My apologies in advance if this topic has already been beaten to death...but...

As a 20+year hunter, I've recently taken up the hobby of reloading (and am enjoying it very much). I have a novice inquiry. Can anyone offer an opinion on the acceptable tollerance (in +/- thousandths of an inch) for bullet seating? Is there a predictable outcome for too deep vs. too shallow?

Thanks in advance.

Goodoz,

The COL tolerance depends on several considerations.

1) Type of action ( semi, bolt or single shot )
2) Length of magazine ( semi, bolt )
3) Freebore ( chamber pressure )
4) Troath ( accuracy in general terms )
5) Bullet's design specs

As an example, it's customary that Barnes recommends to seat the bullets to be 0.050" off the lands, in order to achieve good accuracy.

In other cases, the COL dictated by reloading manuals, simply are not feasible for some actions.

On the other hand, please beware of COL before and after firing...with heavy recoling cartridges, that can seat-down a bullet further into the case.

Best regards, Gus

Thanks Gus...my dilemma deals with more toward the inaccuracy of +/- .0025" (measuring with a high quality digital caliper). My press (Rock Chucker) seems to vary in that range even when the die is locked down tight. I'm reloading a spectrum of cartridges from 338WM down to .22-250...all bolt. The discrepancy, in any case, has not caused any issues within the action of any of my rifles. My concern is safety (for my toys...and for my face!!). I suppose I'm probably just a little nervous as a new reloader, eh? Also, I'm not sure what the manufacturer's tollerances are for bullet construction (Hornady VMAX in this case).

Thanks, Jeff

Most if not all hunting bullets vary in position of the ogive (shoulder) slightly so measuring 'tip to base' OAL only really confirms that they'll fit your magazine.

The more important measurement is to the shoulder of the bullet - it is this that first contacts the rifling. Comparators (Stoney Point is one I use) clip on the calipers thus allowing shoulder to base length to be checked.
Checking a dozen bullets straight from the box should confirm that +/- .0025 is not unusual.

As in a lot of things, ymmv, but IF OAL is as recommended in the manuals (safe, if a bit short) AND they chamber easily and shoot OK,
all should be well.

Benchresters and others, I hear, can and do trim
the tip to achieve exact same length. Lots of fun :-)

It's been discussed before, but the thumbnail version is this:
When they make a bullet, the base to ogive distance is held fairly consistant, however the ogive to tip distance is allowed to "run wild". Most rifle dies use a diameter on the ogive as the contact point (otherwise they'd mash the tips) and again allow the tip distance to "run wild". What your seeing is the stackup variance in the "run wild" portion of the bullet (die contact point to tip).
As your just starting out, and staying within the books paramiters, you can safely allow yourself a +/- .0150 (.030 TIR) window) on the OAL.

Want some fun? Measure the OAL variance on a couple boxes of factory ammo.