300 Win Mag Headspace Gauge

[pavementends]

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.

Peterson makes "long" brass for 300 win and 7mm Rem brass which if I understand it is longer from the base to the shoulder to avoid the excessive case stretch on the first firing common to belted cases. I see you have identified the issue as the chamber being a bit undersized in front of the belt.
I normally just use a go gauge and then add tape to the base (measuring with a comparator) to get a no-go. Not clear on how one would use a no-go only.

 

[Rflshootr]

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.

I'm curious about a few things. Do you know the neck diameter of your loaded rounds and the diameter of a fired round? Also, if you wouldn't mind me asking, what state are you in?

 

[DoneNOut]

Peterson makes "long" brass for 300 win and 7mm Rem brass which if I understand it is longer from the base to the shoulder to avoid the excessive case stretch on the first firing common to belted cases. I see you have identified the issue as the chamber being a bit undersized in front of the belt.

I'll buy that long brass if the SAAMI reamer is able to true some dimensions.

I normally just use a go gauge and then add tape to the base (measuring with a comparator) to get a no-go. Not clear on how one would use a no-go only.

I spun the action onto the barrel until the bolt on a No-go would tightly close. I discussed this with Forster and they did verify this was a technique in sorting things out. Give that same no-go .003 more and I am into the Field gauge length. I don't righty understand how the belt specs can have a "Field gauge" considering these just fit the belt in the chamber and it's not based on the shoulder...

 

[DoneNOut]

I'm curious about a few things. Do you know the neck diameter of your loaded rounds and the diameter of a fired round? Also, if you wouldn't mind me asking, what state are you in?

Loaded bullet .331. Fired .339. 8 thou seems to be a lot compared to my other 30 cal stuff.

 

[bamban]

That's about right for the fired round. The SAAMI neck is just 0.3407 at the end. The brass just have thinner walls, compared to 308 Win, for example.