Neck Length - Can you make it too long?

[TScull]

I'm having a reamer made for me for a 7mm short magnum cartridge. The intent is for long distance (600 to 1000 yard) use with Berger's 180 gr VLD bullets. The starting cartridge is the 300 WSM. The design of my case body is short enough that I can get a 0.45 inch long neck if I want. That is 1.58 caliber diameters.

Is there a down side to this length? Will the bullet gripping force start be to become too inconsistant after a certain length?

 

[JerrySharrett]

If you are limited by the length of the parent brass you plan to use, I'd bet on better accuracy being with longer neck (shorter body). For more velocity, the shorter neck (longer body as in the Ackley Improved series).

 

[Pete Wass]

I have been wondering

of late if there is an optimum case neck length for a given case size. I have been making some new 30-44 cases from 6.5x47 cases and there is a goodly amount of neck that could be used if it would be beneficial. The Aardvark case came to mind. I wondered if the inherent accuracy of that case is from it's long neck or other factors. I though it to be a shame to waste a great neck if it could be an advantage.

 

[J. Pendergraft]

A consideration with long necks is how consistent can you make the brass. Long necks can have advantages but I would not consider long necks to contribute to a more accurate cartridge. There is a wildcat round with an extremely short neck (I don't remember the details) that shot just as good as any other benchrest cartridge. There seems to be no consensus on how important the runout of the bullet to case body is but I feel better with a low number for runout. Long necks can potentially cause more bullet runout. Long necks are good for chamber throats so barrel life is likely to be better.