Tndeer Logo

Page 1 of 1 1
Topic Options
#634899 - 02/27/08 12:06 AM Shotgun ~ Chamber Length
Locksley
16 Point


Registered: 10/23/01
Posts: 19744
Loc: Antioch TN

Offline
Shotgun 10, 12 ,16, 20 28 ga. Guns ~ Chamber Length
Quote by revdocdrew
Posted: 06 Sep 2006 09:39 am
Member



Joined: 28 Dec 2005
Posts: 913
Location: Glendale, AZ
This topic comes up so frequently that I thought I'd post this from the Fox Collectors Forum written by Researcher (who knows his stuff) This was published in The Double Gun Journal, Volume Fifteen, Issue 4

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. I have a 1920-vintage AE-Grade 20-gauge that letters as being chambered for 2 3/4 inch shells. Its chambers are 2 5/8 inches. 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.

Also, Askins mentions (Modern Shotguns and Loads, 1929) that for the last 3 years or so the US makers started to hold their chambers shorter since the constriction made when shooting 2-3/4" loads in 2-5/8" chambers was found to improve patterning.


Last edited by revdocdrew on 14 Sep 2006 04:10 pm; edited 2 times in total
_________________
Put your trust in God; but mind to keep your powder dry! Oliver Cromwell

revdocdrew
Posted: 06 Sep 2006 09:43 am
Member



Joined: 28 Dec 2005
Posts: 913
Location: Glendale, AZ
My only (possibly intelligent) contribution is that pressure and recoil are not necessarily the same thing. It would seem wise to avoid any increase in recoil when shooting a classic SxS that may have 100 year old wood. I can certainly testify that recoil is brutal shooting AA 2 3/4" 7/8 oz. target loads in my 2 1/2" chambered 20g 1922 Trojan (which actually measures closer to 2 and 3/8".)

Larry Brown
Posted: 07 Sep 2006 08:36 am
Member



Joined: 26 Apr 2005
Posts: 453

Drew, that's a good point--and I'd guess that the worst problem with 2 3/4" in short chambers would be with 20's, because they had the shortest standard chambers of all, at 2 1/2". If you had a gun with very short cones, the case mouth might almost make it into the bore. The recoil with your Trojan might be worse because of a short and possibly low stock. That's often an additional issue with old 20's. I shoot factory 20's all the time in an Arrieta that's certainly lighter than your Trojan, but of course it has modern chambers and modern stock dimensions.
revdocdrew
Posted: 14 Sep 2006 04:09 pm
Member



Joined: 28 Dec 2005
Posts: 913
Location: Glendale, AZ
L.C. Smith changed the 20 ga. from 2 1/2" to 2 3/4" in 1936, my L.C.Smith 16 ga. circa 1939 has 2 9/16" chambers. A 1938 Fulton was still 2 9/16".


ITHACA CHAMBERS -- The last Flues period catalogue (1925) states -- "Unless otherwise ordered Ithaca 28 Gauge and 20 Gauge guns are chambered for the standard 2 1/2 inch shell, 16 Gauge and 12 Gauge for the standard 2 3/4 inch shell and 10 Gauge for the standard 2 7/8 inch shell. Longer chambers are furnished if ordered on new guns without extra charge, but it should be remembered that shells of standard length do not give quite as good results in chambers which are longer than the shells and it should be remembered that extra long shells are more expensive and it is much harder to find a dealer who carries extra long shells in stock." I find that 2 3/4 inch pretty strange in the 16-gauge, because 2 9/16 was the standard 16-gauge shell until WW-II!?! None of my earlier Flues period catalogues mention chamber lengths.

Beginning with the first NID catalogue in 1926 they state -- "Unless otherwise ordered Ithaca .410 Cal. and 20 Gauge guns are chambered for the standard 2 1/2 inch shell, 16 Gauge for 2 9/16 inch, 12 Gauge for 2 3/4 inch and 10 Gauge for the standard 2 7/8 inch shell." The 28 gauge doesn't appear in NID period catalogues until 1932 though they did make some. Beginning with the 1927 catalogue the sentence is changed to -- "Unless otherwise ordered Ithaca .410 Cal. guns are chambered for the standard 2 1/2 inch shell, 16 Gauge for 2 9/16 inch, 20 and 12 Gauge for 2 3/4 inch and 10 Gauge for the standard 2 7/8 inch shell." Ithaca catalogues for 1926, 1927, 1927-1928, 1928, 1928-1929, 1929, 1930, 1931-1932, 1932, No. 50F, and No. 51S, all list 16-gauge as 2 9/16-inch chambers. Beginning with the 1932 catalogue the 28-gauge with 2 7/8 inch chamber is added to the list and it also introduces the 3 1/2 inch Magnum Ten Gauge. By Ithaca catalogue No. 51F the 16-gauge is finally listed with 2 3/4-inch chambers and the 410-bore with 3-inch chambers. I believe the catalogues No. 51 equate to 1934.

