Short Chambered 12's.

[B. Dudley]

I just found that my 1921 Trojan has the short chambers (2-1/2 or 2-9/16).
Any good sources for over the counter shells in this length?

[OH Osthaus]

Brian

I like the RST
http://www.rstshells.com/rst_classic...shotshells.htm

and the polywad vintagers
http://www.polywad.com/vintager.html

But "over the counter" for 2 1/2 will likely mean over the phone or web

There are other brands out there.

[Bruce Day]

Mr Dudley:

There is an entire thread " Fired Length of Commercial Shotshells" which some have found informative. Austin Hogan also provided a Parker chamber length chart and SAAMI specs. That thread and Mr Hogan's tables thoroughly covered the matter you ask.

You may be familiar with the Parker practice of chamber lengths and the concept of pressure sealing , if not, ask.

You may also be familiar with the Sherman Bell analysis of minimal short chamber length. If not, ask. I am not suggesting that even applies in the situation at hand, just that a person of serious interest in the matter might want to be aware of his findings.

FYI, here is a sample photo from that thread. Although RST shells are fine, a Parker shooter , with original chamber lengths in either fluid steel or damascus steel barrels, is by no means limited to using RST shells, although the RST owners are fine fellows.

[B. Dudley]

I just read that thread that you mentioned Bruce. I am just kind of surprised that my Trojan from the 20's would not have 2-3/4" chambers.
I will go to some of the local big box stores this week and see if any of them have some in 2.5" length.
If not, I will order some through RST or another vintage source. I plan on just hunting with this Trojan from time to time, not blowing through tons of ammo at the skeet range or anything. So I don't mind getting a few boxes of specialty shells for it.

[Bruce Day]

As you choose.

I trust my point is apparent, that over the counter commercial cartridges are seldom 2 3/4" when fired despite what is marked on the box, that Parker intended chambers to be shorter than the fired cartridge, and that the minimal pressure rise from a slightly long cartridge extending into the forcing cone is beneficial and intended. Measurements of original marked 2 1/2 shells that we have shown here are longer than 2 1/2 when fired. Measurements of original marked 2 3/4" shells that we have shown here are frequently shorter than 2 3/4 when fired.

TPS has a table listing chamber lengths. In the end though, measurement is the only sure way to determine what it is. Your Trojan at 2 1/2" is exactly what it is supposed to be, see table at p 519 TPS. Depending on present condition, it was intended to handle over the counter cartridges up to service working loads of 9500 psi, see table, p. 515. I am sure you realize that opens a broad range of suitable cartridges .

For what its worth, several of us last season went through about a pallet of AA's through various grades of Parkers, including A's, damascus and fluid, C's and D's.

[OH Osthaus]

Brian

There is a slim chance that Biekirchs may have them,

If by "big box" you mean Dicks or Ganders they won't carry such a specialty item

[J.B. Books]

Originally Posted by Bruce Day

Parker intended chambers to be shorter than the fired cartridge, and that the minimal pressure rise from a slightly long cartridge extending into the forcing cone is beneficial and intended.

Serious question, I am curious. Was this the case with all gauges; was this the case through every year of production?

Brian I don't believe you could hurt a 2 frame 12ga Trojan unless you purposefully set out to hurt it. I have shot every manner of shell from reloads to factory, from 7/8 to 1 3/8 ounce loads, both lead and bismuth through my first Parker, a 1913 Trojan 12. I have shot it a lot (thousands of shells) over the last 27 years. It remains as tight as the day it was made.

[Bruce Day]

Pete, I don't believe you could hurt a Trojan either either but you know how some people gasp at the mention of a heavy load. Your 1 3/8 oz loads likely exceeded recommended service limits, unless you didn't have any speed behind it, and your gun is still good for another 100 years I suspect.

Bell's reports showed minimal pressure rise in 1/4" short chambers in the order of 10%, anyway, thats what I recall.

If you look at fired lengths of shells in the period, they extended longer than nominal chamber length in all reported gauges. There was contemporary industry wide discussion of the extra hull length extending into the forcing cone and sealing better against gas loss than shells without the extra length. Muderlak discussed that issue at length. More recently, Austin Hogan had some tables on the length issue somewhere. I can't cite all the references off the top of my head, but I think we have also had PP articles about it, several I think. It might be a good research article to pull all the sources together again in a coherent manner, because this question comes up all the time to the new people. Up for it?

[B. Dudley]

I to not yet have a copy of TPS. But I have a sneaking suspicion that there might be one under the tree in a few weeks. :-)

My major concern is putting regular 2-3/4" shells, either Target or Game loads, through it with the 2.5" chambers. My gunsmith says not a good idea because of the higher pressures that it will cause, but he is not as well versed in these older guns.

If I am reading into what you guys are saying correct, then there should be no concern?

[Big D]

The typical shell found at Wally World or Dick's are liable to be high pressure loads. You might want to consider a better shell such as some of the low pressure offerings from Winchester.

My S-I-L bought a bunch of low priced shells ($4.11 out the door) at Dicks. They work OK in his Beretta, but are now causing cycling problems in my Grandson's 11-87. I haven't seen the gun to diagnose the problem, but it is either swelling of the steel cartridge head or plastic buildup in the chamber, I'm sure