I think a lot depends on the bullet profile. I've had no problems feeding from the mag with my .243 T3. That's using 75 gr V-Max and 90 gr Accubonds. I seat .020 off the lands, the rifle shoots well at that depth.
ELD or VLD for example may be a problem due to length from tip to ogive.
One semi-solution is to load for two OAL measurements, assuming of course the longer rounds shoot better. You single load the first (longer) round in the chamber, then load the mag with shorter rounds for follow up shots if needed. Mark the longer "single shot" rounds with a Sharpie to identify them.
I'm assuming this is for hunting use?
If it's range use, then loading single rounds is your obvious work around.
To actually answer your question, like the guys said this isn't unusual to find your max possible OAL (just touching the lands) is longer than called for. I'd be surprised if it wasn't, since the rifle is designed to safely chamber any SAAMI spec'd cartridge.
When Hornady, as an example, lists the OAL for a loaded round using one of their bullets, they use the maximum dimension that should fit in any rifle that meets SAAMI specs, without jamming the bullet into the rifling. I don't know how much distance to the lands they use for a standard dimension, but I expect it's substantial for liability reasons.
