Full length resizing verses neck sizing

DON

Handloader
Dec 3, 2013
459
15
Is any there any benefit to just neck resizing, speaking only of my 30-06 brass?
Is there any accuracy node that neck sizing gives verses full length resizing?

Thanks,
Don
 
In theory, neck sizing extends brass life and improves accuracy in that less energy is expended expanding the brass to chamber dimensions. In the field, the advantages may, or may not, be realized.
 
DON":vxqbz313 said:
Is any there any benefit to just neck resizing, speaking only of my 30-06 brass?
Is there any accuracy node that neck sizing gives verses full length resizing?

Thanks,
Don
Not to offend anyone, but why would you want to achieve the best accuracy at the bench? If it doesn't translate in the field? That whole mind-set always baffles me. If I can squeeze all the accuracy I can out of a rifle, that means in the field I know I have a premier performer and that I know where it's going to impact on game when I do my part. If it's off a little and you throw it into the real world hunting situations then your just hoping you make a clean shot... that makes no sense.

As for the OP. Yes neck sizing has a lot of benefits. One is brass life, the main advantages are neck tension and lining the bullet up to YOUR barrels axis.

First, neck tension. If you have a custom gun this comes into play more, you can match your die to your reamer that was used on your barrel. You can also on a factory gun , play with the neck tension to squeeze better accuracy out of it. Hence the Redding type- S dies and their bushings for example or Whidden Gunworks.

Second, once fired brass had expanded against the walls of YOUR guns chamber. Thus giving you the exact dimensions of your chamber and all the data of case capacity, of you measure it, and how much you should bump the shoulders back, .002" for hunting applications, in case dirty or sand gets on the bullet. What this does is line the bullet up, when you throw in a neck sized, reloaded round in your rifle, with your barrels axis. Which in return helps when you fire your rifle the bullet hits the lands straight and doesn't have as much off axis impact. This can cause poor accuracy results, think of the bullet slightly off to the left, the lands then smash the left side of the bullet. It leaves the barrel and it wobbles. Throw a football with a weight on one side, or a flat side, how does it spin? Effects accuracy, you bet!

So to avoid your bullets being lopsided, you neck size your brass so the bullets match and line up in your chamber.

Full length sizing dies bring the brass to SAAMI specs, which is designed to allow, for example a .308, to chamber in every .308 made! Think of all the different .308 guns in the world and know that not everyone measures the same. Of course they are reamed to a .308, but their tolerances are not the same. So SAAMI spec was invented in part to keep ammo consistent and safe for us to shoot. That's the tip of the ice berg.

PM me if you want more info, I have some good reads on reloading and measuring your brass , why you should do it.

Now on a Semiautomatic, you FULL Length Resize! Those chambers are sloppy! This will guarantee the bolt lines up and engages the lugs properly and will ensure that you seat your ammo correctly.

My wife thinks I only have 3 guns
 
Very well written WaveSlayer.

I do believe that neck sizing does improve case life and improves accuracy, worked for me. If a case or two is hard to chamber after a few firings, then I'll full size the batch of fired brass and bump back .002 and after firing I'll use the neck sizers again.
 
Waveslayer - I think what Dr Mike was saying about it not necessarily translating in the field - is that at "normal" hunting ranges & shot opportunities, it probably doesn't matter at all if the rifle & load is capable of ultimate accuracy.

For instance, I had seconds to get on my mule deer buck this year at 140 yards. I dropped to prone and shot him. Worked out just fine. Speed and getting on target was far more important than if my rifle shot 1/4" groups, 1/2" groups or 1" groups.. A match grade rifle & ammo wouldn't have produced any better results, nor would it have given me any more confidence. I knew I was going to hit that buck as soon as the crosshairs settled on his chest.

Don - I do neck size, using very nice Wilson dies and a small RW Hart arbor press, for three of my rifles, from which I want best accuracy:

.308 Win with Krieger barrel - a varmint weight rig I've used in competition. Neck sizing and the nice dies allowed me to come up to the "next level" of accuracy in prone competition. This rifle, with the nice chamber & barrel, did well with regular factory match ammo, and better with my neck-sized ammo.

