I’m looking for a bit of advice here please. I have a Savage 12F in 6.5x284 and with a view to shortly swapping barrels I have purchased a Forster GO gauge. This is marked GO - 284 Win, 1.810. – Now the problem is that I have tried it in my rifle and the bolt won’t close on it. I have removed the extractor from the bolt head. It is a new rifle with a factory installed barrel and it shoots and chambers full length sized ammo with no problems.

According to Forsters interchangeability chart this looks like it should be the right gauge.

284 Win 284 Win, 22-284, 6mm-284, 25-284, 6.5-284, 270-284, 30-284, 35-284

Any ideas?