Home Forums Hunting & Shooting Ask The Gunwriters Neck Length B.S.

So what's the real insiders' scoop on neck length? I hear and read people belly ache about this cartridge and that has too short a neck, and yet two of the "worst offenders" both have stellar reputations for accuracy (300 Win Mag and 223 Rem).

As long as the bullet stays put under recoil, who cares how long the neck is? Given that benchresters have proven that the bare minimum neck tension can produce excellent accuracy, I don't buy the reduced accuracy theory.

Last I checked, bullets weren't falling out of the cases of any 300 Win Mag or 223 that I own or know of.

I would like to see some actual imperical or scientific data that shows that a short neck is detrimental to accuracy or function.

The gauntlet is thrown down to all you naysayers. Feel free to provide anything beyond rhetoric or theory that suggests the inferiority of short necks. Come on, show some sack and back up those claims.

[I would like to see some actual imperical or scientific data that shows that a short neck is detrimental to accuracy or function.

[/quote]

You won't see it, mostly an old wives tale. Although the .223 and the .300 win mag really aren't known for steller accuracy, they do O.K.

After many loads a "donut" forms at the junction of shoulder and neck, creating variable tension unless the bullet does not stick down that far. Also, a short neck can make it harder to get good runout (although this is easy to fix). A short neck means long bullets stick down in the case, which effectively reduces case capacity.

None of these are really problems.

The .223 is, in fact highly accurate. Zediker or Feamster (I forget which) won a bench rest match with an AR15 semi-auto, firing a .2" group with a .223.

The .300 Magnum is slightly less accurate due to the torquing, leaping, blasting which accompanies magnum discharges.

Indy,
Donuts can form in ANY length neck, and I would argue that it is more likely in a longer neck because there is more brass being worked.

I would also argue that longer necks are harder to get straight for two reasons:
1) The longer bearing surface of the longer neck produces more drag over a longer period of time.
2) With a short necked case, the case shoulder will be closer to being in full contact with the die as the neck portion of the case is being sized, less room for error and runout.

If lost powder space causes any measurable drop in performance I would suggest that you are loading WAY too hot to begin with or are using an inappropriate powder.

There is a theory that if the angle of the neck intersects with the throat there will be more erosion. The 243 and 244 are examples.



In the 300 Win the neck is too short to hold some bullet shapes given the short magazine box. This is pointed out in the Nosler handbooks 4&5.



I prefer the look of a longer neck on a cartridge but a shorter neck has a little more powder capacity given the same COL.



The winning bench rest cartridges have long necks. This could be because that's what they use.

Sounds like a good subject for a handloading column. Thanks for the idea!

All the arguments made here so far have merit in some contexts. One that doesn't have much value (unless the caliber is .35 or larger) is that short necks force some bullets to be seated into the powder space. This was viewed as a cardinal sin by many old-time handloaders, but doesn't make much difference at all, as long as the neck hlds the bullet tightly enough. Most bullets don't take up enough powder space to matter.

MD

I've never had a problem with the short necked 300 Savage. In fact, the 300 Sav has consistantly given me better accuracy than either of the 30-06's I've owned.

I would like to have a buck for every time I have heard some behind the counter guy tell me that the .300 Win Mag won't shoot, due to the short neck. I have shot all kinds of them and NEVER had ANY problem with accuracy or bullet slip. CAS, you nailed this one dead on the money. Flinch

If you think that .300 win mags. wont shoot just look at some 1000 yd. Br match results. I have been beaten by them several times. The .300 win mag. is as good as any other .300 given equal rifles and components.

BD

I agree MD. If the bullet is down inside the case, what percentage of the case volume does it take up?.......5%?.......10%? Check out about any reloading manual and in most cases you will find a powder that is within 50 - 100fps of the highest velocity load and has a load density of 85% - 90%.



Ex. from Nosler 5th edition (which lists load density)



300 Win Mag using a 220g Partition



Max Velocity: 2757 fps RL-22

Low Density Load: 2,739 fps IMR 4350 84%





223 Rem with 60g Partition



Max Velocity: 3,219 fps H-4895

Low Density Load: 3,136 fps Benchmark 85%



I realize this isn't a perfect comparison since the cartridges were not tested for max velocity and pressure while the long bullets were seated only to the bottom of the neck.......where you might get 25 - 30 fps additional speed with the slower burning powders. Still seems a valid point.......and here is an example why:



260 Rem with 100g Partition (does not protrude below the neck)



Max Velocity: 3,365 fps H-414 98%

Low Density Load: 3,290 fps IMR-4064 86% (43.0g)



Note that velocity on the low density load (86%) is close to the highest velocity load that almost fills the case (98% load density). Results are similar to the 2 examples listed above. It seems you can get very close to max velocity using a powder with a load density around 85%.

JB,
Given that current production actions have specific limits on how long a cartridge's OAL can be, at some point the only way to make the neck longer is to push back the shoulder. Regardless of bullet diameter, it seems to me that pushing the shoulder back would reduce powder capacity far more than seating a bullet deeper.

