Q. BT/VLD bullet and seating below or above the shoulders.

[308BAR]

For the longer bullets like the 80s Amax/VLD/LRBT or even the 90gn pills in a 223rem. How does seating below or above affect the cartridge accuracy? I understand case volume, preassure and MV is affected but does it affects the bullets/cartridge performance. I been shooting the 80 amax/VLD/BT in what I believe is a standard 223rem chamber. The bullets BT is seated below the shoulder for all these longer bullets even if I jam.

I've been reading a few articles on the Bergers website and German Salazr's blog so I want to get some FTR and precision reloaders/shooters thoughts on this. Trying to decide if optimizing the throating on the 223rem chamber to seat the bullet above the shoulder is a way to squeeze more accuracy out of the barrel and cartridge.

 

[cdn shooter]

You gain a whole bunch of case volume when you throat for the longer bullets. I don't know if accuracy gains are made by doing this but velocity will increase because of the extra powder you can cram in there. You'll want to have it throated so that the end of the BT is in line with the shoulder and the bearing surface starts at the base of the neck if possible.

On another note, it would be nice to see these new short mag type cartridges coming out with longer necks. I have no idea why they insist on barely making the neck one caliber in length. Sure isn't doing the long range crowd any favors, for instance, I think the .284 180 berger has a boat tail length of .2 and change. Where do you put that in a case with a .3 neck!