223 Case Rupture - Headspace Discrepancy?

Yes! Gas regulator. Anybody that has owned an MAS 49/56 that was "Kind of" converted by Centry Arms to .308 knows exactly what we are talking about.
 
Cryogenic,
I usually work towards a 'Lazy' full stroke of the bolt/carrier,
A gas restrictive block only limits the velocity the gas hits the bolt/carrier,
Tube length and powder burn rate determine the duration of the pulse.

Guys with very short barrels often used a longer gas tube coiled around the barrel to regulate pulse, and it worked pretty well,
But coiling that brittle stainless steel tube was a bunch of fun,
Ruined more than a few before I figured out how to do it...

The issue I have with most 'Aftermarket' gas blocks is they are made of high carbon steel, which doesn't hold up well to powder flame/temp erosion and dirty powder gives you something else with small passages/parts to clean...

I don't have all the answers, just been doing this long enough to form coherent questions...
 
I wouldn't use range findings on a bet. The only used brass that I would ever think about using would be commercial once fired from a good source.
Click to expand...

Actually, I kind of like 'range findings'. I have a huge supply of LC brass I've picked up over the last few years at the range. Shooters leave it behind all the time because it has crimped primer pockets. That tells me that it's only been shot once and I get to process it for the first time.

I've paid for my Dillon Super Swage many times over and other than spare time I have absolutely Zero Dollars invested in my brass supply for my AR's.

Now if it doesn't have the original crimp intact, it just sits there with all the other crap brass that's left behind.

My bolt action gets a gourmet diet though. Nothing but Lapua Match and I buy that new.

On the original topic, when reloading people need to learn the benefit of a good case gauge or headspace measuring tool (tool, not gauge) when setting up their sizing die. Just cranking it down according to the included instructions will often lead to exactly the same type of separated cases shown. WHERE the break occurs is determined by what part of the case sticks in the chamber and what part moves when fired. Where the two parts meet is where the break occurs.
 
I should have explained -the early tests by HK found indeed the case was torn in half !! :eek: Thats why the ,looking at a fired case , you see the marks of the grooves now cut in the neck and shoulder !! There are stains also from the escaping gas .This reduces the neck's grip on the chamber . You will find grooves even on a 9mm case from the P7 . The marks of the grooves are more coloring from the gas rather than grooves matching the chamber grooves.Yes I love my P7 !! :D
 
The flutes in chamber are for such purpose. Spaniard greased their cartridges in their early versions of cetme. But It could still happen if the rollers are under-sized. With proper sized rollers, indicated by proper bolt gap, the brass can last as long as other actions.

-TL
 
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