doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com pressure rating for 1220 12 ga ammo

Ted, I totally agree that ammo manufacturers do a lot of testing of their product, and I said as much. However, I don't believe that keeping us consumers totally in the dark would do anything to protect them from any real or fabricated product liability claims. Thus far, the onus has been on the shooter to avoid ammo that produces excessive pressure for the design or condition of their firearm. Manufacturers have zero control if you or I decide to fire one of their 3" mag shells in an old rattletrap gun with lengthened chambers, thin barrel walls, and deep pits. A box flap warning to not use ammo in Damascus barreled guns leaves out a lot of guns that should never be fired.

Sometimes, ammo makers attempt to protect idiots from themselves, such as by making .357 mag cases 1/10" longer than the .38 Spl. so they won't chamber in weaker guns. But the hot Hornady LeverEvolution .45-70 cases are actually 1/10 SHORTER than the original length, so they would easily chamber in a Trapdoor Springfield. It makes no sense. I assume they have some printed disclaimer on the box advising shooters to use them only in sound modern firearms in good condition.

If there was zero regulation preventing frivolous lawsuits against ammo makers, such as the FOPA, I'd expect there would be a lot more lawsuits fronted by anti-gun Democrats in an attempt to bankrupt the industry. They already tried, and that continues to be something they want. In such an environment, you and I both know the plaintiff's lawyers would subpoena the manufacturers for their secret pressure data... and they'd get it too.

Providing us that same data would make for more informed consumers, and perhaps actually lessen liability. The fact that some makers of low pressure ammo happily provide pressure data suggests that it isn't making them more susceptible to litigation, or they would hide it too.

You say you're stunned that some fools would simply guess and use off the shelf factory ammo in vintage doubles. But that isn't nearly as stupid as the gun owners who support anti-gun Democrats... yet this place is crawling with them.

I'm just wondering......what kind of a gun are you shooting, Little Creek? And what are you using the ammunition for?

I agree completely with Ted on this.

To push a hypothetical load of 1 1/4 oz. of shot to a desired velocity of 1220 fps requires a certain amount of pressure sustained for a certain time interval. Very different pressure curves with very different peak pressures can accomplish the same goal by utilizing different powders with different burning rates. For simplicity, I'm assuming all else (case, wad, primer, crimp, barrel length, etc) remains equal. A very fast burning powder is going to produce a higher peak pressure, earlier in the curve, to push a charge of shot to that hypothetical 1220 fps velocity. Naturally, the pressure will drop off faster than with a more progressive burning powder. Brisance of the primer is another big variable. I was very surprised to learn some years ago how much a simple change of primers can increase or decrease pressures, even though I knew some unknown difference was likely. Thankfully, GLS posted some testing results on the subject from Tom Armrest that detailed the risks in changing components.

So if a manufacturer of low brass promo ammo can achieve a certain desired velocity with 2 or 3 grains less powder by using a cheaper faster burning powder, it is likely they will do so to maximize profits. Using a few more grains of powder may mean little to those of us who load just enough for hunting. But it really adds up when you are loading millions of shells, and trying to please shareholders.

We've read and heard for years that "Low Brass does not mean Low Pressure." Supposedly, that statement has been tested for accuracy, but I have not seen those test results. Several years ago, I suggested that those of us who are interested could pool resources, and donate to a collective fund, and send a representative array of loads to someone like Tom Armbrust... knowing the data collected would only be good for a particular lot of ammo. Nobody seemed interested, so until something changes, we are going to be stuck with hearsay, second-hand info, conjecture, myths, and be cursed with seeing pressure data for powders that became obsolete when your grandfather was a young lad.

Low brass, high brass, no brass . . . . none of them are any indication of pressure levels. ACTIV shells were loaded to high enough pressures to cycle an old, dirty gas gun, possibly up to SAAMI levels, and had no brass at all.

In regards to this subject area, does anyone here shoot or know anyone who shoots the Federal 1.75 inch number 8s in Damascus guns with ample barrel and chamber wall thickness and in overall very good condition? I have some British 2.5 inch low pressure shells that I have shot in it but the idea of hunting upland with a pocket full of the shorter shells interests me. I havent shot it or these shells I mention in so long I have forgotten the name brand. I think they may be Ely shells??

Not low pressure Perry
If the barrels were reproved at some point for 2 1/2" 3 Tons that would be for a max. service pressure of about 9000 psi

Aguila 12ga MINISHELL 1 3/4” 5/8 oz. shot - 1,175 fps - 11,000 psi
Federal 12g SHORTY 1 3/4” 15/16 oz. shot - 1,145 fps - 9,500 psi

If you need low-pressure shells for something, it might be best to get into reloading for it, and it might be best if it is a 12-gauge. Damascus guns if safe, would remain safe with black powder loads, fluid steel 12 gauge can be loaded low pressure with modern components. I have found that trying to load low-pressure for 20 and 16-gauge cartridges to be frustrating. 12-gauge brass shells are available for purchase and hand-loaded without machinery. I haven't done it, but there are articles online about it.

Several guys have personally submitted loads to Armbrust, and there is an extensive collection of factory 16g pressures generated by the 16g reloading group
Here's an example, which is published old data so I think it's OK to share.



Of course components and powders change, so pressures change.
I think the data also confirms that it is not hard to reproduce vintage load, black powder, bulk and dense powder, pressures today

It's never been hard, until now... the canister powders we traditionally used for that task are discontinued or unavailable.

As posted recently, there is now available a small supply of 700X which can be useful for some 'lower pressure' loads.

I had no idea!! Thanks for that information Drew. Sooooo, it seems that shorter IS still powerful holds true. Hmmmm. I think I will remember and use that line!!