"Case neck is less than one caliber"

[Rusticlease Shackiforous]

Hey guys. Just spending my new years celebration time thinking of guns I want, and loads to go with them. I was reading the Hornady manual (#9) and under .300 win mag they say, "The only problem, if it is a problem, is the neck is less than 1 caliber in length.". Now I'm wondering what issues are associated with a case neck length that is shorter than the bore dimension...

 

[4thPointOfContact]

It doesn't resist side forces to the bullet as well as a cartridge with a longer length case neck, is the only one I can think of. That may possibly lead so some accuracy problems from a bullet not pointed quite straight down the bore.

 

[Grumulkin]

Another potential issue would be insufficient neck tension to keep the bullet from moving under recoil.

Actually, in the case of the 300 Winchester Magnum, with a chamber and throat that are correctly aligned I don't think either side forces or neck tension are realistic issues. That cartridge is capable of excellent accuracy.

 

[Walkalong]

"The only problem, if it is a problem, is the neck is less than 1 caliber in length."

That's an old guideline for seating bullets..."make sure it is seated at least one calibers worth in the neck".... or in other words, .308 into the neck for a 30 caliber bullet. It's for good neck tension.

It's a nice guideline, but isn't written in stone.

 

[Bart B.]

If one looks at all the bullets with cannelures for crimping case mouths into, many violate that mythical axiom being less than one caliber forward of its heel. Just another myth that's dispelled by so many examples such as the cartridge in question mentioned in this thread and lots of other cartridges.

"Horse feathers!" or "Bah humbug!" are responses by believers who insist it be law and common sense reasoning by their standards and comprehension of reversed reality.

In contrast, if one uses the original "caliber" dimension standard of 1/100 inch, well, you can imagine how little grip the case neck would have on bullets.

 

[Bart B.]

It doesn't resist side forces to the bullet as well as a cartridge with a longer length case neck, is the only one I can think of. That may possibly lead so some accuracy problems from a bullet not pointed quite straight down the bore.

30 caliber bullets can be a couple thousandths off center in the chamber and crooked 2 degrees off the case/chamber axis and still shoot 1/2 MOA downrange; 600 yards, for example. New cases are often such that this happens. Matters only to those who think it's a problem. The angle and length of the chamber leade at the origin of the rifling is such that it straightens up all our shortcommings in perfection. Lesser angles are better than greater ones.

 

[stoky]

Some (Ken Waters et.al.) say the base of the bullet extending past the neck into the power space is bad ju-ju.
Others say that the lack of a "quench zone" lends itself to accelerated barrel throat wear. There's an pretty erudite article about this on the Long Range Hunting forum by M.L. McPherson and others. It was purportedly one of the considerations in the design of the 6.5 CM.

 

[stringnut]

Case neck is less than one caliber blah , blah, blah. Leads to all kinds of issues, blah, blah , blah. Bullet may intrude into powder space, blah, blah, blah. Simple sloutions for all the supposed horrofic things it supposedly causes. Make sure the ogive of the bullet is outside of the case neck by bullet choice and seating depth. Also make sure your expander ball is of the correct diameter . You can always sand it down a bit for more neck tension. The bullet intruding into the powder space also is a non issue. If it bothers you use a flat base. If you want to use a boat tail or long monolithic bullet it doesn't make much difference. By the 4 to 1 rule of powder difference in the same case even if you take 5% of the available powder room it is only going to lower your velocity 1.25 %. The extra throat wear is real. However, it only makes a 5-10% difference in barrel life. If you can afford to wear out a barel you can afford a replacement. My experiance is with the 300 Savage and friends that have 300 Winchesters and a couple of 284 derived wildcats. None of us has ever had any short neck issues.