No-Go Gauge Went on Proof Impact Precision 737R Prefit.

[Nimrodmar10]

Today I changed out a barrel on a Impact Precision 737R with a new Proof Stainless 6 GT barrel. After torqueing the barrel to the action to 75 ft. lbs. I put a
Manson Go gauge in the chamber and closed the bolt. No problem. I then put the No-Go gauge in and the bolt closed easily. Problem! I put a .0015" piece of Scotch tape on the back of the No-Go gauge and the bolt would not close. I didn't force it, but there was resistance on the bolt handle. I then took the Go gauge and put 2 layers of Scotch tape (.003") on it. The bolt closed easily. When I added a third layer of Scotch tape (.0045") the bolt again would not close. I'm taking this to mean that I have approximately .004" of excess headspace.
I'm new to swapping prefit shouldered barrels. My question is, is this a problem?
I have not fired the barrel yet, but am thinking about it. I can call the gunshop where I purchased the barrel, but since it's Saturday, I guessing I won't be able to call Proof until Monday. What should I do, shoot it or return it?
TIA
Nimrodmar10

 

[Joel Russo]

Years ago when Proof Research started doing pre fit barrels for our Terminus actions, we had customers encounter the same issue.
In corresponding with Proof, they offered this explanation, which has proven to be true.
Many of our customers report back with extremely accurate barrels.