300 Win Mag Headspace Gauge

[DoneNOut]

Yes or no. Don't want to know the why, just the how.

Savage barrel nut barrel 300 WM.

Barrel in barrel vise
Insert go gauge under extractor of closed bolt
Spin the action on until bolt opens and closes freely?

Done this with a bunch of non belted cartridges and all is grand. Just checking. Research on the topic goes into crap shows about the topic.

 

[entoptics]

That's how I've done it on 4 belted mag barrels, though I add a piece of painters tape (0.004") to the base of the gauge as a "no-go". Clock the barrel so it opens/closes freely on go, absolutely won't close on the tape+go. I also removed the ejector to avoid any issues of alignment, and to make it easier to manipulate the gauge without it popping out.

Base to shoulder on two different X-caliber barrels (264 Win Mag and 7 Rem Mag) was identical using this procedure.

 

[DoneNOut]

That's how I've done it on 4 belted mag barrels, though I add a piece of painters tape (0.004") to the base of the gauge as a "no-go". Clock the barrel so it opens/closes freely on go, absolutely won't close on the tape+go. I also removed the ejector to avoid any issues of alignment, and to make it easier to manipulate the gauge without it popping out.

Base to shoulder on two different X-caliber barrels (264 Win Mag and 7 Rem Mag) was identical using this procedure.

Yah't see the gunboard drama on this! Lol! Thanks!

 

[tobnpr]

Set your headspace off the belted gage for fireforming initially (or perpetually, if you don't handload and will be shooting only factory ammo). If you handload , set your shoulder bump/headspace off the shoulder datum with a comparator like any non-belted cartridge after fireforming.

 

[DoneNOut]

The Forster GO gauge broke, before that it wasn't working too great. Would sometimes go, sometimes not at same setting. So, I resorted to just using the NO-GO and the fired shoulder length is same as the other two factory built rigs.

 

[Revolting Peasant]

I plan to do a belted magnum in the near future. Already have a Bighorn Origin LA sitting in the safe. Was planning on doing exactly what you posted in #1, trying to set it for a minimum chamber headspace. Will be my first belted magnum. Let me know if you learn anything different.

 

[Revolting Peasant]

My first belted magnum build…

 

[DoneNOut]

I plan to do a belted magnum in the near future. Already have a Bighorn Origin LA sitting in the safe. Was planning on doing exactly what you posted in #1, trying to set it for a minimum chamber headspace. Will be my first belted magnum. Let me know if you learn anything different.

I'm done with this Savage factory take-off. Bolt seizes on fired case every daggum time. Must use mallet to open bolt. No excessive pressure signs though...

New factory PPU brass with shoulders that run 2.255" out the box.
The following fire formed shoulder lengths no joy too:

2.273
2.272
2.271

SAAMI shows 2.270 shoulder length. My other two 300WM fire to 2.271 and 2.273.

I think I will get a Bart CF barrel in 300 PRC and go from there...Lapua makes the brass for PRC.

 

[Muddyboots]

Yes or no. Don't want to know the why, just the how.

Savage barrel nut barrel 300 WM.

Barrel in barrel vise
Insert go gauge under extractor of closed bolt
Spin the action on until bolt opens and closes freely?

Done this with a bunch of non belted cartridges and all is grand. Just checking. Research on the topic goes into crap shows about the topic.

Might be just me, BUT I always removed the extractor when setting headspace which is how I read in gauge instructions plus in discussions with some top gunsmiths. The bolt should be floppy free so zero pressure is added to headspace gauge. Also how I doublecheck sized brass to be perfect to rifle headspace. Takes minimal time on Savage, Rem etc to remove.

 

[DoneNOut]

Might be just me, BUT I always removed the extractor when setting headspace which is how I read in gauge instructions plus in discussions with some top gunsmiths. The bolt should be floppy free so zero pressure is added to headspace gauge. Also how I doublecheck sized brass to be perfect to rifle headspace. Takes minimal time on Savage, Rem etc to remove.
View attachment 471353

Welp, I removed the ejector and slid the gauge under the extractor. If I also remove the extractor, does one just bump the gauge out with a cleaning rod from the muzzle?

So these aren't extractor grooves?

 

[bamban]

Not MB, I just grab it with a magnet

 

[DoneNOut]

Not MB, I just grab it with a magnet

Can you reference the above picture please?

 

[P7M13]

I put my action in the vice because if you aren't anchoring the action, cocking can change the headspace by turning the action. This is less of an issue on well timed actions
Never tried this with only a no-go. How did you break the go gauge?
I use an aluminum rod to knock out the gauge.

 

[bamban]

Can you reference the above picture please?

I was responding on how to remove the gauge if you were to remove the extractor as well.

Never seen those particular gauges, but yes, those are extractor grooves