PSA Bolts out of spec?

[stonehog]

I have a 20" PSA upper that has always been a bit sketchy, but was my first Grendel. Since I got this I've added a 12" Odin and 18" Faxon. I now have bolts from:
PSA
Odin
Monster (2)

After some strange results with a go/no-go gauge I started wondering about the spec of these bolts so I ordered a depth gauge to check the bolt faces. I found:
1. Odin = .136"
2. PSA = .133"
3. Monster 1 = .136"
4. Monster 2 = .1365"

I'm calling all of these OK except for the PSA bolt. Anyone else found this on their PSA bolts?