Muzzle velocity and temp powder

[postal]

If thats true it sucks, as that severely limits your powder charge ability.

For a 308, depending on powder, most loads are full or compressed.

There's room for the powder. But when playing with jamming, you need to back off the powder charge so you dont get a dangerous pressure spike.

The real problem is magazines that will hold these LONG rounds... Hence, most of these people run AICS mags that allow a longer COAL.... and an aftermarket barrel with a tight chamber since factory barrels tend to be long in the throat.

And, to be honest, I forgot if the actual jammed bullets were berger VLD, or Lapua Scenar.... but it's one of those 2 that shoot better jammed into the lands. In retrospect, I think its the scenar....

But, as I said... never played with them- dont see the point of that hassle.

[milotrain]

It's common to jam Berger VLDs, but they also work in jump. You really have to work their seating depth either way though. I think the myth that they have to be jammed is based on the fact that it's a lot easier than doing all the load dev to find out where they want to be jumped in your rifle.

I don't love VLDs, especially with Hybrids, and A-Max bullets which are way more flexible without much BC loss. Everyone I know who runs jammed are single loading in some sort of long range match. It's a last .0001% sort of shooting that makes me think such loading is worth it, unless it's to make an old torn up millsurp rifle perform better, which I've not had to do but heard about it.

[kcstott]

Thats what I mean with the pressure spike. When we were doing our mile shot with a 300 win mag and 220 gr SMK I was seeing the primer just start to crater and flatten out with the bullet just off the lands. I backed the bullet off the lands even further and the pressure signs never went away but never got worse.

ended up using just over starting load and .030" off the lands. that seemed to print nice little groups