300 Win Mag Headspace

[bigedp51]

Really a funny face answer, go to Cast Boolits or a Enfield forum and say what you said here and watch how fast your are laughed out of the forum.

"If you don't go there I can't help you."

 

[J E Custom]

 

[CatShooter]

cutting the chamber to the belt will not matter because the datum measurement to the shoulder is .014 short on ADG Brass and is no way to adjust that by cutting to the belt measurement there will still be .014 case stretch. that is about normal with all belted cases that measured. I fire form mine with light load and jammed bullet to help with the problem

The belted case cannot stretch 0.014", because the belt limits the forward case movement on the first firing, to whatever the belt headspace is - typically, a few thou.

I have a fine .264 WM, and the factory cases are 0.039" shorter at the shoulder line than the chamber is - upon firing the shoulder blows forward 39 thou and the cases are fine (and do not stretch).
The dies are set to leave a slight crush on closing and the cases do not stretch.

The belt is only used for headspace on the first (new case) firing, after that, you treat all belted cases with a shoulder, like you would a stand bottleneck case.

 

[trhall]

Hi, I am going to make a headspace gauge for 300 Win Mag, but I do not want to make it to SAAMI specs (.220"). Does anyone have some ADG 300 Win Mag brass on hand that they can take an average measurement on 5-10 pieces of brass from the base to the front of the belt? Would be very much appreciated.

Regards,
Dae

You can get a great headspace gauge from Larry Willis that enable you to set headspace exactly to your specific chamber.

http://www.larrywillis.com/

 

[bigedp51]

CatShooter

He didn't mean the case will stretch .014 to reach the bolt face. He meant the case shoulder was .014 short of touching the chambers shoulder and stretched forward.

Example below of a new rimmed .303 British case in a Willson case gauge and its short shoulder location.

And now a fired case in the Wilson gauge, the amount the case is sticking above the gauge is where the chambers shoulder actually is. Again rimmed and belted cases date from the late 1800s when the forward part of the case was not critical.

Below a brand new Remington .303 British with a short shoulder location on the left. And on the far right the effects of full length resizing with .009 head clearance and a case fired three times.

I know the post is about a belted case but I do not have any belted case photos, but the rimmed and belted cases have the same basic problem. They both need to headspace off the shoulder and not the rim or belt to prevent case stretch.

Nice to hear from you again CatShooter you old (expletive deleted)

 

[CatShooter]

CatShooter

He didn't mean the case will stretch .014 to reach the bolt face. He meant the case shoulder was .014 short of touching the chambers shoulder and stretched forward.

Nice to hear from you again CatShooter you old (expletive deleted)

Edwardus Maximus...

Cases can not stretch forward. They "blow out" to fill the chamber - there are many wildcats that move the shoulder far forward from the factory position. Typifical of these are the Gibbs wild cat cartridges, and several modern cartriidges based on the 6mmBR with the shoulder blown forwards.

Back in the spring of 2013, I received a new Rem 40-XB/SS .220 Swift that had been on order since the first coming...

... but by then, the country was in a buying frenzy of all shooting stuff because of the Dec 2012 Sandy Hook school shooting, and there was no .220 brass to be found anywhere, and guys were selling fired cases for $4 each on gunbroker

So I was whining and sniveling on a shooting site about my sad state of affairs, and one of the members offered me 100 pieces of brand new Norma .220 Swift cases that someone had tried to convert to .220 Wilson Arrow, but he didn't know what he was doing and badly dented the shoulders with too much oil.
Since they were free, I took them.

The cases would not chamber because they had flared out at the shoulder from pushing the shoulder back... plus they now had a measured 0.095 to 0.105" (a 1/10 of an inch!!) of excess headspace in a standard Swift chamber.

Very Badd Juju.

So, first, I annealed all the cases, neck and shoulders. Then I bought a .220 Swift Full Length sizing die (GASP), and then slowly brought the die down on a case until the case would barely chamber with a fair amount of force on the bolt.

