2-5/8 chambers ?

[Twice Barrel]

Researcher I don't think those are the pressures that that SAAMI originally established in the 1920s. The reason I say that is until fairly recently (in the last 20 years) pressures were routinely measured in LUP using the lead crusher system. In a quote from the Winchester Loading guide 11th edition copyright 1991 says " All pressure data listed as psi has been measured with the latest Piezo electric system showing actual pounds per square inch (psi) and cannot be compared directly to the old data which used the lead crusher method (LUP)".

[George Lander]

I've looked at RST shells and they about $10 per box. As I've mentioned above, I used the B and P's for my Cowboy action shooting. The B and P sub-sound's 12 gauge measure 2.62 in length with 7/8 oz shot
in #7-1/2 with 1100 FPS, but I don't know the PSI ? These are a real powder puff load as far as recoil.
I plan to us this Sterlingworth to occasionally hunt quail and use in Cowboy Action 'side' matches. Side matches are usually a Trap or Skeet type event the day before the actual match and only one box of shells are used. Since I will not be running a lot of ammo through it and from everyones replies, don't ya'll think I'd be OK with the B and P load described above ??

HardCash: At $10 per box the RST are what, @ $5 more than shells off the shelf. The reattachment of fingers is likely to run much higher.

Just My Humble Opinion.......George

[HardCash]

All great information. I did order from RST the 6 boxes of 12 ga Maxlite 1 oz. 2-1/2" #8 and 1 box of 12 ga Paper-lite 7/8 oz 2-1/2 #8.
The lady at RST said the Maxlite's PSI was 6400 and the Paper-lite is 6000 PSI.
I'm still going to call B and P about their PSI and we let everyone know.

[eightbore]

A Fox or Parker shotgun, as well as others of the era, were equipped with 2 5/8" chambers meant to be fired with 2 3/4" shells. Try to find fairly low pressure loads to shoot in your gun, but the length of the chamber of your gun was intended, by the factory, to be used with 2 3/4" shells, as Researcher previously posted. Do not have your chambers lengthened, an expensive and pointless project.

[Fin2Feather]

Since the mid-1920s, shortly after the Super-X type ammo loaded with progressively burning powders came on the market, the major U.S. ammo manufacturers have loaded to SAAMI specs --

Thanks! So Savage-era Foxes from the 30's and up; were they built to handle these pressures?

[mike campbell]

At the very heart of this discussion is the premise that "modern ammunition loaded to SAAMI specs of 11,500 psi" should not be used in firearms that were "designed for a service pressure of 9,500 psi." It's one thing to call it unwise, or even ill-advised. Quite another to call it unsafe which connotes likely to cause catastrophic harm to gun and shooter.

As I understand it, the current SAAMI max is 11,500 psi peak pressure as measured by transducer technology that was invented in the 1960's. I've seen no primary sources, but what I've picked up reading magazine articles is that the service pressure for 2 5/8 chambered guns was (about) 9,500 LUP as measured by lead crusher technology. I also glean that LUP pressures are NOT peak pressures, and there's no direct conversion between the two, but LUP measurements MAY be as little as 80% of true peak pressure. So, if they'd had the technology, a LUP pressure of 9,500 could well coincide with a peak pressure of 11,400 psi....is it coincidence that SAAMI set the max at 11,500 psi? Maybe.

So...AT MOST...we're talking about a 2000 psi delta between 1920's recommended service pessure of 9500 and a modern recomendation of 11,500. Service pressure is not about safety, it's about day-in, day-out wear and tear on a gun that has survived nearly 100 years of who knows how many 1 and 1/2 ounce duck loads.These guns were PROOFED at over 18,000 psi. Hard for me to believe that a factory 2.75" load generating pressures in that 2000 psi neverland is unsafe in a Fox designed to shoot the heaviest field loads of the day.

I find it very simple....if it's easy on my shoulder, it's easy on the gun.

And I think it would be sillly of me, if I were actually concerned about peak pressures in my Fox...I mean really, truly concerned....to believe that a "low pressure" handload is the answer, without testing it. IME, it would be foolish to trust published pressures, much less the understanding of a lot of hobby reloaders if it's dangerous pressures I was worried about. If I really care enough to want to know, I don't ask on the internet, I don't even ask the manufacturer. I just send 3 of ANY shell and a check for $15 to Tom Armbrust, and he tells me exactly what the pressure is. Tell him I sent ya, then share the data with us.

[HardCash]

Although I did order the RST shells, B and P informed me that the 12 ga sub sounds 7/8 oz 2.62 " #7-1/2 produce 5800 PSI.
At 5800 PSI, the B and P's have much less PSI than the RSTs.

[Researcher]

Excellant answer Mike!!!

[ASavageFox]

Thanks Mike.... that was really well said...

and i believe as well that the idea that someone might "loose fingers" shooting marginally higher PSI loads is silly... I could see blowing out a set of barrels but I don't think its going to turn into a stick of dynamite....

[Silvers]

After reading all the replies here I can imagine newbies would be confused when trying to pick out ammo for their old Foxes. I'm reminded of a Jack O'Connor piece he titled "Picking your Expert" that's been in a few of his books. If you have a copy it's good reading and you'll recognize some parallels with the opinions written in this thread.

Readers should know that some of the posters here are friends and see each other from time to time at shoots and shows. It just goes to show there is great diversity in the world and folks can often look at the same data and - right or wrong - interpret it differently.

