Question on Chamber Length

[Pete Margiotta]

I just bought my first Parker at a gun auction last week. It is a parker trojan, 20 gage, 28 inch modified and full, made in 1928. The chambers measure 2 3/8 inches long. My question is can i fire 2 3/4 modern target and game loads in this gun safely or do i need special shells. Do people typically have the chambers lengthed to allow use of 2 3/4 inch shells.

The gun has about 40 percent color case, the stock has been shortened to allow the installation of a 1 inch thick recoil pad. Would making changes (refinishing) hurt the value. It appears to be a shooter grade to me, but then again I have never owned one of these before. thanks for the help.

[Bill Murphy]

You will have to send us pictures of what you define as 40% colors. Many of use would put a 40% bright color 20 gauge Trojan away in a safe. Post some pictures to let us know how good your gun really is. If the colors are well faded, maybe you don't have to worry. After reading Bruce's great reply below, let me say Yes, No, Yes, Yes. However, as Bruce implies, the third reply guys are wasting their money. No one has ever blown up or damaged a 20 gauge Trojan with factory light target loads.

[Bruce Day]

1 Win AA
2. Rem STS

[Dean Romig]

I have a 1928 VH with identical chamber lengths and have shot quite a bunch of 2 3/4" AA ammo and it smacks me pretty good with those loads. It's okay to shoot this stuff in these guns but I suspect that pad was put on there for just that reason. If you reload you can develop your own lighter loads or simply buy 2 1/2" lighter loads from RST Shotshells.

[Bruce Day]

Dean, where do you find that 2 3/4" Win AA ammo?

As Bill implies, plenty of Parkers have had their chambers needlessly lengthened. The issue is not the fired shot shell length, because that is a non issue. The issue is the shot and powder charge in there. Blast away with whichever is more comfortable for you, 7/8oz or 3/4 oz and powder to go. These light Parkers don't like 1oz 20ga loads, I know, I've tried.

[Terry Schraner]

Some people will tell you it's ok to shoot shells longer than the chamber length- I wouldn't personally.Too many variables on pressure, plus you are shooting a keepsake , vintage heirloom.2 3/8 " cham.sounds strange - how did you measure the chambers? Try a chamber gauge. The only shells shorter than 2 1/2 in. I have seen from the first half of the 20 th century were 2 inch.But I still am lacking on 3 inch cham. gun info.Some guns may have been 2 7/8 in. chambers- go figure. I would say that a 3/8 inch difference on chamber /shell length is excessive for safety.Remember that todays standard loads are optimal as far as high tech is concerned-cases, powder, wads, etc.

[Bruce Day]

You know, the Double Gun Journal has had a great series of articles for the last ten years by Sherman Bell called " Finding Out For Myself" which addresses these issues.

[Dave Suponski]

I shoot 2 3/4" 20 gauge reloads using Remington and Winchester hulls for a good long while now. Load them light and they work great and don't hurt the gun or your shoulder. Some of this Promo junk thats out there hurts if your shooting a 9 1/2 lb gun!

Remington Hull,15.6 grains Hodgdan Universal,Claybuster Wad,Rem 209 Primer 7/8oz. shot 9,900PSI @1200 ft/sec.

[Bruce Day]

Damn Dave, that's even hotter than my load with those hulls. I shoot about the same but a little less powder and stuff them in both fluid and damascus barrels. I run about 1050-1100fps, just a few more inches of lead in front.

By the way Terry, Sherman Bell found a 300psi difference between the long and short shells. Great and well engineered articles and findings. Killed off a lot of old wives tales.

[Dean Romig]

Bruce, all the Winchester AA shells I have ever bought for twelve and twenty gauge shooting were marked right on the box 2 3/4" and that's what I'm referring to, not the length of the fired shell.

And it's not so much that these light Parkers don't like the heavier loads, even 7/8 oz. loads in most cases, I think it's the shooter (myself included) that don't like such loads.

[Bruce Day]

Fair enough Dean. However, the box lids lead to two erroneous assumptions, that these shells are 2 3/4" when fired and require chambers of 2 3/4". That's why we get the same question so many times. If I wasn't aware of the Bell findings and hadn't actually measured these shells, as Austin also just did, I would get confused also. Then also Parker chambers are notoriously hard to measure accurately and people often think they are shorter than they are.

You're probably right about the shooter not the gun. These Parker 20ga's are nasty ( to me anyway) with a 1 oz load but I have a little Browning Superposed in 20 that the 1 oz loads feel much better in. The Browning doesn't weigh but a couple ounces more....no explanation from me.

[Dave Suponski]

I may be wrong but I think the felt recoil in my O/U is less than my SxS guns.

[Dean Romig]

Softer especially in the lower barrel too, right?

It all has to do with the line of force. A higher stocked Parker will deliver much lighter perceived recoil than one of those with 3" DAH.

