Can anyone tell me what pressure a shotgun must test to go into production? I'm particularly interested n a 20 Gauge.

Ammo must test under 12,000 PSI.....but what magin of error is built into the firearm?

I doubt any real mfg. will give you an answer to this question. CIP and SAAMI set the max operating pressures for everything but I believe each manufacturer decides what 'proof' level to use. Design safety factor is a very touchy subject. You have to think about lawyers, lawsuits, grieving widows, etc.
C.G.B.

In the US; None. No tests required at all. Each manufacturer has his own test procedures. However, proof ammo is commercially made but I don't know the specs on it.
How much of a safety factor is in shotguns? Two times is my guess.
European countries have their own proof testing and each is different, varying widely from country to country. I recall that Germany and Russia use higher proof loads than others. I have the book on it if you are interested.
True, no maker is going to tell you anything about their testing protocol.
Are you going to produce shotguns?

quote:

Are you going to produce shotguns?

No.....absolutely not.

It's just that I have read so much about varying pressures of ammunition by simply changing primers (it has been reported that a primer change can affect pressures by as much as 5,000 PSI) and several other factors that it would be nice to know what the gun can handle when I'm loading 11,500 PSI hunting loads.

I have told folks to not get too concerned about primer usage when loading target loads of the 8,000 PSI range.....I'm now wondering about the accuracy of that.

Fabarm 20 gauge shotguns are proof tested at 1630 bar, that is 23641 PSI for example.

Jiri

Vapo,

I looked through the garage for my old IMR shotgun reloading pamphlet. They do specify every component down to the primer for each load. Tried to cross reference some loads where primer was the only change, and some did show big swings.

That said, the only gun I've seen destroyed by over-limit loads was a light, thin-walled game gun. There was a guy at the range I shot with once who had reloads he couldn't crimp because they were bursting out of the shell. Guy told me he was using the wrong wad, but it was okay, because he'd been using it in his 10 pound Browning trap gun for a long time without incident.

Of course, when he blew up his 6.5lb AyA double with the load, he couldn't quit talking about how suspect Spanish guns and steel were. Told everybody he could find how bad AyA and Spanish guns were.

Anyway, I think swapping primers on shotgun loads can lead to big pressure swings (percentage-wise). But heavy-built guns like 870's and Browning Citoris with their thick barrels probably compensate and prevent a lot of these problems.

And standard CIP proof pressure for 20/76 (20 3") is 1320 bar, that is 19145 PSI.

Jiri

quote:

Originally posted by Jiri:
And standard CIP proof pressure for 20/76 (20 3") is 1320 bar, that is 19145 PSI.

Jiri

I had been told years back that shotguns were tested to 20,000 PSI....but you know how reliable some information can be.

Thanks for the post.

This is what is advertised for the Japanese made Miroku, Winchester and Browning shotguns.

All hunting or sporting shotguns, over-and-under or semi-auto guns, by Browning, Winchester and Miroku fitted with original chokes, Invector, Steel Invector Plus, Stainless Steel Invector Plus, Teague, Briley, Midas, Diamond or Signature chokes, can fire high performance steel shot cartridges. Tested at the Liège test bench, high performance 1370 bars, in accordance with European law on the use of steel shot.

Here are all CIP TDCC free to download:
http://www.cip-bobp.org/homologation/en/tdcc_public

You can check whatever CIP approved caliber or gauge there.
Look for PE (proof pressure)

Jiri

quote:

Originally posted by Jiri:
Here are all CIP TDCC free to download:
http://www.cip-bobp.org/homologation/en/tdcc_public

You can check whatever CIP approved caliber or gauge there.
Look for PE (proof pressure)

Jiri

That's good info. Looks like the Japanese are happy to proof higher than normal high performance using 1370 bar, not far short of 20,000psi. Can bump my reloads a bit more for my Miroku O/U

If you get curious about what pressure a particular load of yours is, you can send it to Precision Reloading. I believe they want five shells loaded from your production run. They will run those through their pressure gun. They have a 12 gauge test barrel for sure. I never asked about other gauges or bores. I actually do not vary any component except I use Super Grex in hunting loads instead of that crappy buffer that Ballistic Products sells at a ratio of 1.3 to 1. When I had some shells tested, the super Grex buffered loads always showed less pressure than those loaded with BPI number 47, etc.