My apologies if this has been hashed over before. What exactly was the standard chamber length of 16 gauge guns, in either the U.S. or Europe, before the general adoption of the 2 3/4" length? I was always under the impression that 2 9/16" was the norm but I see a lot of reference made to 2 1/2".

"Confused in the Old Line State."

In the U.S. and Canada it was 2 9/16 inch. In Europe it was 65mm or 2 1/2 inch. While the "standard" length North American 20-gauge shell was 2 1/2 inch, when Western Cartridge Co. brought out their 20-gauge Super-X shell in 1922, they put it up in a 2 3/4 inch case. The next year when they brought out their 16-gauge Super-X shell it stayed in the "standard" 2 9/16 inch case with a load of 3 drams equiv. and 1 1/8 ounce of shot. Remington followed suit with their Nitro Express. In 1931, when Remington Arms Co., Inc. added the 16-gauge their John M. Browning designed autoloaders, the Model 11 and The Sportsman, the gun was made for 2 3/4 inch shells. Remington added a 2 3/4 inch 16-gauge shell to their line called the Auto Express with a load of 3 1/4 drams equiv. and 1 1/8 ounces of shot.



The one thing that seems confusing in this is that in 1926, Winchester lengthened the chambers and ejection ports of their Model 12s in both 16- and 20-gauge to take 2 3/4 inch shells. It makes sense in the 20-gauge to compete with Remington's Model 17 which was made for 2 3/4 inch 20-gauge shells from the get go. At that time the only 2 3/4 inch 16-gauge shells offered in the catalogues were older style shells like the old Winchester Leader that were offered in extra length. But, they were loaded with the older bulk or dense smokeless powders and carried a maximum load of 1 ounce, while the 2 9/16 inch Super-X/Nitro Express type shells loaded with progressive burning powder carried 1 1/8 ounce?!?

In their 1934 catalogues, Ithaca Gun Co. began stating that their 16-gauge guns were chambered for 2 3/4 inch shells. Savage in their Fox catalogues didn't begin mentioning 2 3/4 inch chambering until their 1938 catalogue.

65mm = 2.559"; 2 9/16" = 2.5625" or only .0035" difference, essentially the same. The British always used the nominal term of 2½" for their shells, but at least by the time OF Greener's 1910 edition he stated actual chambers were either 2 9/16" or 2 5/8". This was for 12ga, he didn't state whether the other ga's followed the same practise or not.

I have a twist bbl H grade 16ga Lefever with 3" chambers. As to when they were cut to 3" I simply cannot prove, but my money says they left the factory with them. I can think of no later time they would likely have been lengthened to this depth.

Thanks to Briley, all my 16's have 2 3/4" chambers and nice long smooth forcing cones.

Researcher does a good job of spelling it out. By WWII, standard chamber length for the 16ga in the US was 2 3/4", but it took some makers longer than others to get there. L.C. Smith was also very late in jumping on the 2 3/4" 16ga bandwagon. On p. 157 of Brophy's book, he shows a chart from 1936 that includes chamber lengths. By then, 2 3/4" was the standard for both 12 and 20ga Elsies. The 16 was still 2 9/16".

I own an old JP Sauer Number 2 hammergun in 16 Ga. - circa 1905, that I believe is unmolested and it appears to have original 70MM Chambers; along with the original 70MM Stamp on the barrel flats.

Longer than "standard" shells have been around just about as long as cartridge shotguns have been around. Prior to repeaters, which needed a certain length shell to function reliably, there were a plethora of shell lengths. In my 1903 UMC catalogue there were 12-gauge paper shells 2 5/8, 2 3/4, 2 7/8, 3 and 3 1/4 inch. The 16-gauge was available 2 9/16, 2 3/4, 2 7/8, and 3 inch. The 20-gauge was offered in 2 1/2, 2 3/4, 2 7/8, and 3 inch. In those days these longer shells didn't pack a heavier payload, but more and better wadding for a better gas seal which many serious Pigeon shooters thought to be an advantage. The first time I see the longer shells packing a heavier load was around 1912 for the 3-inch 20-gauge for the famous Widgeon Duck Club Parker Bros. guns and the J. Stevens A & T Co. pump gun. These 3-inch 20-gauge shells packed 2 1/2 drams equiv and 7/8 ounce of shot as opposed to the max load of 2 1/4 drams equiv and 7/8 ounce of shot in the standard 2 1/2 inch 20-gauge shell!!! Several of the early Ansley H. Fox graded 20-gauge guns, circa 1912-13 were chambered for the 3-inch shell of that period. WW-I and the rise of repeaters requiring a specific length shell to operate reliably did away with this plethora of shell lengths briefly.

Parker and Fox were not the only makers that offered longer than standard chamber lengths. I recently acquired a pivot lever, double hook Syracuse Lefever F grade 16 gauge with non-standard engraving and beautiful full choked 30 inch horseshoe damascus barrels. The serial number places the gun in the 1890 manufacture date range. When I checked the chambers I expected to find standard 2 9/16th inch chambers but was surprised to find that they are 2 3/4 inches.

Here's what I find for the Husky guns.

All Husqvarna Hammer guns are made with 65mm chambers.
The Husqvarna Drilling, Model 70, has 65mm chambers.

All Husqvarna Hammerless guns serial numbered before 165900 are 65mm. Higher serial numbers are always 70mm. Husqvarna never made 75mm chambers.
Exceptions are:

* Model 355 Extra Lyx which was always 65mm.
* Model 310X and 310XN which were always 70mm.
* Special orders. These are usually marked with chamber length on rib or by extractors.

An interesting note:

On my Browing Auto 5 the barrel reads 2 9/16 and the chamber reads 16-65





Enjoy
Mike

Early Browning A-5's in 16ga indeed had 2 9/16" chambers. I do not know the date they switched. Converting one to 2 3/4 normally involves more than just a re-chambering. Ejection port usually has to be opened in the front & I don't rcall what else is needed to make them function properly.

That's close enough. 2 9/16 in decimal would be 2.5625 and 65mm would be 2.5590, you will never see that difference.