seating depth vs. PSI?

[762willdo]

Can seating depth effect pressure of a given load? for instance say the 30 grains of varget is fine with NO pressure signs when the bullet is seated .020 off the lands but you take that same 30 grains and jam the bullet .020 into the lands will/can it cause pressure signs (flattened primers etc.)
just wondering?

 

[fredhorace77]

yes...very much so

 

[Nomad47]

I like the analogy of a car with its tires against a curb - takes a lot more horsepower if the tires are resting against the curb than if you get a rolling start.

FYI, QuickLoad says to add 7200 PSI to shot start pressure for bullets seated at or in the lands.

 

[alf]

I always start load work in the lands. Then there's only one way to go and eliminates pressure problems.

 

[762willdo]

Great! Thats what i was thinking just did'nt know for sure!

 

[bigedp51]

A perfect example is the .223/5.56 and throat length.

 

[amlevin]

Let's ask this a little differently. Let's say that one has a load that shows no pressure signs at .020 off the lands and then increases this jump. At what point would one start seeing pressure signs with the same load, just the bullet seated farther into the case?

 

[fredhorace77]

Let's ask this a little differently. Let's say that one has a load that shows no pressure signs at .020 off the lands and then increases this jump. At what point would one start seeing pressure signs with the same load, just the bullet seated farther into the case?

at anytime when bullet seating depth is changed the pressure may change also...when it actually happens in a particular load in a given rifle.....Who knows...each gun and load is different...one would just have to try it and see