308w neck sizing ?? vs full length

[turtlezx]

Does neck sizing produce better accuracy than full length resizing ??

[sawinredneck]

Depends, is this brass all going to be shot in one gun or several guns? If several then full length size them.
Is this brass going to be loaded in a single shot or bolt action rifle? If so, neck size is fine. If it's going in an auto the full length size it.
The gains in accuracy from neck sizing are there, but not as much as some would have you believe, it's mainly to keep from working the brass as much, getting more life out of it.
I can already hear the screaming, YES, if it's fire formed in the chamber of the SAME gun that it's to be shot in again, just bumping in the neck CAN show gains in accuracy, I won't deny it. But unless you are trying to put ten shots into a dime at 200yds benchrest shooting, most of us will never realize those gains.
You WILL see gains in brass life though.
Good and confused now?

[Artful]

:goodpost: - I couldn't have said it any better.

[sawinredneck]

:goodpost: - I couldn't have said it any better.

Well thank you very much sir! That is a pretty nice compliment.

[Wally]

I am not sure why brass would last longer being neck sized vs full sized. In my CF rifle shooting cases "fail" due to neck splits and I have yet to see any case life difference between neck vs. full sizing. As I understand it most bench rest shooters are now full sizing their brass.

[Larry Gibson]

sawinredneck hits it with; "But unless you are trying to put ten shots into a dime at 200yds benchrest shooting, most of us will never realize those gains."

Basically it means you have to have a rifle that can demonstrate the difference, the loading technique that can demonstrate the difference and the shooting ability to demonstrate the difference.

Full length sizing cases can defnately lead to short case life, as little as 3 - 5 firings per case in some instances. I haven't seen any bench resters FL size their cases, most don't even NS.

With bottle neck cases used for cast bullets and match/varmint loads with jacketed bullets I NS. Exceptions are with top end loads used in RF matches and semi- autos, then I FL size with RCBS X-dies. That includes loads for my lever rifles.

[Tom W.]

When I had my single shot Savage I shot a lot @ 300 yards or more. I found that neck sizing and Federal Match primers, along with a boat
tail bullet that my rifle liked would shoot wonders..
Sadly I couldn't do anything with cast.

[BK7saum]

I full length size all my cases. Most times those dies are bushing dies where I only size the neck the absolute minimum to just kiss the expander as it comes out of the case or without the expander on neck turned cases to give 0.001-0.002" neck tension. At the same time, the die is set up to bump the shoulder back about 0.001". I don't think I could improve case life at all by neck sizing only. I also anneal every 4th or 5th firing.

Depending on the die and chamber, the neck can expand from a couple of thousandths to 0.010-0.020" over bullet diameter, then be sized down by the die to 0.010" ID less than bullet diameter, only to be expanded back up to 0.003" below bullet ID by the expander ball. Universal neck sizing dies can be the worst. For example, a universal .30 cal neck sizer by a name brand manufacturer sized 300 Norma Mag brass down about 0.012-0.014" less than bullet diameter. It was very difficult to pull the expander ball back through a lubed neck. Since it was a universal expander, it was set up to size any .30 call cartridge neck. .30-30 has thin necks at times (0.010") and the 300 norma has thick necks (0.014-0.016"), which caused the necks to be extremely overworked. I ended up annealing after the first sizing and having a sizing die made to fit the .300 Norma cases being used. Now the brass only expands 0.002-0.003" on firing and is sized back 0.005" or so and a bullet seated.

Anyway, case life depends on the tolerances of the brass, chamber, die, and expander. The least amount of working the brass, the longer it lasts. So just because you are neck sizing only, don't assume that you are prolonging case life. You need to know how much you are working the brass.

Brad

[Larry Gibson]

The OP asked about the .308W. That case has minimal body taper and if using top end loads at 7.62 or .308W psi's FL sizing will get you incipient case head seperation, not split necks. In 7.62 gas guns that can happen in as little as 3 firings with standard FL dies, especially with 7.62 NATO spec chambers. Use of the standard .308W RCBS X-die will alleviate that and you can get 20+ firings per case (LC Brass) at full throttle.

In my .308W M70 Target and .308W Palma Match rifle I NS only and get 8 - 10 firings (match jacketed loads) before chambering gets too stiff. Then a partial FL sizing in the X-die puts the cases back into NS only mode. With cast bullet loads NS is all that is needed. I have one lot of 100 W-W .308W cases that have been NS'd and fired 32 times with cast loads out of my Palma rifle.

In the last last 48 years shooting numerous .308W rifles and shooting out several barrels I have always NS'd because I learned early on that accuracy is better and case life is longer. Similarly over the years I have NS'd for other cartridges including a lot of various mlsurps. I always NS for the same reasons but mostly for increased case life. Occasionally I have annealed some necks but most often have found that unecessary. I've had 150 Norma 7.62x54R cases I've been using in my Finn M39 the last 30 years. They've been fired I don't know how many times as I stopped tracking after 20 firings. I then, about 8 years ago, partial sized them once and annealed the necks once. In all those years and firings just NSing I've not lost a single case. I still use them to win CBA matches with.

I still use the original LC 79 Match cases I started using in my M70 Match rifle. As they were 1st fired in that rifle they have never been FL sized. I'll be shooting 1000 yards with them (44.5 gr Varget under a 175 gr MK) in that rifle next week. In answer to the OP's question the accuracy is definately better, especially at long range, when NS'd cases are used in my M70 and my Palma rifle. Also accuracy is better in my pressure test rifle with NS'd cases unless really accurate factory match ammunition is used. In my FR8 scout rifle with a 2x7 scope on it it's a toss up because it can't tell the difference with Speer, Hornady or Sierra 150 gr SPs and even cast bullet loads.

There is no true diffinitive answer in general. Your loading technique, chamber and load level will influence the outcome, However, consider if you have 100 brass and fire them 10 times each you will have fired 1000 rounds. With jacketed full throttle loads that is a lot. Try tracking the "times fired" of a box of cases just NS'd vs a box FL sized sometime. You'll be better able to make your own decision for what suits you and your rifle.

[HangFireW8]

The accuracy gains or losses between different sizing strategies depend on only two factors: the resulting run-out, and the resulting variation in boolit pull (neck tension holding boolit in place). If you hold run-out to a minimum and find a suitable neck tension (and don't let it vary), it doesn't matter (accuracy-wise) whether you use a FL or NK die.

[turtlezx]

thanx for all the responses
308 is a heavy barrel savage 110fp
Ihave both neck and fl dies for it
1000lc brass 89 year only fire in 1 gun
sub MOA gun but always looking for better
shooting out to 300yds with sierra 165 game kings
have 168 match sierras to try next

[Larry Gibson]

With that rifle I'd definately NS. If that 89 is ball brass I would also turn the neck just enough so they're just concentric.

[EDG]

For 50 or 60 years neck sizing with bushing dies (usually Wilson) was the bench rest accuracy resizing process.

Now the bench rests folks have mostly switched to FL sizing with a custom FL die that only sizes the case about .001 (yes very little sizing)

I have used both methods a lot. For bench rest type results with a 40X -BR Remington I still neck size only because I can do that with no lube to mess with or clean off of the brass.

For accurate results in run of the mill rifles I use factory FL dies and I set the shoulder to exactly match the chamber using a case comparator made by Stoney Point which is now made by Hornady. The careful sizing of the brass gives excellent results.
If I load ammo for hunting I push the shoulder back .001 with a bolt gun and .002 to .003 for levers, pumps and auto loaders.