how much does bullet depth matter?

[beex215]

i remember i changed my seating die and to get back to my original setting, i had to mess around seating some more bullets. the ones i did to re adjust i labeled as bad ammo. i went to the range and this bad ammo shot the best for some reason. i dont remember if it was seated deep or shallow. what are the effects of seating deep or not?

[fredj338]

Accuracy wise in a handgun, not much. Pressure wise, it can be dramatic if you are seating deeper. In rifles, the opp is true.

[Zombie Whisperer]

Everyone and everything make a difference, if the pressure signs look good compress the charge a little at a time (.005) until it shoots good again, that is if its not cratering primers or expanding case heads. Always exercise caution with things that go boom.

[Bret4207]

Seating depth can be used to fine tune a load. It can matter a lot or a little or about nothing at all.

[Char-Gar]

It depends.

[cbrick]

Since we don't know what your shooting it's pretty tough to give a specific answer.

When I am fine tuning revolver loads I take the dial calipers to the range with me, load the cylinder and shoot all but the last one. Take it out and measure the over all length, if there is any bullet movement (pulling of the bullet) when shooting long range each shot will go progressively higher.

Consistency of seating depth is important for grouping but again, we don't know what your question is in regards to.

Rick

[beladran]

i once read a artical regarding 38spl with bullseye, i think the charge was 3.2gr with a full wad cutter. If the bullet came unseated and sunk back into the pistol case the pressure went to +p levels.. If the powder compressed 10% it went to 357mag. then they had if you did a double charge.. it was something along the lines of 50,000psi wich is where rifles operate at..

[beex215]

this was in 9mm and 308win

[Char-Gar]

I started handloading in 1958 and have detailed records on every round loaded and that is allot of rounds. If you don't keep good records, then you in up like beex215. You don't know what you did, what you shot, and how to do it again.

Just saying.....

[HARRYMPOPE]

More than on one occasion i have had rifles with cast shoot a bit better (or at least as good) with jump than in the lands.That is if the nose of the bullet is bore riding (or a bit larger) and the velocity isn't something fierce.The 1891 Argentines i have had all shoot very well with almost 1/8" of jump with the Lee 155 Harris bullet!

George

[NHlever]

Since the 9mm is such a small case, seating bullets deeper can raise pressures to dangerous levels. In the .308 the dirrerence is less dramatic,but having the boolit below the neck is to be avoided if possible. There is no reason to expose that bare lead shank to the burning powder gasses. Perhaps it wil do nothing bad for accuracy, but usually it does.

[PackerFan]

I'd stick with the loading manual's recommendation on OAL.

[MtGun44]

The only value to the manual LOA is to estimate if pressures will be lower or higher than
they got when you set the LOA to whatever your gun needs. Manual OAL (LOA) are just
what they used, not some magic number at all.

Seat deeper than they did, you will get higher pressures. Seat longer and you will get
lower pressures. Fit your throat or mag length or whatever suits your needs, just keep
in mind that if you go deeper than the book did, back down the powder charge a bit.

Bill