One example is the .308 Norma Mag vs. the 300 Win Mag. I've heard Norma proponents claim that theirs is a superior cartridge because the longer neck reduces the bullet's encroachment on powder space. They fail to realize that only reason the neck is longer is because powder capacity was reduced by design (via a shorter case body) to allow for this fact.

I'd love to see an article on the subject. I very much enjoyed your article about handloading myths a while back. Something more along those lines would be added to my valuable article collection that I keep.

When I was shooting a lot of HP silhouette with a .308, the donut was a REAL problem. I don't see how having the bullet pushing past a thickened ring inside the case neck could not be a problem. I remember one lot of Norma .308 brass where the donut formed on the first firing, and it was so thick that you couldn't drop a bullet past the neck of a fired case. Of course it's much less of a problem, if any, if your bullets aren't seated down to the neck juncture where the donut forms. That's where the longer necks have an advantage.

Paul

So far, neither the original post nor the rest of this thread has addressed the real reason for designing cartridges with long necks.

Neck length is more important to the interior ballistics of a cartridge than to its exterior ballistics. The longer neck holds a fully seated bullet tighter and for a longer time than the shorter neck, for more-efficient burning of the powder charge. Neck tension (bullet pull in ballistics lingo) is a vital component of efficient interior ballistics.

Also, there's the matter of what I call socket engagement for better alignment of the bullet. Consider the safe depths to which you must seat a fence post, a telephone pole, and a flag pole, and you'll begin to see the importance of socket engagement. Six inches to a foot may be deep enough to seat a fence post just long enough for you to get out of sight � but it won't be deep enough to keep the post vertical for very long. The longer poles need more "socket engagement" � and so, IMO, do the longer bullets. The more of the pole (or bullet) that's exposed above ground (or the mouth of the case), the deeper that pole (or bullet) must be seated to be held adequately firmly. Seating a longer bullet deeper in a short neck is only a partial "solution."

The original design of the cartridge should provide adequate socket engagement for the lengths of the bullets that the cartridge is designed for. The twelve cartridges in my .220-to-.400 Howell series all have 0.375-inch necks for good socket engagement with heavy bullets, which are all very near the same length in all small-arms calibers. The longer necks align the longer bullets more reliably. Neck length, then, is more of a matter of how the neck length relates to the length of the bullet rather than to its diameter.

The fad and fetish of the highest possible velocity without regard to any other consideration, either interior or exterior, is responsible for both the lighter bullets being favored and the shorter necks that are all that the shorter bullets need, for either adequate socket engagement or adequate containment of the faster powders that the shorter bullets favor.

John

It would be interesting to see a test done......seat a bullet in a case to a certain length with a certain amount of freebore, then seat it out of the case further and throat the barrel that same amount.....I've often wondered what if anything would happen....
Charlie

Eminently logical Dr. Howell. What does logic have to do with rifle loonies? <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

Do you consider Lee Precision's claim that their factory crimp die provides consistent neck tension/bullet pull to have any merit?

BCR

Boggy: Over on AR, Saeed did a test on the very subject you allude to with several calibers and bullet weights. half were crimped the other half not. The crimped bullets were slightly more accurate, which to the {sic} Loonies around here might be important. jorge

On this one, I'm squarely in Mr. Howell's camp. I find it a little frustrating to see people try to argue that because certain techniques work in short range benchrest, those techniques are universally applicable. Seating a bullet with a hand press, with almost no neck tension, into the lands --- I'm not taking that recipe on a pack-in elk hunt!

One thought to add to Mr. Howell's logic is that not only does neck length make a difference, so does brass quality, "state" (that is, annealed or work-hardened), as well as thickness. I've been playing with the WSSM brass, and it is nearly twice as thick in the neck as "normal" brass. It's too early to tell definitely, but I have been able to achieve very robust (uniform over a large range of conditions) results with this configuration.

All that to say that perhaps the longer neck can be replaced, up to a point, by thicker brass. Using Mr. Howell's analogy, it would be like putting the post in concrete. I'm not prepared to argue that this is BETTER than a longer neck, but it is another way to skin that cat, and get more uniform ignition. FWIW, Dutch.

I can see how too short or too long can both have detirmental effects. The old rule of a neck equal to the caliber is probably not too far off. Obviously the 300 win mag and the 300 savage have not been hurt with their short necks. However, I believe the the 7mm wsm sales will be a bit sluggish with the short neck being one of the reasons, the other being the 270 wsm is a better design. also, the required neck for the benchrest shooter and the hunter may differ. the benchrest shooter looking for only accuracy and the hunter looking for reliability. the hunter does not need bullets getting stuck in the lands of the barrel and pulling or moving around in the magazine under the stresses of recoil. when it is all said and done, either the cartridge design works or not. for me, short necks (those with less than one caliber in length) simply look goofy and life is too short to shoot goofy looking cartridges. that's anther reason I am not buying a 25 wssm.

... a minimum, not a universal specification.

To fools, anathema. To thinkers, crucial.