.204 Ruger varmint rifle - now and again I'll go after rock chucks or the tiny sage rats. I wanted all the accuracy I could get. I've never tried conventional dies with this rifle. The Wilson neck-sizing dies are working great.

.25-06 Rem 700 - my general purpose coyote, pronghorn & mule deer rifle. I don't know that the neck sizing dies really did much for me with this one. Accuracy is good with standard dies, or with the neck-sizing dies.

Two things have popped out at me over the years:
1. Neck sizing works for a while, then sometimes the cases have to be full-length sized to smoothly chamber.
2. Neck sizing is NOT necessary for excellent accuracy.

On that - several of my competition shooting friends use their Dillon progressive machines and full-length dies, to produce competitive, even match-winning ammunition. I had to stick that in my pipe and smoke it for a while as I had assumed that my neck sized brass & slow loading process was going to produce superior ammo. Hmmm. Not what I'm seeing - 'cause these guys are shooting just as well or better than I manage.

So - I'd say -it's worth a try. I like it. It doesn't work the brass hard. In fact with my Wilson dies, there is no expander ball at all. Just squeeze the neck down a bit, and that's it. Very nice. It's a quiet, nice kind of loading, and it does produce good ammo.

Is it worth the investment in the new dies? Only you will be able to answer that.

Regards, Guy
 
Guy-

I would disagree, we are splitting hairs on accuracy and precision. Guns can be accurate and guys can make accurate shots like you did on your Mule deer. Good Shooting by the way. Precision is important to make accurate shots.

If my gun is not capable of holding a consistent cold bore shot, then how much does that effect the accuracy at 500, 600, plus yards? It could mean a miss. If you can eliminate all the negative effects that are effecting accuracy and precision., why not do it? So neck sizing can eliminate some of the factors going into poor accuracy. Hopefully this is making sense and I'm not as confused as I seem to be. Basically if your gun produces sub part groups, it's not accurate, if it's not accurate it can't be percise

I have a stock Remington 700 that I full length size on my Dillon 650, I hand load the powder, and it holds a sub .5" MOA all day long with 3 different loads I have for it. Especially the gold standard using FGMM.

My wife thinks I only have 3 guns
 
Years ago they had the same argument over at a website called snipers hide. The guys who were neck sizing said they were getting the best bang for the buck. One of the really accomplished Shooters over there called BS and pulled out his old FL dies and took his favorite load and punched out a bunch of ammo trying to be pretty much as careless as possible. Then he proceeded to post Group after Group which was 3 inches at 500 yards.
Granted the guy shoots a high-quality gun and is very accomplished. Actually most benchrest Shooters now are full-length sizing their brass.... but they do it with dies that minimally size.
I recently had a brass extraction problem on my 3006 after neck sizing 3 times with moderate loads. After taking a bunch of measurements Above the Rim of the case where I felt it was sticking I found that virgin Brass is about .005 under my chamber dimension. I found my Hornady FL dies keep the brass about .003 under chamber dimensions. But with spring back I found that my lee fl and my redding body die along with brass spring back have the dimension at less than .001! So you might be surprised at how close tolerance you still get with FL dies. All this said my favorite die combos for a lot of cartridges is the Lee collet die in conjunction with a redding body die.
But... it is my humble opinion that 98% of the accuracy of your gun will come from how much it likes the Load ...the bullet... the powder ....the whole combination and the way your Barrel vibrates on bullet exit. Unless you're dies are horribly set up I think there will be virtually no change in accuracy between die types if you have a great load.
 
Most bench shooters are using tighter chambers, hence the lack of having to full length size them, they don't grow much. But you are true, if we stuck with a factory gun, which most guys on here are using then there will always be a debate.

My wife thinks I only have 3 guns
 
I found a load last year with Nosler virgin brass for my 3006.
I full length sized them and produced the same accuracy.

Ray.
 
I use bushing FL dies and adjust them to to the head space on a rifle so the bolt has a very slight drag closing the bolt. I don't use the expander button and pick the size bushing for the neck tension needed to hold the bullet. The die is set up for one rifle only. Brass has a long life.
Billy
 
Billyram":3viee7rb said:
I use bushing FL dies and adjust them to to the head space on a rifle so the bolt has a very slight drag closing the bolt. I don't use the expander button and pick the size bushing for the neck tension needed to hold the bullet. The die is set up for one rifle only. Brass has a long life.
Billy

Nice. Great way to combine neck & full length sizing. I'd imagine the accuracy is very good.

