Velocity node question?

[Homerange]

Can someone translate to farm boy speak?

Mistakes abound where grams are mentioned as grains. g or gr ...don't get them mixed up !

 

[Intheshop]

Can someone translate to farm boy speak?

Calculation of tractor fuel cost,based on say the number of corn rows planted in two different shaped fields.

What concerned me more was,I did understand it(sorta).... having not made it very far in school.

 

[D-4297]

Looks like @RegionRat and a few others confirmed what I was finding , chrono-wise . That changing seating depth has a minimal effect on velocity , and shouldn't take a load out of node , unless your load was on the edge to begin with . Velocity variations appear to be about half node changes .

 

[dellet]

Looks like @RegionRat and a few others confirmed what I was finding , chrono-wise . That changing seating depth has a minimal effect on velocity , and shouldn't take a load out of node , unless your load was on the edge to begin with . Velocity variations appear to be about half node changes .

Depends on the cartridge, better said case volume, and or powder used.

Changing case volume, by moving the bullet in or out, changes the burn rate of the powder and/or starting pressure. If you are using something Quickload, this is where adjusting the powder table for actual velocity would come into play. So .010" movement in a 22 Hornet would have a much greater effect than a 338 Lapua.

If you fool with it enough you generally find a ratio such as .010" of bullet movement equals .10 grain of powder on the chronograph.

Internally, seating deeper creates a higher peak pressure, lower muzzle pressure and more completely burned powder. Less muzzle blast arguably less felt recoil.

These slight adjustments can change primer ignition to bullet exit time, while maintaining the same velocity, or the opposite.

Where this plays out more visibly than the target, is a gas operated system, even more if you shoot subsonic, because you end up restricted to a pre existing velocity window.

You can have a load that functions, but has a wide ES/SD and matching vertical spreads or shoot bug holes and be forced into manual cycling. Seating depth can effect burn rate that much in the right conditions.

The whole idea of an optimum charge weight is staying away from those extremes.

It might be a minimal effect on velocity, but it could be a very important effect.