[Dave Suponski]

Ya..I guess.... I shoot lower barrel first. I tried it on a Parker by turning it on its side..Didn,t quite work out to well...:biglaugh:

[Pete Margiotta]

Thanks for all the good information. I will not touch the chamber and try the gun with some light target loads. There were several references to "these light 20s", I weighed this one at 7 pounds. When I said there were 40 percent case colors let me say that I did not think the colors were that brilliant. I will try to post some pictures when I figure out how to do it.

Regarding the question how I measured the chamber length, I used a starrett telescoping gage set to .685 diameter and placed it into the chamber until it stopped, then I measured the depth on the handle of the gage. thanks again

[Dave Suponski]

Pete,Be sure to keep in mind that chambers are tapered..698-.685. Ooops never mind!

[E Robert Fabian]

20ga. AA hulls 7/8 oz. 16.5 grs. 800x Rem 209p Rem RXP-20
7500 PSI 1200 fps.

Scott has a great 3/4 oz. load maybe he will post it.

I've loaded this down with about 15grs. 800x and you can shoot them all day.

Reloading data for the twenty stinks, open a new reloading book and there isn't one 3/4 oz load in it, but they list them for the 12ga., don't get it, there should be loads down to 5/8 oz.

[Austin W Hogan]

With respect to Mr Margiotta's question, and my post of a few days ago, his measurement may reflect chamber taper, and not chamber length.
I have attached page 17 of the current SAAMI ANSI standard. Note that the length specification for modern 12 ga cases is 2.76 - .100 inches, tolerance - .250. Remington and Winchester cases measure 2.66. This is 1/32 inch over 2 5/8, probably well within tolerances for paper and plastic. Also note the plus tolerance is zero.

I would like to call your attention to the modern chamber and forcing cone drawing below the case drawing. The modern 5 degree forcing cone makes the Parker forcing cone look like a bore obstruction by comparison. Although modern ammunition seems trivially longer, an extra 1/8 of chamber length is a great safety factor in the case of a case separation or other shell failure.

Best, Austin

[Dave Noreen]

Is this thread led off by my old friend Pete from down in Charles County and the Potomac River Gun Club at Rum Point? How is that Gene Mahoney pup of yours? I got a Mahoney setter in 2005.

I usually use our friend Morris Baker's 2 1/2 inch 20-gauge shells in my 0-frame 20-gauge VH-Grade, but I wouldn;t be above using my 3/4 ounce reloads in Remington STS hulls if the need arose. The chambers in my gun measure 2 3/8 inch, which is the way Parker Bros. chambered these old guns, 1/8 inch shorter then the 2 1/2 inch paper shells they were intended for. See pages 164 to 169 of The Parker Story.

Dave

[Bill Murphy]

Austin, thanks for bringing up the most important reason for not fooling with forcing cones and chambers. If a plastic hull separates from the brass and goes into the barrel far enough to allow another shell to be inserted behind it, your gun will blow up. Not that it might blow up, it will blow up. The forcing cone in an old gun will safely restrict a plastic shell from going past the cone and you will not be able to insert a shell behind the obstruction. Such an error will usually not go to the point of gun damage in a double barrel shotgun, but in a pump or automatic with a relieved forcing cone, it would be very easy to make an expensive mistake.

[Austin W Hogan]

Dave; Parker Pages editorially advertised for a citation to verify that chambers were cut shorter than shells in Parker's era. Ed Muderlak found a 1933 article based on 1932 work that we scanned and reprinted. That article was written by a person with good industry credentials but covered only one gauge and shell length; 3 inch 410 in 2 1/2 chambers. The three inch shells produced better patterns in the 2 1/2 inch chambers, but the author noted an inch of case was burned away in the process.
We will put out the call again in the next issue, in search of such information printed in the pre 1929 era. We know that Parker Bros was a member of the industrial fore runner to SAAMI in the 1920's when they began stamping "overload proved" on barrels, but I have not been able to obtain a copy of those standards through SAAMI.
I have always considered those tables in the Remington Salesmen's Catalog to be a typo/transposition when I have my editorial hat off. The current SAAMI standard clearly calls for short shells in long chambers. After reading your post I measured a few modern barrels with the equipment I used to measure the Super Fox. My Rem 3200 labelled "Trap" measures 2 7/8 inches; my ca 1985 Ruger Red Label marked 3 inch measures 3 3/16 inches, and my 11 87 trap barrel measures about 3 inches.
I have seen some anecdotal accounts that M21's were short chambered in the 1930's but have no physical evidence to verify this.
I obtained my first hunting license in 1950. My hunter training instructor warned us that "low brass" shells were no longer shorter and lighter as they were in the time before WW2, and that if we were told by an elder that low brass was ok in old single shots and break open guns, we should have the individual guns examined before using "modern" ammunition. I became a hunter safety training instructor in 1964, and my NRA correspondence course contained the same warning and information.
I also note in Stadt, that Winchester changed the designation of the M1893 to M1897 when they adopted the 2 3/4 chamber. Stadt also notes that 2 3/4 inch shells were labelled "Repeater" on the box.
We (Parker Pages) and I would really like to clear this up. A copy of that 1920's industry standard would be a good arbitrator.

