05-11-2013, 04:28 AM
PTG is the most respected name in gauges, chamber reamers, and precision tools. There is no difference between a 6.5 Grendel or .264 LBC when it comes to go, go-no go and field gauges, other than the name. They are the same because the difference is in the neck not the case body or shoulder. I feel very confident the problem is not with the PTG gauge as manufactured but it is very easy to damage a gauge and take it out of calibration without realizing it. I've seen people drop a .223 go or no-go gauge in a chamber and drop the bolt release. That gauge will be no longer in calibration from even one forceful chambering. These are precision instruments and must be treated with care.
The proper way to use one is to remove the bolt from the carrier, then remove the ejector, and ejector spring from the bolt. Insert the gauge into the bolt face so that it is captured by the rim with the extractor and held in place. Then by hand insert bolt and gauge gently into the chamber and attempt to rotate the bolt closed using finger pressure only. The go gauge should easily rotate into position. The go gauge may rotate into position with some force. That doesn't mean your chamber is to large it just means it is at max specification. Then you move to the field gauge and if it will rotate into position you have an over spec headspace.
I would suspect that if the gunsmith is a competent gun smith and says the gauge is bad, it probably is, but not because it was manufactured that way, because it has been mistreated. I hope this helps understanding this issue.
Bob
The proper way to use one is to remove the bolt from the carrier, then remove the ejector, and ejector spring from the bolt. Insert the gauge into the bolt face so that it is captured by the rim with the extractor and held in place. Then by hand insert bolt and gauge gently into the chamber and attempt to rotate the bolt closed using finger pressure only. The go gauge should easily rotate into position. The go gauge may rotate into position with some force. That doesn't mean your chamber is to large it just means it is at max specification. Then you move to the field gauge and if it will rotate into position you have an over spec headspace.
I would suspect that if the gunsmith is a competent gun smith and says the gauge is bad, it probably is, but not because it was manufactured that way, because it has been mistreated. I hope this helps understanding this issue.
Bob