1931 Sterlingworth and modern ammunition

[brmaher27]

Hello all,

I'm new to the forum and I apologize if this question has been answered before but here goes. I bought my first antique firearm around Christmas this past year and it's a 12 Gauge Sterlingworth. I found a chart online and have learned that my gun was made in 1931 (it's in the 130000 serial number range) and manufactured in Utica by Savage. I am curious about the ammunition I can use in the gun. Obviously steel shot is out of the question but I have tested it with a variety of 2 3/4" lighter loads that I had around the house. I've used some federal 1 oz #8 at 1180 fps and used some Remington managed recoil buckshot at 1 oz and 1200 fps on a hog hunt last weekend. I've been trying to keeps to around 1- 1 1/8 oz and under 1300 fps. My question stems from some posts online that most of these guns were in fact short chambered to 2 5/8" and cannot handle chamber pressures above 7-9000 psi. The loads thy I have been using are light by modern standards but the buckshot loads were marked as 1050 bar max (around 15000 psi) and the federal birdshot may be as high as 11500 psi according to SAAMI specs. My question is two parts: can I use 2 3/4" factory modem ammunition? Is it safe to assume that anything under 1 1/4oz at less than 1300 fps safe in my shotgun? I've been getting conflicting advice from people I know as well as the Internet and I'm curious if anyone has definitive answers.

Thank you all

[Researcher]

No one can tell you over the internet what ammunition may or may not be safe in a given shotgun. That requires a hands on inspection by someone with the proper tools.

The North American 12-gauge, 2 3/4 inch, progressive burning smokeless powder, high velocity, 1 1/4 ounce loads had been on the market nine years when your Sterlingworth was made. Western Cartridge Co. having introduced their Super-X 12- and 20-gauge loads in 1922. If your gun has seen any kind of use over the last eighty plus years, it has probably digested its share of them.

That said, most of us here tend to stick to lighter loads for high volume shooting like Doves and clay targets just to be easy on ourselves and old wood. I normally shoot 7/8 ounce reloads at 1200 fps which the Basic Loading Manual says run 6300 psi.

Contrary to the Olde Wives Tales about early smokeless powder loads being lower pressure, the heaviest 12-gauge loads our North American ammunition manufacturers were offering during the first two decades of the 20th Century, 3 1/2 drams of bulk smokeless powder or 28-grains of dense or smokeless powder such as Infallible or Ballistite, pushing 1 1/4 ounce of shot, had higher pressures than SAAMI specs which came into effect circa 1925. There were all kinds of lighter 12-gauge loads being offered, but we all know the North American nimrod's tendency to use the heaviest loads he can lay his hands on!! Even with their higher pressures, these older smokeless powder shells didn't produce the velocity that the progressive burning powder Western Super-X, Winchester Super-Speed, Remington Nitro Express, Federal Hi-Power or Peters High-Velocity did. That payload going out at higher velocity creates the recoil that is hard on old wood and old shooters.

When I'm out for mixed bag upland hunting I usually carry a Remington Nitro Express in the left barrel and a lighter load in the right. Been doing that for over fifty years.

[brmaher27]

Thank you for the help, I appreciate the quick response. I'm 22 years old and there aren't a lot of people my age who are shooting these guns so it's nice to get some quick help.

[brmaher27]

So I have an interesting update. I took the gun into a gunsmith yesterday and he ran a chamber length gauge and the chambers came out to 2 1/2". Needless to say I ordered son RST 2 1/2" shells for it last night. Has me thinking though because everything I've read has said the Sterlingworths had either 2 5/8" or 2 3/4" chambers but I watched him measure the chambers and saw the gauge with my own eyes so it's definitely 2 1/2". Has anyone else seen or heard of Sterlingworths with 2 1/2" chambers in 12 gauge?

[Researcher]

Chamber depth is considered to be the distance between the breech end of the barrels and the joint between the chamber body itself and the forcing cone, which reduces down to bore diameter. This is loosely based on the length of the "Fired" shell. Today, theoretically when the crimp opens on the shell being fired the end would land at the junction of the chamber and cone. Prior to WW-II many companies had the practice of holding the chamber about 1/8 inch shorter than the shell for which it was intended. Fly in the ointment is nominal measurements often differ from actual ones in both chambers and shells. A very good method I have found of measuring chambers without much outlay of cash, and is quite accurate enough for virtually any situation, is a common 6" flexible machinist's scale which you likely have. Hold the barrels with muzzles toward a light source, not necessarily a concentrated one a window is great, while looking into the breech and the cone will be thrown in a shadow. May have to move the barrels around a little until it is distinct. While still looking into the chamber simply slide the scale in until you observe the end coming flush with the shadow line & mark position of breech end with your thumb. Remove and read the scale. I usually repeat this a few times to insure I am getting a consistent reading, but you will be amazed how accurate this can be done. While I own a Galazan chamber gauge, I use this more often than not. The chamber body itself has a taper of about .005" per inch. Sometimes chambers were cut with slightly worn reamers giving a slight undersize chamber. If the chamber is a bit undersize a gauge made to "industry" standards will not go in to the true depth of the chamber. A.H. Fox Gun Co. shotguns are known for having tight chambers. The machinist’s scale method can be more accurate.

[Rogue Hunter]

Recently, someone described how they measured a 16ga chamber using the empty hulls of a 16ga and 28ga. They cut the brass and crimps off the shells, then slid the 28ga into the 16ga (may have to wrap some tape around the 28ga shell), and slide the shell into the chamber until it stopped, then push the 28ga shell down until it was flush with the breach end of the barrel. Then remove the hulls and measure the overall length of the hulls to find the chamber length.

[brmaher27]

So I have some Hevi-Shot Classic doubles 2 3/4" non-toxic shells. They are 1 1/8 oz, 1150 fps #4. Would it be a bad idea to fire these shells in my Fox next duck season? I only have 10 of them so it wouldn't really be a high volume thing. I've read that 2 3/4" shells made for vintage guns are typically safe in 2 1/2" chambers but I'm looking for more people's opinions.

[Mike of the Mountain]

Your Fox probably has 2 5/8" chambers, not 2 1/2". As long as your barrels are good those 2 3/4" shells should be fine. Have your gun checked first to be sure the wall thickness, etc are fine.