

After cleaning the brass, I remove the spent primer using a Lyman Universal Decapping die (the decapping pin and expander ball being removed from my necksizing die). I then run the brass thru my body die, which is adjusted to bump my shoulder back about .002". After removing the Imperial Sizing Die wax, I then insert a Redding TiN bushing in the necksizing die which will give me about .002" neck tension and run the brass thru this die. The Titanium Nitride bushing requires no lube, and since I am not dragging an expander ball thru the neck, no lube goes on both the outside and inside of the neck. After repriming and adding the powder charge, I seat the bullets to the maximum length that the magazine can handle, as long as the cartridge base to bullet ogive length is shorter than the same measurement in the rifle. And, I NEVER crimp rifle ammo.

Don

Lennyjoe
February 1, 2008, 03:13 PM
Full size if its non fired brass from your rifle. After it's fireformed from your rifle then use the neck sizer.

Other opinions vary but that's what worked best for my -06 and 22-250.

Bad Flynch
February 1, 2008, 03:22 PM
Nothing wrong with the previous method, but Redding now has a shoulder-bump die that holds a TiN neck sizing ring, so two steps are no longer needed. A very small shoulder bump is a good idea and the sizing produces a more uniform case so that the induced error is constant. Once an error is constant, it can be compensated for.

Snapping Twig
February 1, 2008, 03:28 PM
Once it has been fireformed in your rifle, neck sizing allows best accuracy as the cartridge fits your specific rifle's chamber fully and is totally supported due to the tight fit.

Drawbacks...

Neck sized ammo may not fit other rifles chambered for the same round. If you have the ability to segregate ammo for specific firearms, then you're good to go.

Neck sized ammo may work in another firearm, but you have to find out by trying it.

I have several rifles in similar caliber, for these I full size. I'm not good enough a shot to exploit the difference and 1.5" groups are good enough for my needs.

USSR
February 1, 2008, 06:49 PM
Nothing wrong with the previous method, but Redding now has a shoulder-bump die that holds a TiN neck sizing ring, so two steps are no longer needed.

Bad Flynch,

The body die not only bumps the shoulder back, but also resizes the body on down to the web. In using the body die in combination with the necksizing die, I am essentially FL resizing my brass in two separate and distinct operations. I like the idea of separate dies for each operation.

Don

hsiddall
February 1, 2008, 09:40 PM
Lube necesary for the typical neck sizing die? I Know its needed for full length sizing. I just rdered aother lee fl die as I have a stuck case that aparently didint have enough RCBS lube on it and isnt coming out:cuss:. I also ordered Forester Bench Rest Neck size two die set along with my long awaited RCBS Precision Mic for .308 Win... Looking for 1/4 minute groups some day...:D

ranger335v
February 1, 2008, 10:08 PM
Should you lube for neck sizing? Sure. You can force it and it may look like you are getting away with it but anytime you have sliding contact and pressure between two metal surfaces they should be lubed. Dry rubbing will result in metal galling which causes tiny brass chunks to stick in your die's neck.

USSR
February 1, 2008, 10:10 PM
Lube necesary for the typical neck sizing die?

hsiddall,

Unless you are using a titanium nitride bushing or something similar, you will have to use lube when necksizing.

Don

dagger dog
February 3, 2008, 03:15 PM
being fairly new at reloading,
i shoot a Ruger KM77VT MKII .308 Win. my first hand loads neck sized through Lee collet die, 125gr. Nosler ,Varget ,Win brass ,CCI large rifle primed seated to 02.80" gave me 1" @ 100 yrds.
i just about fell off the bench when the 5th round hit, could not believe that i could have loaded ammo that accurate. my first 1 ragged hole group.

i'm definitley a fan of necksizing but i have now shot groups similar to that one in the same rifle , with full sized brass and the rest of the load the same as stated??????

something to ponder

daggerdog

30Cal
February 3, 2008, 09:09 PM
The affect of how you size on accuracy is down in the noise. If you're not shooting top of the line match bullets, and more importantly, aren't a first rate shooter, then you aren't going to be able to detect a difference.

Crimping is seldom done among highpower shooters. I don't know about the benchrest guys, but I don't think many of them crimp either.

Jake in TX
February 3, 2008, 10:11 PM
Hsiddall,

Lubing depends on the die. If you are using the Lee collett neck sizing die, no lube is required.

Decide if you want to crimp. I don't, many don't, many do. However, crimping will affect how a load works in a given firearm. In other words, develop your load either crimping or not crimping.

Jake in TX

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