Best, Austin

[Bruce Day]

Austin, SAAMI ( Sporting Arms and Ammunition Manufacturer's Institute) is headquartered in Newton , CT . Although its usually difficult to get one of these minimally staffed trade organizations to conduct any file research for persons who are not members of the organization, perhaps they would allow access to a researcher. Current standards are available on line. Maybe we have a member who lives in Connecticut ?

[Pete Margiotta]

Hey Dave, good to hear from you. My Mahoney setter "Jussie" just turned 7 in march. He is still hunting strong. We had a good season for woodcock and grouse. still shooting my modified 20 gage fox sterlingworth, but i am looking forward to shooting the parker. Is you dog working out well for you? pete

[Dave Suponski]

Sorry Bruce,Nobody here in Connecticut that I know of....

[Bill Murphy]

Austin, I don't have the drawings and specs in front of me, but we have found several instances of Parker Brothers memos and drawings that specify chambers 1/8" shorter than the shells meant to be fired in those chambers. We have also seen Parker Brothers hang tags specifying "2 5/8 inch chambers for use with 2 3/4 inch shells." We have also seen Parker Brothers orders specifying the same thing. I believe I have articles from older American Rifleman magazines noting that this short chambering is somewhat of an industry standard, although not universal. These Parker Brothers standards continued into the Remington era. I think it would be very easy to confirm by examining stock book entries from the twenties that indicate that a gun has been built with 2 5/8" chambers and proved and patterned with 1 1/4 ounce shot loads.

[Austin W Hogan]

Bill; I would really like to find a solid pre 1920 reference to this long shell in short chamber pattern theory. I think Askins the elder alluded to it but did not verify or explain it.
The bore jig I used to measure the Super Fox allowed me to make some quantitative measurements about this. One of my own "competition" guns is 136683 that dates from 1906 and was made to measurements by DuBray. It shoots beautifully tight, round patterns with both barrels. It is chambered 2 3/4 inches; the front of the forcing cone has a long taper ending at the barrel diameter of .740 inch at 6 inches from the breech, and one choke is more parabolic than like Oscar's "OGEE". I have a VHE with btfe and monte carlo, no safety 170789 , 32 inches that shoots similar round patterns. It is also 2 3/4 chamber with the forcing cone taper meeting the bore of .738 at 5 inches from the breech, and again a more parabolic choke in the left (full) barrel. A third 32 inch PH (207489) also reaches .738 at five inches, and the left barrel choke begins at .740 five inches back from the muzzle with a more parabolic than ogee taper. These dimensions do not duplicate the Super Fox, but the forcing cone taper and choke taper is of the same form.
These three guns tell me either that these owners sent their guns to Becker, or that King knew how to produce these patterns with forcing cone and choke profiles that did not involve jamming the case mouth into the forcing cone.
I have some "new" primed 3 inch ten gauge paper cases from two makers that have never been loaded or fired. They measure 2 7/8 inches precisely. I would like to find some unloaded twelve ga cases to measure.
The Super Fox has beautifully tapered chokes and forcing cones. The chambers measure .788 - 792 at 2 5/8 from the breech. The most common plug type chamber gauges are .792 wide. I did not measure the Super Fox with a blade gauge, but it may have measured 2 5/8.
Multiply fired modern 2 3/4 cases measure 2.66 +/-. Squaring the ragged mouth would shorten them a little. Were paper 2 3/4 cases also 2 5/8? We need some unfired cases to measure.

Best, Austin

[Robert Rambler]

"Were paper 2 3/4 cases also 2 5/8? We need some unfired cases to measure."


Austin, I just took a quick look at some unfired paper hulls I have stashed away and found a 12ga paper Federal "Monarch" measures 2 5/8, a 10ga "Leader" 2 5/8, and a 16ga "New Rival" 2 9/16. HTH, Bob

[Bill Murphy]

Austin, first you wanted a reference that guns were made for longer shells than the chambers. I gave you those references. Now you changed your mind and want a 1920s reference for how such guns pattern with long shells. You can find anything you want in Askins' articles because he was in the word selling business. One month he would write that short shells in long chambers throw great patterns, next month they will throw bad patterns. I just read an Askins article from 1916 where he tests shot containers. In the lengthy article, he doesn't really reach a conclusion or compare his patterns to patterns without using shot containers. Why did he do that. Simple, to sell another article next month, in which he may actually reach a conclusion. Or maybe not.

