[MikeG]

It is true brass flowing is a clear indication of excess pressure; however, by the time you get that far you are WAY into the red zone. You have problems that should have been detected earlier with the micrometer, chronograph, or just plain common sense.

If you get that far, stop, be thankful that you aren't picking pieces of the gun out of your teeth, and figure out what went wrong!

 

[MikeG]

Rick,

I would have to disagree. I have read several articles in the past couple of years, by Jaimison in Shooting Times and Barsness in Rifle/Handloader, where they had either strain gages or professional labs test their handloads. Handloads that 'appeared' perfectly safe by traditional measures, proved in the neighborhood of 70,000 PSI, if I recall correctly.

If anyone is interested I'll try to find the magazine articles. Remember - that's no brass flowing, no cratered/pierced/blown primers, nothing out of the ordinary. So what pressure would they have to have to see brass move into the ejector cut in those examples?

It's entirely possible to have things like a sloppy chamber or too-soft lot of brass leave those signs, before you hit those sorts of pressures. In a modern bolt-action rifle, I agree, 65,000psi isn't going to blow it up unless there is some other defect. But.... I don't belive that it is a safe thing to say that you are for sure under 65,000 or even 70,000psi, just because the brass hasn't flowed.

And then there is the entire question of action type. With a bolt gun, they're pretty strong, but if you get brass flowing in a 94 Win, say your prayers......

Respectfully -

 

[MikeG]

Ray, very interesting, Ken Waters has preached the gospel of measuring the pressure ring for many years. Now it looks like we have some additional research in that area.

One thing to consider in all of this debate is why we'd like the brass case to contain the powder gas. The obvious answer is so that the bullet gets propelled out of the end of the barrel, and the shooter doesn't get a face full of soot.

But it goes beyond that. Once upon a time, case failures were considered a routine thing, and guns were designed to handle the escaping gas at 50,000CUP or whatever pressure. Look that the 98 Mauser - the big shield on the back end of the bolt, for example. We know that if a case fails at 50,000CUP it shouldn't blow the rifle to bits.

Now some folks will look at the strength of the modern bolt action, and say, Hey, this thing can take XX,XXXXCUP more pressure so let's load it up. All is well and good till a case lets go. But did the pressure blow up the barrel - usually not. Often the bolt lugs are still intact. Yet the escaping powder gas split the action into pieces. That part of the action wasn't capable of handling powder gasses blowing back through it at ultra-high pressures, even though the rifle might have not shown any problems if the case did not rupture.

Take a careful look at pictures of rifle blowups and see what parts of the gun survived and what did not. It's obvious the damage that the escaping gas did, once you think about it. The rifle design could not handle a case failure at that pressure level.

The cautious reloader/wildcatter keeps their fingers intact!

Rick, didn't mean to pick on you or your response, hope you didn't take it that way. There are a lot of people reading these forums, from those who have never loaded a single round of ammo to those who have been in the industry for many years. So the policy of the forum is to always encourage safe reloading practices. Sometimes it means shooting down some old wive's tales that have continued through the years, but that's a good thing in that we have an opportunity to spread knowledge. So I'm genuinely glad you brought up the topic of brass deformation.