I am of course on the conservative side and when I read published period data such as: service pressure maximum in the early 1900's was "3-1/2 tons (per square inch) in the summer months", it concerns me when gents are wanting to shoot modern SAAMI max shells possibly in pre-teens Foxes with low carbon steel frames, and/or in unknown service condition. Likewise when reading Askin's writings on 1929 ballistics and factory loadings, and trying to reconcile same with the Warning printed on 1930's and newer shotshell boxes that I cited here earlier. I have to believe that the engineers and ballisticians (and yes, lawyers) working for the big loading companies know more about their shotshells and how they should be used than some casual guys like me and others in cyberspace.

Do I believe Fox guns in otherwise good condition will blow apart with a mild overload? Absolutely not. Do I believe that volume shooting of high pressure shells will damage the gun? Yes.

Do I believe in lengthening chambers and/or forcing cones without having barrel wall measurements taken and reproofing the gun to the modern 18,000 psi proof standard - No. When Savage was routinely rechambering Foxes with 2-5/8" chambers sent in for repair back in the 50's, for then-modern 2-3/4" shells, that's what they did.

Practically speaking I've been into Foxes for years now and have seen many that are visibly stretched and off face, occasionally with loose ribs and barrel lugs. I wonder how many times they were overstressed through necessity or ignorance. I well remember a waterfowling trip to James Bay in Ontario many moons ago when the native guide ran out of shells for his old rusty Sterlingworth and started using 3-inch 1-7/8 ounce loads from our 1100 Magnums. He had to push them into the chambers with a stick of firewood. We all laughed about it because none of us knew better. His gun held those shells at that time and place, a real tribute to the strength of the Fox design. I wonder what happened to that SW since then.

I'll finish up with another reference to O'Connor. Unfortunately I can't find the piece right now but Cactus Jack was writing about ballistics, old guns and overloading same. It went something like this: a farmer walked past his mule every day and yanked sharply on the mule's ear just to show the animal who was boss. The mule winced in pain each and every time. Strange thing was the mule didn't need that torture; he was always ready and willing to do whatever had to be done, be it pulling a plow, hauling a farm wagon or skidding out sawlogs. That torture went on for years, mule continued to wince. Then one day after the ear yanking the farmer walked behind and the mule kicked the guy in the groin, causing some major injuries to important parts there and let's just say putting the guy out of business in that department. Afterwards the farmer said to his family, "gee he never did that before". Silvers

[George Lander]

Thanks Mike.... that was really well said...

and i believe as well that the idea that someone might "loose fingers" shooting marginally higher PSI loads is silly... I could see blowing out a set of barrels but I don't think its going to turn into a stick of dynamite....

He was asking about getting the chambers lengthened to 2 3/4 or even 3 inches which involves removing barrel steel which wasn't intended to be removed and which with store loads available could concievably cause the barrels to rupture just ahead of the forcing cones. Frank was right on with his remarks. Ansley built a very strong tough gun designed to handle the ammo available at that time. For me, I'd rather err on the side of fingers rather than try to save a few bucks.

Just My Humble Opinion........George

[HardCash]

Wow, this has been such great information for a new guy and now I feel like my supply of Remington STS Managed-Recoil 2-3/4 in #8-1/2's would be fine.
However since the B and P's are 2.62" in length and less professed PSI than the RST, I'll probably feed these on a regular basis to my Fox.

[DoubleGun]

Hardcash,
I'm not familiar with the B&P loads you are useing but it sounds like they were designed to be a low recoil, low velocity target load. Useually, low recoil and velocity also means low chamber pressures and I would bet you could use those B&P loads in your Fox for another hundred years without hurting the gun in the slightest.
Cheers, Pete

[eightbore]

There doesn't seem to be any difference in the bolting mechanism between a light 12 gauge Sterlingworth and a 3" chamber HE Super Fox. I have yet to see a Super Fox with a stressed bolting mechanism.

[Northern Bob]

There is an interesting picture on page 90 of McIntosh & Trevallion's book Shotgun Technicana. It shows a HE Superfox that came into the shop with 1/2 of the rib extention broken off. They say a .003" gap between the rotary bolt and rib extension led to the failure. They felt that the wear from many heavy loads eventually loosened it up enough to cause the gap. We don't have access in Canada to the low pressure RSTs and others, so for upland game and clays I either shoot low pressure hand loads or Kent Gamebore 1 oz. 12 gauge 2 1/2" (6000 psi) or 7/8 oz. 2 3/4" Winchester AA low pressure, low noise shells (6000 psi). In 20 I use the Gamebore 7/8 oz. 2 1/2" shells (6500 psi). I don't believe the extra 1/8" in the Winchesters makes more than several hundred pounds of pressure difference. I don't worry about shooting the low recoil, low noise shells in my 2 1/2" chambered British guns either. In fact, the Winchesters feel much lighter recoiling than the Gamebores and it is the wood I worry about most. A couple of weekends ago during a morning goose shoot I put some serious cracks in the stock head of my 10 gauge Parker hammer gun using 5800 psi hand loads with Kent TM shot.
We each have to decide what we put in our guns, but I don't worry about those types of shells in guns that are in good shape. I'll also shoot a bit heavier loads in American guns built for waterfowl, but only on game and not too many and not too often. Then again, I don't have the knowledge or experience of most of the posters to this thread.