_________________
Put your trust in God; but mind to keep your powder dry! Oliver Cromwell
revdocdrew
Posted: 14 Sep 2006 07:05 pm
Member



Joined: 28 Dec 2005
Posts: 913
Location: Glendale, AZ
From the Parker Gun Collectors Forum:
http://www.parkergun.org/forums/forum1/2164.html

Parker "borrowed" English chamber measurements (for paper shells) and manufactured 12ga and 16 ga 2 1/2" chambers until about 1895...then the 12 ga went to and continued with 2 5/8"chambers (16ga went mostly to 2 9/16" ) for a long period...possibly until near the end of regular Parker production...about 1934. By 1930 most (but not all) shotshell and gun manufacturers agreed to 2 3/4" chambers for field and target guns. As far as I can determine, 2 5/8" shells were manufactured at least until 1940. The 1945 Stoegers Shooters Bible lists Xpert and Xpert Super Skeet loads, Ranger Field loads, and Leader Staynless loads as being available in 2 5/8" 1 1/8oz. By that time all Super-X, Super Speed, Leader Super Speed, Ranger Brush Loads, etc were 2 3/4" 1 1/4oz. Original chamber length is a strong clue as to the correct MAXIMUM shot load.

I don't know what to make of the 1920 "2 1/2" Standard Shotgun Chambers drawing" (p519 TPS). Some information is obviously missing. In original 12ga chambered guns (frame size #2 and smaller), a 12ga .798 chamber gauge will stop most commonly at either 2 5/8" or 2 3/4". Why does a .798 gauge not stop at 2 1/2" as depicted in the drawing? The difference due to chamber taper is of course, negligible, but why would Parker make a "shop drawing" and not use it? Why was this 2 1/2 inch "standard" adopted in 1920 when Trap Guns were standardized at 2 3/4 inch chambers much earlier? Is there documented evidence to validate the "better gas seal" claim? Is there "short chamber" patent?

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. I have a 1930-vintage VH-grade 0-frame 20-gauge and its chambers are 2 3/8 inches intended for the old 2 1/2 inch shells, eight years after the 20-gauge Super-X shell was introduced in a 2 3/4 inch case!!

New subject: Why would manufacturers continue to make 2 5/8" shells 15 years after they had adopted a 2 3/4" standard?

Presumably because 2 5/8" shells were designed to work in 2 5/8" chambers with a maximum 1 1/8oz shot load AND those shells worked equally well in 2 3/4" chambers. If there was gas leakage around the overpowder wad or in the forcing cone, no one was the wiser...or complained apparently. We shoot 2 3/4" shells in 3" chambers today (ex Ruger Gold Label) and no one raises an eyebrow. Conversely, 2 3/4" 1 1/4oz loads were NOT DESIGNED to work in light guns with 2 5/8" Chambers.

Things are different now. No one makes 2 5/8" chambers anymore and we have shot loads at 1 1/8oz (and less) for 2 3/4" shells.

The 1923 Remington catalog has many 12ga shell listings and about 90% are 2 5/8". Even the Nitro Club Trap shells were 2 5/8 inch 1 1/8oz at a time when Trap guns had 2 3/4"chambers. Apparently there was no disadvantage.

If you read the DGJ articles, you will see that the difference between a shell made for 2 3/4" chambers, when shot in a 2 5/8" chambered gun versus a 2 3/4" chambered gun is approximately 300psi out of a total load psi of 7000-10,000psi.

Larry Brown
Posted: 15 Sep 2006 04:47 am
Member



Joined: 26 Apr 2005
Posts: 453

The main reason that manufacturers continued to make short shells (2 5/8" 12's, 2 9/16" 16's, and 2 1/2" 20's) after they switched to a 2 3/4" standard is quite simple: There were still a lot of short-chambered guns out there. And while shell length does not increase pressure significantly in and of itself, the 2 3/4" factory shells were loaded to higher pressure standards than their short predecessors. This was not a huge increase, according to sources from the period--about 1,000 psi. But the new, longer shells definitely were higher pressure than the older, short ones.

