The receiver OD is the same as that of conventional receivers. The barrel OD for these receivers is, in fact, greater than the OD for conventional receivers. That's why they're called large shank receivers.
The screw placement on target receivers differs from the screw placement on conventional receivers.
You should have good results with your rifle. I have several target receivers - some Palmas, an LRP, some LRPVs and a F/TR - and have been really pleased with them all. And if you don't like the barrel that came on your rifle, you should sell it to me.
Good luck

JS