bullet seating depth quesiton

[joseph-98]

i was wondering today,
when you loading different length bullets ,say, mag length vs to the lands if you were to load the same amount of powder would the speeds out the barrel be that big a difference ?

 

[Dogtown]

It's all about pressure and seating deeper into the case creates more pressure. Jamming into the lands also creates more pressure, in the form of a potentially dangerous spike. Seating further out tends to leave room for more powder and the closer the bullet ogive is to the lands sometimes is better at guiding the bullet into the bore. However, this isn't always the case as some bullets in some rifles like to "jump" into the bore vs being guided.

The takeaway from all of this is that seating depth adjustments can affect pressure which in turn will affect velocity. Load up a batch of ammo with wildly different seating depths and test them at distance (>200m) and you'll see what I'm talking about.

 

[MitchAlsup]

Speed would not change all that much,
Barrel harmonics could change drastically.