Then I sized all 100 cases for a tight fit, and then I sold the die.

Then I loaded 10 of the cases loaded with a 95% charge of 4064 and 55gr Speer "TNT's".
Before firing, the loaded rounds were rolled on a lube pad soaking wet with G-96 oil.
All 10 rounds fired perfectly, and did not stretch, not even 0.001", and formed perfectly.

The shoulders were blown forwards.

On the left is a crumpled case, and on the right is a crumpled case that was fireformed and then reloaded.

All the cases were now loaded with the same combination, and formed at the expense of fuzzy little woodchucks.

 

[bigedp51]

Edwardus Maximus...
Cases can not stretch forward. They "blow out" to fill the chamber

You are correct and my mistake in words, my two dyslexic typing fingers did not get enough coffee this morning.

Now old buddy, why don't you blow it out your (expletive deleted) you commie pinko pervert.

Below a "Blow Out" from putting Titegroup powder and Remington 7 1/2 primers in the cattle feed.

 

[CatShooter]

CatShooter

Again rimmed and belted cases date from the late 1800s when the forward part of the case was not critical.

Nice to hear from you again CatShooter you old (expletive deleted)

First belted cartridge was 1912, (375 H&H) and it was designed for the new fangled "Magazine Rifles" that Holland & Holland started making, cuz the flanged Nitro Express cases made for double rifles, would not feed reliably in Magazine rifles, and considering their use, that was a really badd problem.

The forward to shoulder "headspace" on belted cartridges is STILL not critical... my 264 WM shoulders blow 0.039" (39 thou) forward on the first firing, but the belt headspace is 0.004" (4 thou). I neck size them and they last forever.

 

[bigedp51]

First belted cartridge was 1912, (375 H&H) and it was designed for the new fangled "Magazine Rifles" that Holland & Holland started making, cuz the flanged Nitro Express cases made for double rifles, would not feed reliably in Magazine rifles, and considering their use, that was a really badd problem.

The forward to shoulder "headspace" on belted cartridges is STILL not critical... my 264 WM shoulders blow 0.039" (39 thou) forward on the first firing, but the belt headspace is 0.004" (4 thou). I neck size them and they last forever.

Actually the belted case was invented in 1910 so I only fibbed 10 years, which is nothing in the span of cordite history.

So you tell us forward of the belt is not critical, and you have .004 head clearance on the first firing. Then you neck size and let the case headspace on its "non-critical" shoulder.

But you left out the part about lubing your cases on the first firing to keep the case from stretching.

So basically you were "stretching" your post a little also old buddy. Let me know if your nose grew a little on this one.

Note to other readers, CatShooter and I our old buddies who like to rib each other. And CatShooter is older and has more reloading experience. But I makeup for this minor age thing because I'm younger and much better looking.

 

[CatShooter]

Actually the belted case was invented in 1910 so I only fibbed 10 years, which is nothing in the span of cordite history.

Meadow Mufffins...

https://en.wikipedia.org/wiki/Holland_&_Holland

 

[CatShooter]

Actually the belted case was invented in 1910 so I only fibbed 10 years, which is nothing in the span of cordite history.

So you tell us forward of the belt is not critical, and you have .004 head clearance on the first firing. Then you neck size and let the case headspace on its "non-critical" shoulder.

But you left out the part about lubing your cases on the first firing to keep the case from stretching.

So basically you were "stretching" your post a little also old buddy. Let me know if your nose grew a little on this one.


Note to other readers, CatShooter and I our old buddies who like to rib each other. And CatShooter is older and has more reloading experience. But I makeup for this minor age thing because I'm younger and much better looking.

Nose is the same....

I did not lube these cases, cuz I was in Texas, shooting yotes and feral dogs on a Kobe cattle ranch at the time of first firing, and did not have all my range kit with me.

They stretched ~4 thou and did not stretch again.

 

[CatShooter]

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