Deep Bullet Seating

[targettarget]

Gentlemen,

Question regarding the depth of a bullet inside the casing.

Will the depth of a seated bullet affect the pressure generated assuming all factors are equal....Powder, primer, casing strength....

Suppose you have a 9mm round that is seated to "factory specifications". I realize that the amount of powder added is in direct reflection of how much pressure is generated, but what about if the bullet is seated deep into the casing with a normal amount of powder?

 

[sdeering]

Yes it will. Not in a good way, if you are too deep.
Stephen

 

[CyaN1de]

It can also be bad the other way as well. Seating a rifle bullet into the lands of the rifle will create higher pressures as the bullet does not have the "running start" at the lands, the pressure has to build in order to get the bullet on it's way down the barrel.

 

[colinjw]

Seating the bullet deeper reduces the amount of space available in the case.
When the powder ignites it creates the same amount of burning gases but in a smaller space. Therefore up goes the pressure.

I saw an example of this a couple of years ago with someone new to reloading.
He was reloading 40's and switched to a different head. However he forgot to adjust the seating die accordingly and the heads went in too far.
He got off one shot & the Glock suffered some serious damage along with his face and hands.