I have the two American Rifleman articles to which Researcher refers above. And here's the reason why better patterns resulted from slightly overlength shells in short chambers (or chambers marked 2 3/4" that weren't really that long): Remember that we're talking the pre-WWII days, paper cases and felt or cork wads, no plastic shotcups. One reason for pellet deformation back in those days is that the unprotected pellets would slam into the walls of the forcing cone when the gun was fired. However, if the paper case mouth opened into the forcing cone, the mouth of the shell itself afforded some protection to the shot charge, on its initial contact with the bore. Tests established that slightly shorter chambers resulted in tighter patterns. Some trap shooters even when so far as to shoot 3" shells in 2 3/4" guns. Today, of course, with plastic hulls and wads, there's no longer any pattern benefit to shooting longer shells in short chambers, because the wad itself does a much better job of protecting the shot.
revdocdrew
Posted: 18 Sep 2006 03:50 pm
Member



Joined: 28 Dec 2005
Posts: 913
Location: Glendale, AZ
From another forum:

The Winter 2001 Double Gun Journal has the article by Sherman Bell called "Finding Out for Myself" Part V "Long Shells in Short Chambers".

After extensive testing carried out in a very professional manner he concludes:

"With loads that are sensible in a light 21/2 inch gun, we see no dangerous pressure levels produced. I see no reason, related to safety, to modify an original 2 1/2 inch chambered gun to shoot 2 3/4 shells, If The 2 3/4 Inch Load You Intend To Use Would Develop Pressure That Is Safe In That Gun, When Fired In A Standard Chamber!

16gaugeguy
Posted: 18 Sep 2006 05:52 pm
Member



Joined: 12 Mar 2005
Posts: 1479
Location: massachusetts
Prior to the advent of folded crimps, shot shells had rolled crimps. The shell mouth acted as a gasket to both funnel the shot into the forcing cone and to prevent blowby as the fiber and/or felt wad passed the slight, but even constriction. With the advent of folded crimps, shell mouthes were being ripped off and gas was getting into the pattern to a degree. This caused problems of its own.
Jeff Mulliken
Posted: 18 Sep 2006 07:08 pm



Joined: 25 Jul 2006
Posts: 108

Another reason short shells continued to be made is that there was demand, especially from pump and autoloader owners. Safety aside, their guns would not cycle the longer shells as the mechanisms and ejection ports were not long enough.
revdocdrew
Posted: 21 Oct 2006 04:58 pm
Member



Joined: 28 Dec 2005
Posts: 913
Location: Glendale, AZ
More pearls from Researcher on the Fox Collectors site:

When Western brought out the Super-X in 16-gauge it came in a 2 9/16 inch case. Up through at least the 1937 Western Ammunition Handbook only 2 9/16 inch hulls are listed for 16-gauge. The next paper I have is 1941. The Winchester Ammunition Guide offers the Super-Speed in both 2 9/16 and 2 3/4 inch. The load in the short case was 3 dram equiv. and 1 1/8 ounces of shot while the load in the 2 3/4 inch case was listed as 3 1/4 dram equiv. and 1 1/8 ounces of shot. By the way Winchester and Western in those days were just the two sides of the same Olin Corporation coin. The Western Ammunition Guide calls the 2 3/4 inch hull 16-gauge Super-X a magnum but doesn't list the dram equiv., but it is still the 1 1/8 ounces iof shot. The 1 1/4 ounce 2 3/4 inch 16-gauge magnum didn't come along until the 1950s.

Remington seemed to be the leader in lengthening the 16-gauge hull. When Remington brought out their Model 11 and "Sportsman" Autoloading shotguns in 16-gauge along about 1931 or 2 they were made for 2 3/4 inch shells and their catalogues stated "..the new 16-gauge Auto Express Shell has been developed for use in this model as well as the Sportsman."

Ithaca first starts listing their 16-gauge NIDs as being 2 3/4 inch chambered in the 1934 catalogues. From 1926 through 1933 they list 2 9/16 inch.
I posted part of this on another thread before I noticed this one in Announcements. All of the data comes from George R. Watrous' The History of Winchester Firearms 1866-1966. Thomas E. Hall, Curator of the Winchester Museum when it was in New Haven, and Pete Kuhlhoff, author and outdoor writer, were editors.

