Plunging neckline with GC cast bullets (GC below neck?)

[ohland]

After personal experience with 285129 boolits in my 7-30, my mind is somewhat open to the idea of a GC below the neck in a bottleneck case. Not my cup of tea, but 20 285129 boolits left nothing in the barrel but powder residue, just like the 285448.

Memories of the RCBS 357-180-SIL warm my heart, with the wide band just above the GC. The 285129 also has a relatively wide band above the GC. However, not everyone has access to the older boolits where they used the wide bands to try and deal with high pressure loads....

I am curious (blue) whether the Louverin multiple bands are sufficient to handle the Unique loads in the 6.8mm Remington SPC. I will eventually cast up some of the 280468 (L) boolits and load them in the SPC. The S and L versions differ in one drive band, otherwise they are the same (plus weight, of course).

Methinks the low (relative) pressures and good loob should be enough to keep things under control. Only thing that annoys me with the deep seat is the lower groove loob is exposed to the powder in the case. Ever pull a boolit and see the powder stuck to it?

:veryconfu

[BruceB]

The issue of lubricant being exposed to powder in the case is easily handled by placing just a MINISCULE amount of dacron under the bullet. Problem solved; the powder cannot contact the bullet.

I've created many various load recipes that ended up with the gas check below the neck.... or even below the shoulder. This has never given rise to any problems that I'm aware of, even here in the desert heat of Nevada. Once upon a time, it may have given me some concerns, but experience has put any such worries to rest.... I don't even consider it, as a general rule.

Good lubricant that won't melt and contaminate the powder is a very pious thought in our heat.

[35remington]

I suspect that that same small amount of Dacron mitigates some of the gas cutting issues as well. Proper bullet hardness and modest pressures so as to cause less deformation of the bottom if the bullet might also pay dividends.