VLD vs. Hybrid pressure ?

[idaho1]

All things being equal besides the bullet, which bullet would be expected to have a greater pressure , the VLD or Hybrid???
6mm 105 gr 6XC
VLD bearing surface .389 OAL 1.230
Hybrid bearing surface .366 OAL 1.292

Norma brass-new
39.6 gr H4350
COL 2.745
cci200

In a recent range session, the VLD showed zero pressure signs and the hybrid was showing cratered primers and slight brass flow.
I would have thought that the Hybrid with a smaller bearing surface would be lower pressure. Would its longer length add pressure by filling the case more?

 

[sandwarrior]

All things being equal besides the bullet, which bullet would be expected to have a greater pressure , the VLD or Hybrid???
6mm 105 gr 6XC
VLD bearing surface .389 OAL 1.230
Hybrid bearing surface .366 OAL 1.292

Norma brass-new
39.6 gr H4350
COL 2.745
cci200

In a recent range session, the VLD showed zero pressure signs and the hybrid was showing cratered primers and slight brass flow.
I would have thought that the Hybrid with a smaller bearing surface would be lower pressure. Would its longer length add pressure by filling the case more?

In short, probably. Also, the hybrid is going to have the ogive seated just a little closer to the lands. Those two circumstances combined with the fact the 6XC is an improved type case and isn't showing just how hot it is yet, could be why you are just starting to see signs with the Hybrid and not the standard VLD.

However, that doesn't really matter. You should work each bullet up to where it shoots best from your rifle. There is enough design difference between the two that it would completely make sense they start showing pressure signs differently. And, you also come up with a different accuracy node.

 

[idaho1]

In short, probably. Also, the hybrid is going to have the ogive seated just a little closer to the lands. Those two circumstances combined with the fact the 6XC is an improved type case and isn't showing just how hot it is yet, could be why you are just starting to see signs with the Hybrid and not the standard VLD.

However, that doesn't really matter. You should work each bullet up to where it shoots best from your rifle. There is enough design difference between the two that it would completely make sense they start showing pressure signs differently. And, you also come up with a different accuracy node.

Thanks Sandwarrior,
I admit, I was taking shortcuts. I finally got my hands on some hybrids and loaded them to the same specs as the vld load I had " worked up" properly. I was surprised to see the pressure signs but I shouldn't be.....

 

[sandwarrior]

Cool, glad that helped. What part of North Idaho are you in? Where do you shoot at?