M/1897 Winchester

16 gauge was first offered in Feb. 1900 with 2 5/8" chamber. This was changed to 2 3/4" chamber in 1931 (The same year that Western Cartridge Co. acquired the failing Winchester Repeating Arms Co.). 16 gauge was last listed in 1950.

M/12 Winchester

16 gauge was first offered in 1914 with 2 9/16" chamber. This was changed to 2 3/4" chamber in 1927.

I wonder why Winchester chose to increase the chamber length on the M/12 four years ahead of the M/1897?

Gordonstoun
Posted: Wed Oct 17, 2007 4:47 am






Joined: 04 Aug 2004
Posts: 27


What about Lefever Nitro Express guns? Did they have 2 3/4" or 2 9/16" chambers?


revdocdrew
Posted: Sun Oct 21, 2007 4:10 pm



Member



Joined: 28 Dec 2005
Posts: 1682
Location: Glendale, AZ

Larry Brown provided another resource:

The Eley tests of long shells in short vs long chambers can be found in Gough Thomas' Gun Book, pp 260-262, "Danger in Case Length".

_________________
LC Smith "A thing of beauty and a joy forever."

Gene Hill Shotgunner's Notebook 16 gauge "...the darling of the upland gunner..."


16ga. wrote:

New subject: Why would manufacturers continue to make 2 5/8" shells 15 years after they had adopted a 2 3/4" standard?

Presumably because 2 5/8" shells were designed to work in 2 5/8" chambers with a maximum 1 1/8oz shot load AND those shells worked equally well in 2 3/4" chambers. If there was gas leakage around the overpowder wad or in the forcing cone, no one was the wiser...or complained apparently. We shoot 2 3/4" shells in 3" chambers today (ex Ruger Gold Label) and no one raises an eyebrow. Conversely, 2 3/4" 1 1/4oz loads were NOT DESIGNED to work in light guns with 2 5/8" Chambers.



As a collector of old shotshells, I believe the shorter lengths were kept until the folded crimp shells finally took over. At least it seems that chronologically the shells are such. 2 5/8" 12Ga, 2 9/16" 16 Ga, and 2 1/2" 20Ga, seemed to stay right along with the roll crimp ammunition..... The loaded shell lengths are close to the same when roll crimped, when compared to the then new folded crimp 2 3/4" shells, so it could have been done for cycling dependability in repeaters as well.....
I remember even into the fifties as Federal "hung on" to the roll crimp that the 20Ga "Monark" was still a 2 1/2" hull. The short Magnums were introduced in that decade as well.... Federal's 20Ga item load with a full 1 1/8oz of shot, sported an extra high brass, a full 2 3/4" maroon colored hull, but still were roll crimped! They were so l o n g that a special box was needed! They looked like a loaded 3" 20Ga with folded crimp that came along a few years after.... These are the only 20Ga roll crimped shells I remember in the paper era that were longer than the earlier 2 1/2" standard...

Slidehammer


http://www.16ga.com/forum/viewtopic.php?t=1983


Edited by Locksley (02/27/08 12:28 AM)
_________________________
To know wisdom and instruction; to perceive the words of understanding;"The greatest pain a man can suffer is to have knowledge of much, and power over nothing" - Herodotus

Top
#634940 - 02/27/08 04:04 AM Re: Shotgun ~ Chamber Length [Re: Locksley]
Locksley
16 Point


