Checking headspace on my first build...

[JeremyM]

Hey 65 Grendeleers..so I’m building my first upper, a 6.5 Grendel, which will be built around the Group Buy 16” barrel and matching GB bolt.

My question is this...since the barrel and bolt were manufactured for each other is it truly necessary to get a headspace gauge and check it?

Thanks

[grayfox]

Lots of guys will do it just to be sure. Since the bolt is cut for the (proper) 0.136 face depth (which you can measure) and the barrel is headspaced on that, you should be good. Check that commercial ammo inserts and falls out of the chamber (like Hdy Black or Custom 123's) - lets you know if the chamber has mistakenly been cut short (some reports altho not on any 16" that I know of).
It doesn't hurt to check head spacing if you have the gauges.

[Growler]

Anyone have a good supplier for a SAAMI spec 6.5 Grendel GO/ NoGO/ Field headspace gauge set? I can’t seem to find a set in stock. I realize a reputable barrel/ bolt combo sold as SAAMI spec and of known vintage (not early) is “probably” ok as received, but I prefer to measure and know. I’ve already become familiar with this process for 5.56 bolts, and have a pretty slick tool to make removing the extractor and ejector a snap.

[Mad Charlie]

Is this a home fabricated tool or ready made?
I don't have much trouble with ext/ej removal/inst. but I am always interested in better/faster ways.

[FRB6.5]

Anyone have a good supplier for a SAMMI spec 6.5 Grendel GO/ NoGO/ Field headspace gauge set? I can’t seem to find a set in stock. I realize a reputable barrel/ bolt combo sold as SAMMI spec and of known vintage (not early) is “probably” ok as received, but I prefer to measure and know. I’ve already become familiar with this process for 5.56 bolts, and have a pretty slick tool to make removing the extractor and ejector a snap.

http://pacifictoolandgauge.com/saami-hea...e-set.html

Cheaper option for one time use, rent them:
https://www.reamerrentals.com/ProductDet...%2E5GB%2Eg

They don't have Field though.

[Growler]

Mad Charlie,

It’s a just a small clamp

https://www.brownells.com/gunsmith-tools...18759.aspx

I’m incredibly adept at launching small parts with springs into dark recesses of my garage. This helps me avoid extra fun searching for them. I think all that’s really required is an empty case and the right punch.

[Growler]

http://pacifictoolandgauge.com/saami-hea...e-set.html

Cheaper option for one time use, rent them:
https://www.reamerrentals.com/ProductDet...%2E5GB%2Eg

They don't have Field though.

Thank you FRB.
Though not my first choice, I may have to rent. That’s better than any option I’ve found yet. If the bolt won’t close on NoGO, I don’t need Field for a single test. The first link was for 6.5 Creedmoore.

PTG has CIP Max/Min gauges for 6.5 Grendel. I’m skeptical about CIP. Does anyone know if that standard is interchangeable with the SAAMI specification regarding headspace tolerances established by the chamber/bolt assembly?

[FRB6.5]

Sorry about that, seems PTG SAAMI Grendel gauges are made to order

http://pacifictoolandgauge.com/saami-cen...results=22

[grayfox]

PTG has a spotty record with the Grendel. In earlier times their reamers were off, IIRC others reporting. Haven't done any Grrr with them myself. I go the Manson or -- there's another mfr -- personally I avoid PTG on this.

[NugginFutz]

^^^ This + 1

Manson is GTG.

PTG = PIA and, in the past, has reportedly delivered non-spec reamers to unsuspecting barrel makers and bragged about it.

[FRB6.5]

Agreed on reamers.