[Pete Lester]

A few thoughts. If indeed Parker chambered guns 2 5/8" for 2 3/4" shells and it was an industry standard;

How long was that practice carried on by Parker?

How long was that practice carried on by any other Maker?

Why did they change?

If they changed to meet "standards" did Parker or Remington lengthen chambers upon request or as part of any repair?

If Parker was still in business would they lengthen chambers on older guns or not? (I realize this is pure speculation).

Finally, because this is hot button topic I wonder if there may be those among us who think lengthening chambers is a good idea or OK but don't bring it up because they don't want what they might consider to be unecessary harsh critcism from the board?

If it doesn't matter if you don't do it, and the gun is a "shooter" and not unique, does it really matter much if it is done?

A Trojan 20 is a fine gun, I like mine, but it's a Trojan and I don't think lengthened chambers undercut overall condition/price if it's nice and original otherwise.

[Austin W Hogan]

Sorry Bill; I am really looking for a solid citation about this irrespective of who prepared it. I think that the experimental results of measurement of Parker competition guns, and Super Foxes are in direct conflict with the idea that long cases in short chambers produce better patterns than short chambers and short forcing cones. I would really like to find the original, and continuing publications that present the short chamber theory.

Anyway; I look forward to seeing you and Kevin Saturday.

Best, Austin

[Bill Murphy]

I think gas sealing was always the reason for 1/8" shorter chambers. I don't think that better patterns were ever a part of the equation. Pete, I don't disagree that lengthening chambers is a benign act on a less than collectable gun. However, no one can argue that it doesn't cost money, and doesn't sometimes lower the price of a gun when offered to a serious collector. I would rather have the extra steel in the area of the forcing cone than a couple of hundred pound feet of pressure. The very small rise in pressure has been proven empirically, the cost of drilling out barrels and the related shipping expense doesn't need to be proven. It is there.

[Pete Lester]

Hi Bill, not trying to argue just asking food for thought questions.

What about my other questions? Especially did Parker change to 2 3/4" 12 ga and if so when? Did Parker or Remington at any time ever lengthen or recommend lengthening chambers? Is there any documentation?

What does Turnbull, DelGrego, Kearcher etc. recommend today?

2 5/8" to 2 3/4" is not much of a jump but 2 1/2" to 2 3/4" is at least in my mind.

If Parker had survived into the modern times would they recommend leaving chambers alone of bring them to SAAMI standards (even if it was just for liability reasons)?

Seems to me we have a gamut of high condition orginal high grade guns to solid but very worn knockabouts. Altering a museum quality firearm is probably not a good idea. Lengthening chambers and forcing cones could be a good choice on a low grade shooter where performance matters more than collectibility

Shotguns have evolved and knowledge of how they perform has improved. I believe it is a given today that shotgun performance is improved through back boring, long forcing cones and chambers sized to current shells.

I have wondered if P Brothers thought it would be easier, cheaper and less trouble to market 2 5/8" chambers for 2 3/4" shells than to retool and consider modifying all existing guns to meet the changes occuring in the early part of the 20th century.

The cost of lengthening chambers is there but it is not significant to what the average price of gun is including Trojans.

Just my .02 Pete

[Bruce Day]

CHE 241,601 12ga is marked "For 2 3/4" shells". The chambers measure 2 5/8" to the beginning of the forcing cone.

[Dave Noreen]

The Remington era specification sheets for their Parker guns are reproduced on pages 164 to 169 of The Parker Story and show the chambers 1/8 inch shorter then the intended shell. A.P. Curtis did a couple of articles in The American Rifleman (July 1936 and March 1938) on the virtue of short chambers.

Pete, my Mahoney girl is 7 1/2 and is at the height of her powers. She is a bird machine. Currently her daughter is pregnant and I'm first in line for a puppy.

[Bill Murphy]

The A.P. Curtis articles that Dave mentions are the articles that I alluded to earlier in this thread. The Remington specifications that Dave mentions were dated as late as February 20, 1940, so, obviously, Remington kept the short chamber specifications to the end of production. Notice the marking on late Remington guns says "For 2 3/4" Shells" with no mention of chamber length. The chambers for 28 gauge and .410 bore guns were 1/16" shorter than the shells intended to be used.

[Bill Murphy]

Austin, I think you will find the "theory" of short shells in slightly longer chambers in the Curtis articles. I haven't read them for a while, but I think you will find that the "theory" involves gas rather than pattern. On the other hand, in the 1916 article I mentioned earlier, Askins mentions the 80% patterns that were shot in Edwin Hedderly's little gun. I thought he was referring to a 20, but later I see that Hedderly claims 80% patterns in his 16. Now, 94 years later, we find that Hedderly's smallbores were chambered very short, 2 3/8" in the 20 and 2 1/2" in the 16 as I recall.