Started using stamp about 1926, however the stamp is merely an indicator of pressures that Parker had been using for years .

No.

10,500 psi service loads , 13,500psi proof loads. TPS contains a table of Parker service and proof loads.

Parker did not distinguish between composite and fluid steel barrels for pressure loading.

Your 12 ga was intended to shoot as a standard load 1 1/8 oz, 3 dram ( or DRE) loads . A 3 DRE load will run 1150 to 1200 FPS. Stated maximum loads for 12s are 1 1/4 oz , 3 1/4 Dram , clearly a stout load.

I shoot Remington, Winchester , Federals , Fiocchi , RST . All off those companies make 1 oz 2 3/4 Dre loads and 1 1/8, 3dre loads.

Parker standard loads table . The measured speed is at 100 ft. Muzzle velocity would be higher and in the range of 1140 to 1240 or so.


This is a 1910 table for all Parker shot guns , composite and fluid.

Baschieri & Pellagri (B & P) have a 12 ga. load called the Comp One. It is a low pressure one ounce load. The pressure is 6530 psi. The Comp One 1 1/8 oz. load pressures are 8416 psi. These are published pressures. Both have a published velocity of 1160 fps. They are very soft shooting, but kill well. I can only use them in my external hammer guns. None of my sidelock or boxlock hammerless guns will shoot them reliably. I get misfires with them regularly because of failure to ignite the primers, from light primer strikes. There is something different about the rim shape and dims that lets the shell sit a tiny bit deeper in most chambers.

Don't ask me why the hammerguns will "light them off" every shot when the hammerless guns won't, but it's so. I haven't measured the firing pin protrusion on the hammerguns, but have measured it on several of my boxlocks that misfire with them, and too little protrusion isn't the problem. All are within specs.

But, I've shot up a couple flats of them and love 'em in the hammerguns.

Here you go Stan
Competition One 24 gr. = about 7/8 oz. 1160 fps at 500 BAR = 7252 psi
Competition One 28 gr. = about 1 oz. 1160 fps at 560 BAR = 8122 psi
https://www.baschieri-pellagri.com/e...g/1/index.aspx

Fiocchi acquired Baschieri & Pellagri last fall and apparently will produce the shells at their U.S. plant. I checked a few on-line retailers and none had any in stock.

Hmmm, those figures don't match the old ones I dug up. But, maybe they have changed since I last looked them up.

Thanks, Doc.

Stan, this has happened with various gun/ammo combinations over the years. One thing we have found here is some ammo is manufactured with slightly thinner rims and the shell will sit a few thou deeper in the chambers. That has caused some light primer strikes. If they were shooting at higher birds it didn't cause any misfires but if your gun was below horizontal or swinging fairly hard it would allow the shell to settle in lower in the camber. Maybe this will answer your question? Hope it helps.