The concern is neck clearance, not the bore groove depth. Numerous tests have been conducted with oversized jacketed bullets, and as long as the neck was not pinched, the pressure was not measurably different.
Make sure you're sitting down for this: all jacketed bullets are significantly squeezed down even when of the "correct" diameter, by the 0.010" or so deep rifling cutting into the jacket. Another 0.002" is not the difference between safe and kaboom.
But don't believe me. In Volume II, page 76, of his two volume set, Ackley describes the pressure tests he did to dispel the myth of slightly oversized bullets. A standard pressure barrel chambered for 30-06 was tested with a given factory 150 gr load and pressure tested (57,300 psi). The chamber and throat was then opened up to 8mm (.015" oversized) and the standard .308 groove was kept. Bullets were then pulled on the factory ammo and replaced with same weight 8mm bullets. Pressure results were erratic, but averaged 16,000 psi LESS than the standard 30-06 ammo. Furthermore, the velocity dropped over 100 fps. The velocity was then driven up to over 200 fps above the standard 30-06 load with peak pressures remaining less than the the standard 30-06 factory ammo by 4,000 psi.
I am not recommending using slightly oversized bullets, because it could result in a pinched neck, and that will increase pressure, but with sufficient neck clearance, it's simply not an issue, certainly not a mushroom cloud, shrapnel and dead shooter situation.