- Location
- Steel Town and The Peg
Happy with shipping time indeed.
Where to find, or borrow, a go / no go gauge for 7x57? and PTG rant thread
- Thread starter The Kurgan
- Start date
- Location
- Steel Town and The Peg
Well, I got around to testing the PT&G go / no-go gauges today on my new-to-me and mint Brno 21H. Very nicely machined gauges and fast shipping ! No complaints whatsoever. However, my factory bolt swallows the no-go gauge. Wondering if I should have purchased a field gauge! What is interesting is that my spare M98 bolt with zero visual wear and no lug set-back also swallows the no-go gauge. Hmmmmm. WTF?
- Location
- Steel Town and The Peg
Yes, everything is clean and the bolt closes without any pressure
- Location
- Western Manitoba
To follow up Evanguy's suggestion, I had bought a cheap set of feeler gauges (Canadian Tire? Home Hardware?) and cut a number of circles just smaller than the gauges - lets you find headspace "exactly", if that is what you are after.
Edit: Okay, apparently I'm now officially an "old guy" - just repeated what I posted in #5...
Edit: Okay, apparently I'm now officially an "old guy" - just repeated what I posted in #5...
Last edited:
- Location
- Steel Town and The Peg
It won't close on one layer of standard black electrical tape
- Location
- Steel Town and The Peg
Found this, made me chuckle:
"GO and NO-GO gauges are used in factories, or when rechambering or installing a barrel. They are "factory specs." Any significant use or wear will result in the bolt closing on a NO-GO gauge.
There is no problem unless the rifle closes on a FIELD REJECT gauge, which indicates the rifle has or is close to excess headspace.
Let me draw a comparison. You buy a set of new tires. You know the factory tread depth spec is .33-.35".
So when the tread wears down to .32", you buy new tires because they are no longer factory spec. Of course, you don't get much wear out of the tires, which are still almost new, and you spend a lot of money. The wear ridges in the tire are the "Field gauge" for tires; tires are OK until they reach that point"
"GO and NO-GO gauges are used in factories, or when rechambering or installing a barrel. They are "factory specs." Any significant use or wear will result in the bolt closing on a NO-GO gauge.
There is no problem unless the rifle closes on a FIELD REJECT gauge, which indicates the rifle has or is close to excess headspace.
Let me draw a comparison. You buy a set of new tires. You know the factory tread depth spec is .33-.35".
So when the tread wears down to .32", you buy new tires because they are no longer factory spec. Of course, you don't get much wear out of the tires, which are still almost new, and you spend a lot of money. The wear ridges in the tire are the "Field gauge" for tires; tires are OK until they reach that point"
- Location
- Western Manitoba
No idea what a BRNO was chambered at. You can find SAAMI chamber dimensions in ANSI/SAAMI Z299.4 – 2015. Maybe newer version of that standard available. But ANSI is an American Standard, so no idea what standard BRNO was using. Note especially where the headspace is measured from - a "theoretical" .375" circle part way along the shoulder slope - not from point of shoulder, start of neck or any other "physical" point to measure from.
