Proper Neck Length

02 March 2002, 05:44

Snapper

Proper Neck Length

When designing a new cartridge, what should the neck length be? I know that many feel it should be at least one caliber and some say a min of .300. Consider the 500 Jeffery and the 505 Gibbs. One may be to short and the other to long, but both work well. Would .450 be to short to grip a .510 bullet properly? Thanks for the help.

GJS

02 March 2002, 06:13

470 Mbogo

[QUOTE]Originally posted by Snapper:
Hi Snapper,
The 500 A-Square has a neck length of .400 and so does my 470 Mbogo and I've never heard of any problems. The biggest problem I found with .475 bullets is that there is a variance in the manufacturers sizing. Some are .474 some are.473 and some are .4725. Make sure that your sizer ball on your dies allow for this. I have two sizer balls for my full length sizer and with Woodleigh bullets I size the cases once and then remove the ball and tighten the neck down again. The Woodleighs are the only ones I've had to do this with. End result is I don't think you need a full caliber neck but it is a good rule of thumb. Just make sure you get good neck tension.

470 Mbogo

02 March 2002, 12:11

Snapper

470 Mbogo:
Thanks for the reply. Even at 400, there is a lot of metal around your .475 bullet.

02 March 2002, 14:03

Paul H

quote:
Originally posted by Snapper:
When designing a new cartridge, what should the neck length be? I know that many feel it should be at least one caliber and some say a min of .300. Consider the 500 Jeffery and the 505 Gibbs. One may be to short and the other to long, but both work well. Would .450 be to short to grip a .510 bullet properly? Thanks for the help.
Are you considering shooting cast bullets? If so, I'd look at the longest cast bullet you would want to shoot, and design a neck that would allow the bullet base to be flush with the base of the neck.
On the 500 Jeffrey, I have to crimp the 450 gr cast bullets into one of the lube grooves, though that is OK, as the COL is tollerable. I'll be making my magazene longer then a std Jeffrey to allow use of 570 gr bullets, but will likely be limited on how big of a cast bullet I can use.
My main thought on necks is, I'd rather have one .1" longer than .1" shorter then ideal. Longer necks allow one more flexibility in bullet selection and seating, and the added case capacity for a short neck case really isn't that big of a deal, IMHO.
GJS

02 March 2002, 15:32

470 Mbogo

[QUOTE]Originally posted by Paul H:
Hi Paul,
All of my cast bullets are actually shorter than the copper lead bullets.My .510/ 615 grain lead cast spire point is the same length as the 600 grain round nose Hawk. The .475 round nose cast is shorter than the round nose Woodleigh or Swift. The .510 cast bullets have gas checks while the .475's are paper patched. Seated to the proper OAL the .510 cast bullets protrude 3/4 of the gas check depth past the base of the neck and the .475 cast bullets are shy of the base of the neck. Do you have your 500 yet and would you like some of the .510/615 grain cast bullets to try out? If you would send me an e-mail.

470 Mbogo