Registered: 10/23/01
Posts: 19744
Loc: Antioch TN

Offline
By Layne Simpson, Field Editor, Shooting Times.
Page Two

No. 11
Do 2 3/4-Inch Shells Pattern More Uniformly In A 2 3/4-Inch Chamber Than In A Three-Inch Chamber?
My father is of the opinion that the firing of 12-gauge 2 3/4-inch shells in a gun with a 2 3/4-inch chamber produces better patterns than when they are fired in three-inch chambers. If this is true, the performance of short shells must be awful in guns with 3 1/2-inch chambers. Do you agree?
Through the years I have pattern-tested enough short shells in long chambers to become convinced that the information you have received is more speculation than fact. Only a few weeks ago I fired several 12-gauge 2 1/2-inch and 2 3/4-inch loads in an autoloader with a three-inch chamber, and the patterns they produced were just as uniform as those shot with three-inch shells. I then took the experiment another step by firing those three shell lengths in another shotgun with a 3 1/2-inch chamber and could tell no difference in pattern quality than when 3 1/2-inch shells were used. I have also experienced the same results with other gauges. Sometime back I bought a 1930s-vintage 20-gauge double with 2 1/2-inch chambers and pattern tested it with shells of that length made by the British firm of GameBore. I then had the chambers of the gun lengthened to 2 3/4 inches, and pattern quality with those same shells remained the same when fired in the longer chambers. The 2 1/2-inch shells also produced beautiful patterns when fired in a 20-gauge gun with three-inch chambers.
No. 12
If A Three-inch Shell Fits In My Gun’s 2 3/4-Inch Chamber, Can I Fire It Safely With The Longer Shells?
The barrel of my 12-gauge shotgun is marked for 2 3/4-inch shells only, yet a three-inch shell will easily slip into its chamber. Does this mean it is safe to shoot three-inch shells in my gun?Absolutely not. The linear dimension used to identify a particular shotshell refers to the length of its fired case and not that of the loaded round. Actual length will vary slightly among various brands of shells, but those designated as 2 3/4 inches usually measure around 2 5/16 inches before firing and 2 5/8 to
2 11/16 inches after firing. Three-inch shells usually measure from 2 1/2 to 2 5/8 inches before firing and lengthen to just under three inches when fired. Since the 2 3/4-inch chamber of a shotgun will usually measure at least that long, and sometimes slightly longer, you can see how an unfired three-inch shell will drop right into it. Firing shells of excessive length for the chamber can generate dangerously high pressures for the following reason: The inside diameter of a shotgun barrel rapidly becomes smaller just forward of the front end of the chamber in an area called the forcing cone. When a three-inch shell is fired in a 2 3/4-inch chamber, its crimp section opens into the forcing cone and in doing so effectively reduces bore diameter at that point. If the shot charge and wad column are required to squeeze through this partial obstruction, chamber pressure can increase.
http://hunting.about.com/od/shotgun/l/aastshotgunfaqb.htm
_________________________
To know wisdom and instruction; to perceive the words of understanding;"The greatest pain a man can suffer is to have knowledge of much, and power over nothing" - Herodotus

Top
#635334 - 02/27/08 10:23 AM Re: Shotgun ~ Chamber Length [Re: Locksley]
Blue5
Woodpile Boys
16 Point


Registered: 09/21/04
Posts: 16852
Loc: Chapel Hill, TN

Offline
good info Locksley!
_________________________
"It's What We Do!"

Top
#635548 - 02/27/08 11:56 AM Re: Shotgun ~ Chamber Length [Re: Blue5]
Locksley
16 Point


Registered: 10/23/01
Posts: 19744
Loc: Antioch TN

Offline
 Originally Posted By: Blue5
good info Locksley!

Yes I hope so there are lots of nice old shotguns that need to be saved from excess pressure out there., and lots of fingers to save.
_________________________
To know wisdom and instruction; to perceive the words of understanding;"The greatest pain a man can suffer is to have knowledge of much, and power over nothing" - Herodotus

Top
Page 1 of 1 1


Moderator:  RUGER, Bobby G, Unicam, CBU93, stretch, TurkeyBurd, Kimber45, Mrs.Unicam, Crappie Luck, gtk 
Hop to:
Top Posters
4106599
RUGER
88400
Deer Assassin
65979
BSK
62020
Crappie Luck
51392
spitndrum
Newest Members
yarddawg54, schiesser, bigdoc, Bggamehunter, willy2763
13605 Registered Users
Who's Online
7 registered (RAFI, Haf2Hunt, gil1, SEC, lonewolf1330, gun nut) and 58 anonymous users online.
Forum Stats
13605 Members
43 Forums
100233 Topics
1180122 Posts

Max Online: 788 @ 11/11/13 08:06 PM
Moon Phase
CURRENT MOON
December
Su M Tu W Th F Sa
1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30 31
Forum Donations
The TnDeer.Com Deer Talk Forum is for Tennessee Deer Hunters by Tennessee Deer Hunters. If you enjoy using our Talk Forum and would like to contribute to help in it's up-keep. Just submit your contribution by clicking on the DONATE button below and paying with PayPal or a major credit card. Any amount is much appreciated. Thanks for your support!

TN Burn Safe

Generated in 0.006 seconds in which 0.001 seconds were spent on a total of 14 queries. Zlib compression enabled.