Guy
 
Here's a factory AR15 with reloads with full length resizing die at 100 yards.
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Here's using the neck sizing die on my 6.5 SAUM at a Mile, first shot was high so I adjusted.
1ef9b9bbd74ad0833950051ec16916e0.jpg



Here's full length resizing on my Warbird at 200 yards
3d4bab422bf699729f160cb2097acbf9.jpg


And for just fun a fly at 108 yards. With a stock R700 using full length resizing bumping the shoulder back .002"
2ea1ed3a96ef94045ad674f9fbd867ef.jpg


My wife thinks I only have 3 guns
 
I do have a few Redding Type S full sizing dies with the bushing, just adjust them to .001 bump back. They also work great.
 
Guy Miner":28olehjw said:
Billyram":28olehjw said:
I use bushing FL dies and adjust them to to the head space on a rifle so the bolt has a very slight drag closing the bolt. I don't use the expander button and pick the size bushing for the neck tension needed to hold the bullet. The die is set up for one rifle only. Brass has a long life.
Billy

Nice. Great way to combine neck & full length sizing. I'd imagine the accuracy is very good.

Guy
I don't have to worry about the cases getting tight and having to bump the shoulder back. The accuracy is good with zero head space holding the case centered in the chamber.
Billy
 
Thanks for all the comments. I have a set of 30-06 RCBS dies that have FL & Neck sizing dies in the set.
I'm thinking of getting a Forrester Bench rest die set. It seems to me it's a better quality die set compared to RCBS.

Don
 
Great posts.
You guys can shoot too!
Waveslayer the fly cracked me up. Sounds like something I'd try. Impressive shot.

OP, another huge factor is caring for your brass. One of the things I've found that makes a difference is annealing. Brass gets brittle with repeated firings and annealing helps.
I doubt if this is relevant in your particular situation but be careful on what neck tension you use if you jam bullets. If you use a couple thousandths and jam AND have to remove an unfired cartridge the bullet can stick in the barrel and cause a powder mess. :grin:
 
A couple of years ago I did some accuracy testing with my Marlin 336 in 35 Rem. I realize it's not the most accurate rifle in the world, but it still worked well enough for the test.

In this test I tried full length sizing, neck sizing, and a few other factors to see what would affect accuracy the most. What I found is that the method of sizing didn't make much of a difference, but the resulting neck runout of the brass made a noticeable difference. Since then I have sorted all of my 35 Rem brass not only by manufacturer but also by neck runout. If they're not extremely straight (<.001), I don't use them. FYI, most recommend <.002, but I have enough 35 Rem brass that I only use the best ones.

To consistently get the best runout I have found that the Lee collet die does the best job. Yes, that means mostly neck sizing, but I combine this in many cartridges with a body sizing die in order to have the brass just fit the rifle's chamber. If you can get low runout with full length sizing, then go for it. I'm just letting everyone know what I found in my own testing and what I've done to try and keep results consistent.
 
I strive for pretty straight ammo and usually shoot for .003 or under. not all guns seem to be terribly affected by run out. Years ago my buddy bought 2 boxes of federal match grade 308 to shoot in his new Savage Le rifle. We were pretty shocked to find one third of the two boxes of ammo were over 006 runnout...some as high as. 011! We sorted those two boxes into three batches of ammo one batch had virtually no run out... one had run off from .004 to .006 ....and the rest was over .006.
The bottom line was at our farthest distance on our range which is 330 yards all the ammo pretty much went into a two and a half inch group. These guns do have surprisingly tight Chambers for a factory rifle but of course the bore is typical Savage ...rougher than a cob!
 
Note that I was talking brass runout, not ammo runout. I don't recall that I measured that in my 35 Rem testing, believe it or not.

I've noted it here before, but the best factory ammo runout I've ever seen is with Nosler ammo. I've seen some factory ammo with runout just as bad as you mention shoot extremely well, though. Why? I don't know, and I just try to do as best I can when loading my own.
 
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