16 ga. chamber length

[Shuck M.]

Greetings gents (and ladies),
I was looking throught the Michael McIntosh book (god bless), trying to find a way to determine which 16 and or 20 ga guns had 2 3/4 chambers. Now maybe this is a no brainer and all were x length after a certain point but I just don't know that.

Not to confuse matters, but I saw reference in the book ( a caption under a pic actually - I forget the page #) that stated something along the lines of 12 ga was 2 3/4, 16 was ~ 2 5/8 and 20 was ~ 2 9/16 with a disclaimer that they were actually a bit longer.

Anyway, were 16s and 20s really ever 2 1/2 and if so, when did they go to 2 3/4?
Thanks so much!

PS it's a great book with a lot of breadth, supplemental info. Is there another book with specs x date info and such?

[Twice Barrel]

Researcher has a nice write up on Fox chamber lengths and I hope he will post is again but when Fox started building guns the standard chamber lengths were 2 5/8 inches for 12 gauge, 2 9/16th inches for 16 gauge and 2 3/8th inches for 20 gauge. Chamber lengths were actually held 1/8th inches shorter in the belief that there would be a better gas seal if the hull protruded a bit into the forcing cones. There is some discussion about when chamber lengths were standardized to 2 3/4 inches, Savage says all of their guns were a standard length, however, I have several Savage era 16 gauge guns that have 2 9/16th inch chambers. I guess there are only two ways to tell for sure what your gun's chamber length is, the first is what is marked on the barrels and the second is to measure the chambers.

Aren't Foxes fun?

[sage1]

If you are concerned about pressures and gun wear, I have been told by two different gunsmiths, both referred from this forum, that shooting present day 16ga shells in the std 2 9/16" chambers was safe to do and not harmful to the gun. At this time I'm relying on their counsel but I am curious to know if that's a widely accepted practice.

S1

[Researcher]

FOX CHAMBERS --

The only two A.H. Fox Gun Co. catalogues, that I have seen, that state chamber lengths are the 1913 and 1914. They both state 12-gauge guns are regularly chambered for 2 3/4 - inch shells, 16-gauge 2 9/16 – inch shells and 20-gauge 2 1/2 - inch shells. That being said, virtually every 12-gauge Ansley H. Fox gun made in Philadelphia (other than the HE-Grade Super-Fox) that I've run a chamber gauge in shows about 2 5/8 - inch. The chambers of unmolested 16-gauge guns seem to run about 2 7/16 inch and 20-gauge guns a hair over 2 3/8 inch. A very few graded guns were ordered with longer chambers. Savage began stating chambered for 2 ¾ inch shells in their 1938 Fox catalogues.

All this being said there is a good body of evidence that back in those days chambers were held about 1/8 inch shorter than the shells for which they were intended. In the recently published book The Parker Story the Remington vintage specification sheets on pages 164 to 169 call for a chamber 1/8-inch shorter than the shell for which it is intended. Also in the 1930's there were a couple of articles in The American Rifleman (July 1936 and March 1938) on the virtue of short chambers. A recent issue of The Double Gun Journal carried an article on tests showing no significant increase in pressure from shooting shells in slightly short chambers. IMHO I don't much sweat that 1/8-inch in 12-gauge guns. On the other hand when one gets a 20-gauge chambered at 2 3/8-inch likely intended for 2 1/2-inch shells I do worry about folks firing 2 3/4-inch shells in such guns.

When the 16-gauge Super-X shell came out circa 1923, it was in the standard of the day 2 9/16 inch case, and the load was 3 drams equiv. of progressive burning powder pushing 1 1/8 ounce of shot. Capt. Askins wrote that he wished it had been put up in a 2 3/4 inch case, but then goes on to elaborate on the great work he did the previous fall with the new shell. In the 1930-31 time frame when Remington Arms Co., Inc. introduced their small gauge Model 11s and introduced "The Sportsman" both their 16- and 20-gauge versions were made for 2 3/4 inch shells. Remington brought out a 2 3/4 inch 16-gauge version of their Nitro Express shell with 3 1/4 drams equiv. of progressive burning powder and 1 1/8 ouce of shot and called them the Auto Express --



By the late 1930s all the U.S. ammo manufacturers were offering 2 3/4 inch 16-gauge shells, but 2 9/16 inch 16-gauge shells continued to be offered until the early 1960s when plastic shotshell cases began replacing paper. The 2 1/2 inch 20- and 28-gauge shells didn't get past WW-II

[J Mason]

I own 4 sterlingworths all phillys a 1912 20g 1913 16g 1919 12g and 1926 12g they all have short chambers, galazan sells a chamber and bore gauge $45 its worth every penny

[Researcher]

IMHO the chamber gauges are only of use if your chamber is cut to absolute industry specs. If your chamber is a little tight the gauge reads short and if the chamber is a bit loose it reads long.

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.

[Shuck M.]

Freakish amount of info here. In a good way!

So I have to ask; so you folks are buying/loading shorter shells?
On a shooter Sterlingworth, is it common to have the chambers lengthened without issue?

Thanks very much!

[Twice Barrel]

Over the years hundreds of thousands and perhaps millions of 2 3/4 inch shot shells have been shot through a variety of makers guns with short chambers without serious incident. So long as the chamber pressure of the round being fired does not exceed the original design parameters of the gun there is little to worry about. Having said that I shorten my hulls to the proper chamber length and roll crimp my shells not so much for safety of me or the gun but out of tradition. Besides it gives me something to do with my hands. If you want to shoot short shells in your short chambered guns RST makes a wide variety of high quality 2 1/2 inch shells that are very price competitive and will have them delivered to your door.

[nca225]

Shuck,

http://www.rstshells.com

or

http://www.polywad.com/index.html

are pretty good.

[NJdblgun]

New Era is making some nice low pressure 2 1/2" 16 ga. To your door, signature, or no signature required.