Author Topic: Excessive headspace?  (Read 268 times)

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Offline romukom

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Excessive headspace?
« on: August 09, 2018, 08:49:56 AM »
Hello guys,
I am starting to learn to reload 223/5.56 for my Bren.  As I am reading about headspace. I am starting to wonder If I have too much headspace.  I have a hornady headspace comparator.
On a unfired fed lake city cartridge my reading is 1.456"
My fired brass reads 1.469"
So, clearly the brass is stretching close to 0.013"
 Is that excessive?
The once fired brass will not rechamber in my rifle. So I took my full length sizing die and starting gradually resize. And adjusting just to bump the shoulder so it will rechamber. The headspace measurement of the resized brass is 1.462.
FYI, I was working the bolt without the lower receiver and the recoil spring.
Can I reload this brass at least 3 times before I get a head separation?
Thanks!

Offline M1A4ME

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Re: Excessive headspace?
« Reply #1 on: August 09, 2018, 11:13:33 AM »
1.  Back in the early late 70's/early 80's that's how I set my resizing die up for .308 and .30-06.  Just keep slowly turning the resizing die down till the empty case will smoothly chamber, then turn just a little bit more.

2.  I don't throw my brass out till it cracks at the neck.  I know I have more than 3 reloadings on most of it. And when it cracks at the neck it gets shortened/resized/trimmed into .300 Black Out brass.

3. Not sure about your bren but with AR15's, M1A's etc. they recommend you remove the ejector and extractor when using a headspace gauge to check your headspace with the gauges.

4.  I've almost always found the most accurate load to be 100 to 150 fps slower than the max. load - so it's easier on my brass and my guns anyway.  That helps the brass last longer, too.

5.  I you don't bump the shoulder back enough, your loads will produce higher pressures, like shooting factory ammo in a gun with a chamber that isn't long enough.  I've had pressure issues with a couple AR15's in the past.  Very tight (short) chambers.  Sort though my other rifles till I find one that's a little sloppy on headspace, swap out the bolts between the "tight" one and the "loose" one and both rifles are happy and the one that was showing pressure issues becomes normal with those loads.

6.  Bumping it back too much will shorten the life of the brass (won't be able to use it as many times).

Seems like there was something else but it has "left the building" for now.  If I remember it, I'll come back.
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline romukom

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Re: Excessive headspace?
« Reply #2 on: August 09, 2018, 02:27:15 PM »
Thanks for your input.  One thing that I am wondering is that the saami chamber specs are 1.4636 min and 1.4736 max.  Based on the fired formed brass is 1.469"  So that means that my chamber is 5 thousands from the max?  Sorry first time dealing with rifle cartridge.

Offline John A.

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Re: Excessive headspace?
« Reply #3 on: August 09, 2018, 03:28:38 PM »
You don't check headspace with an empty cartridge.  Don't worry about what the brass comes out to.  You should trim it after the first firing anyway.

You check headspace with a go, no go and field gauge and with the extractor removed and you chamber the gauges by hand (not while using the charging handle and the buffer/spring as that could damage the headspace gauge(s).

If it closes on a go gauge, great.

If it doesn't close on a no go, that is ideal, but still not the end of the world.  Especially if it's a well used barrel.  It could still be safe to use even if it closes on a no go.  (My surplus Imbel Fal is this way)

If it closes on a no go, put the field/max gauge in.  It should not close on the field/max gauge at all.  If it does, the chamber is past its' useful service life and should be replaced.

When people ignorant of guns make gun laws, you end up with ignorant gun laws.

Offline CPTKILLER

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Re: Excessive headspace?
« Reply #4 on: August 09, 2018, 09:13:01 PM »
I had that issue to some extent shooting a 7mm International (7mm necked down from 30-30) for metal silohouette shooting with TC Contender.  With that round I had to ream the ID prior loading the first case. 

After that I trimmed the brass fairly often with a Forster Case Trimmer. 

Regarding your situation, simply trim your brass as needed.

https://www.forsterproducts.com/product-category/reloading-case-prep/forster-products-case-conditioning-system/

Offline romukom

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Re: Excessive headspace?
« Reply #5 on: August 09, 2018, 10:37:33 PM »
Thank you again for your comments. Definitely there is a lot to learn. Perhaps I am overreacting.

Offline romukom

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Re: Excessive headspace?
« Reply #6 on: August 10, 2018, 01:39:42 PM »
Just an update. I realized that when full body sizing without bumping the shoulder, the neck stretches. As you guys suggested, to trim the case before trying to chamber it. So, I was able to chamber a fired formed case with 2 thousands of shoulder bump. Thanks for all your help.!

Offline M1A4ME

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Re: Excessive headspace?
« Reply #7 on: August 10, 2018, 03:10:33 PM »
I've read quite a few people agree with RCBS's claim that their X-dies help the brass last longer.  I use them, I don't keep track of how many times I've used my brass, so I can't speak to improved brass life.  Just something to think about.  The X die resizing die is supposed to keep from stretching/pulling the case neck upwards as the expander ball is pulled out of the case.  I use them for .223, .308 and .30-06.
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline romukom

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Re: Excessive headspace?
« Reply #8 on: August 10, 2018, 10:48:50 PM »
Great! I will take a look of these dies.

 

anything