Question about long action receiver dimensions

I haven't been able to find the answer to this question after lots of searching, but...

Are there any external dimension differences between a large shank and small shank receivers? Or, in other words; do large shank receivers have a fatter outside diameter versus a small shank receiver? I ask because I ordered a McMillan stock for a long action, but I want to make sure the inletting is the proper diameter. Not like it matters, though, since it will be bedded.

Tony.

Both are exactly the same other than the barrel shank threads.

Thank you!

Tony.