Neck length vs. bore Diameter

[1shot]

If you were designing a cartridge for 1K prone competitions, what is your opinion of neck length vs bore diameter? I understand that this is caliber specific, i.e. the 222 and a very long neck and the 6.5x284 with a short neck. For the sake of conversation, this cartridge has a .473 bolt face and will be 7mm in caliber. The capacity should be in the neighborhood of 73 gr.+ of H2O. Shoulder angle will probably be 30 deg.
Thanks in advance for any input,
Lloyd

 

[Steve Blair]

Most cartridges have approximately one caliber neck length. If designing a new cartridge, I would go a little longer. In the 7mm case, maybe around .300-.320".

 

[mikecr]

You could use a 75% flamepoint standard for neck length:
Here min neck length = ((NckID/2)/(TAN(Shldr*PI()/180)))/0.75
So
ID = .286 (expanded)
Shoulder = 30
Neck length = .330"

.330-.284 = .046" out of neck-shldr junction with one cal of bearing seating.
You don't want bearing in a donut.

No matter what you choose, it'll shoot. This flamepoint approach is to help with barrel life and cartridge efficiency. Standard WSSM ratios provide other design efficiencies.

 

[Rtheurer]

Hmmmm? Lets see ....the 280 AI
Has a 473 case head... Yes
Has 73+ gr of capacity... Yes
Has a .345 neck length... Yes
Has a Shoulder angle of 30 or more... Yes
Has Dies available....Yes
Hmmmmmm??

Its cool to make something new but Im pretty sure this cartridge fits every thing your looking for in a long range rifle.

Yours in marksmanship.
RussT

 

[FroggyOne2]

But Russ,

What if he wants a short fat cartriage?

Randy

 

[MrMajestic]

But Russ,

What if he wants a short fat cartriage?

Randy

I know a couple of women that fit these requirements! :

 

[Rtheurer]

There in lies the answer "WANTS" I can almost garrantee that what ever comes of it has been already done.
He can however call it the 7mm Super Lloyd...

If I ever get my butt going on my 280AI prone gun Ill challange him to a heads up match at 1000 yards.

Hope all is well
RussT

 

[1shot]

Ahhh Russ,
Always the comodian!
Lloyd

 

[FroggyOne2]

Well that will be possible when we meet at Perry, ummm everyday there.