Pressure: when is too much and why?

[Lawnboi]

If I torch the brass firing a wet round I’m not as concerned as if I had a catastrophic failure, primer leakage/case head separation ect. I don’t mind tossing some wrecked brass. I don’t need an etched bolt face, wrecked firing pin, extractor or ejector.

I don’t know how or why moisture causes pressure but it definitely does.

Field conditions dictate I load my rounds to reasonable pressure. How much is too much can only be figured out in a pressure test barrel I’d guess. Brass and barrels are so different. But if you’re seeing ejector shine, some stiff bolt lift/ minor pressure signs on your case you’re asking for trouble.

 

[Pharmseller]

Absolutely. Generally, I try to remove it right before a shot.

No need. Escaping gas blows the tape off.




P

 

[35WhelenAI]

Personally, I've been part of no other forum that has more loads over velocity (more than a little over) openly talked about for any specific cartridge. Seems to be the way to strut some stuff, IMO. Some are sure they know better than 100 years of sound reloading practice. It's been said in this thread, get a bigger case. Forget running a little four-cylinder at red line and get some cubic inches and less comparing of pubic inches.

 

[Tell]

Personally, I've been part of no other forum that has more loads over velocity (more than a little over) openly talked about for any specific cartridge. Seems to be the way to strut some stuff, IMO. Some are sure they know better than 100 years of sound reloading practice. It's been said in this thread, get a bigger case. Forget running a little four-cylinder at red line and get some cubic inches and less comparing of pubic inches.

I’ve seen a lot of it on all forums. It’s like the three shot group club. You shoot 10 groups that are all over the place, but one of them has all three bullets touching and it gets posted on the interwebs as a one hole gun if I do my part.

I’ve even thought it to myself when shooting with the chrono. I see the highest number and think to myself, this load shoots that, not the average. It’s stupid, but we want it to be true.

I’d just like to point out that the topic was how you know when you’re over pressure, what the signs are, what happens in what order, and what are the dangers of each. I’m here to learn and I want to understand the topic. Try not to read into it “this guy wants to run hot and we better caution him against it.” I want to know things like why case head separation happens, and why someone like Ryan Avery asks in the most recent shoot to hunt podcast “well how much were they bumping their shoulder” when ADG brought that up.

Will bumping the shoulder more than a couple thousands every time make case head separation more likely?

 

[Shortschaf]

Will bumping the shoulder more than a couple thousands every time make case head separation more likely?

The farther your brass has the grow, and the hotter the loads are inside it, the more likely that CHS is to occur

 

[JGRaider]

I’ve seen a lot of it on all forums. It’s like the three shot group club. You shoot 10 groups that are all over the place, but one of them has all three bullets touching and it gets posted on the interwebs as a one hole gun if I do my part.

If you've seen it a lot you're bound to be able to post a link or two for some examples?

 

[Tell]

If you've seen it a lot you're bound to be able to post a link or two for some examples?

I think this is going in a fruitless direction.

 

[Tell]

The farther your brass has the grow, and the hotter the loads are inside it, the more likely that CHS is to occur

Is there any way to tell that a CHS is on the way? Let’s say you have 12 firings at a moderate load on Lapua brass but you’ve been bumping 6 thousandths every time. Is there some sort of sign that one is coming soon?

 

[Bluefish]

Is there any way to tell that a CHS is on the way? Let’s say you have 12 firings at a moderate load on Lapua brass but you’ve been bumping 6 thousandths every time. Is there some sort of sign that one is coming soon?

You can check the brass for stretch/thinning with a L shaped pick. Run it up the inside of the case and if you can feel a valley/ridge forming at the case head, you are getting close.

 

[TaperPin]

Is there any way to tell that a CHS is on the way? Let’s say you have 12 firings at a moderate load on Lapua brass but you’ve been bumping 6 thousandths every time. Is there some sort of sign that one is coming soon?

Here’s what is happening on the inside, and the faintly visible ring on the outside is a tell tail sign the inside is quite thin. As others said, the best thing to do is feel the inside of the case with an “L” shaped pick.

This thinning happens even if neck sized only, but is sped up with excessive headspace from over sizing.

 

[Shortschaf]

Is there any way to tell that a CHS is on the way?

Agree with the above two posts.
Ill put this source here because it looks complete. Lots of seperate threads and info out there for CHS signs

A subtle sign of risk of case head separation

I had a case head separation occur several months ago even though I routinely look for signs of excessive pressure on each case during each reloading. The cases in question had been reloaded 5-6 times. After the case head separation occurred in the one case, I looked much closer at the...

forum.accurateshooter.com

 

[JGRaider]

I think this is going in a fruitless direction.

Because you can't back up what you say. That's a problem for you.

 

[wind gypsy]

Because you can't back up what you say. That's a problem for you.

You're really trying to argue that people sharing cherry picked 3 round groups on the internet isn't a common occurrence, often with the "If I do my part" bit thrown in? Get the fugg outta here with that nonsense.

 

[JGRaider]

You're really trying to argue that people sharing cherry picked 3 round groups on the internet isn't a common occurrence, often with the "If I do my part" bit thrown in? Get the fugg outta here with that nonsense.

So post up a link or two then and back it up. Should be easy if it's as common as you guys say. I'm more amused with the necessity of a 30 shot group myself.

 

[wind gypsy]

So post up a link or two then and back it up. Should be easy if it's as common as you guys say. I'm more amused with the necessity of a 30 shot group myself.

He didn't say a thing about a 30 shot group, just that people cherry pick 3 shot groups to share. You chose to imply further and bring up a topic of past butthurtness.

Post 2788 is one i came across in the last day. An example of a guy saying he's just waiting to shoot a one hole 3 shot group he can cherry pick it and share.

Tac Ops Rifles

KM-OPS on the Fed Ex truck to Seattle Washington to a true Tac Ops Ninja 🥷 Mike R.

www.snipershide.com

 

[JGRaider]

I didn't say he did bring up the ridiculous 30 shot group idea. Nice try on the link though....the guy was obviously making light of the subject but that fact went right over your head. Fact is, I don't give a ratsazzz what someone else does as long as it isn't mandated on me.

 

[35WhelenAI]

The more a case is worked the sooner the head will separate. Not might, will.

 

[Tell]

That thread on incipient case head separation was awesome. And interesting that they said being over pressure isn’t necessarily causing that failure, just the over working of the brass. Thanks!

 

[35WhelenAI]

Over pressure loads work brass harder in the chamber, just like a die. Loses "elasticity" and needs more force to size which in turn leads to more working of the brass when sizing.

No brainer solution is knowing how to set up a die and shoot loads that are not over pressure. This is not new nor rocket science, however seems to be news.

 

[TaperPin]

It’s like the public service announcements every year around thanksgiving to not use a turkey frier in the garage, or learning to not run with scissors - you don’t know until you know.