charged case is now ready to have a bullet seated into the case
mouth. Assuming that the cases have been properly expanded and/or
chamfered, bullet seating presents few potential problems. Placing
the bullets base squarely in the case mouth, guide the bullet
into the die body as far as possible to ensure that it does not
tip. Ideally, the bullet base should seat snugly in the case mouth,
holding itself in alignment. In raising the ram slowly, you will
feel the bullet contact the seater plug. Continue raising the ram
to fully seat the bullet into the case.
depth for a particular cartridge is determined by a number of factors.
In the reloading data section, you will find the seating depth we
used for a given bullet in the cartridge in question. Please understand
that in most instances this length is only a guide, and that your
seating depth may be different.
is especially true if you are loading for maximum accuracy, and
need to adjust the seating depth to match the throat of your particular
rifle. This is fine, but bear in mind that deeper seating reduces
the capacity of the case, which in turn raises pressures. Going
the other way, seating a bullet out to the point that it actually
jams into the rifling will also raise pressures. If you vary the
seating depth from the length listed in the manual,
the charge weights will need to be adjusted accordingly.
A bullet is seated into our primed and charged case. We now
have a loaded cartridge!
Davidson Seating Depth Checker. Also known as comparators, these
devices allow the handloader to check the critical relationship
of bullet ogive to rifling for a loaded cartridge. This relationship
is actually much more important to accuracy than the OAL figure
which is more commonly used.
seating depth for many firearms is
determined by the action type, and may not be varied much without
causing functioning problems. Autoloading pistols, for example,
will be limited to a set maximum length by the magazine. If the
rounds are loaded to an OAL that is too short, the pistol may not
feed or function reliably. Cartridges that require a crimp, either
rifle or handgun, are also limited to a very specific seating depth
by cannelure placement on the bullet. Revolvers are a good example
of this. Their bullets must be seated to the cannelure so they may
properly receive the roll crimp
they need to prevent them from being pulled under recoil.