Some pump rifles are extremely sensitive to ammunition OAL, which should be shorter than 3.340" on your 30.06. Maybe your longer loads were for a single-shot? If they are .200" (2/10ths) longer I wouldn't expect them to properly fit the magazine either. Does it operate okay with new, in spec rounds? If so I'd just stick to those. Is it not ejecting, not unlocking, or not extracting? Does it close hard? The unlocking bar, have you checked it for burrs or bending? Also some rifles were shipped with long term preservative everywhere, and it can get so hard recesses it will cause problems, even on brand new guns. Its also hard to see and remove, try a dental pic in all the traveling ways. Any of these things can be exaggerated by longer ammo. Jarret