2 1/2 vs 2 3/4

[MIKE FISHER]

This question has probably been beat to death in previous threads, so feel free to direct me to those. I have my great grandfather's fluid steel VH w/2 5/8" chambers, measured w/Galazan gauge. Do I need to use 2 1/2" ammo in it, or will 2 3/4 suffice?

IF 2 3/4 is OK, and I would only use regular field loads and target loads, are paper hulls necessary?

[John Campbell]

Most low velocity/low pressure 2 3/4" loads will be fine. And in this case skivved plastic cases, like Win AA or STS, are preferable to paper.

[Dean Romig]

Your VH was made for use with 2 3/4" shells. The original hang tag would have made that statement. Chambers were cut 1/8" shorter than the length of the shell to be used for the purpose of a better gas seal.

[Brian Dudley]

You will have no issues with 2-3/4" plastic shells.

[MIKE FISHER]

Thanks. Very good news in that AA is my hull of choice.

[MIKE FISHER]

Great to know. Had previously heard that the shorter chamber might cause unacceptable pressure rise. Appreciate the help.

[MIKE FISHER]

Thanks for saving me a good deal of time, effort and money. Much appreciated.

[Bruce Day]

Most low velocity/low pressure 2 3/4" loads will be fine. And in this case skivved plastic cases, like Win AA or STS, are preferable to paper.

What is the factual basis for this statement? Any Parker documents to support it ?

What specific pressures and velocities do you mean and what is the source of that information ?

And why are paper shells such as Federals inappropriate ?

[John Campbell]

BD:
With all due respect, the factual basis for my statement is threefold:

1) About 30 years of experience and tens of thousands of rounds in shooting such loads in "short" chambers of Damascus and fluid steel barrels.
2) Sherman's Bell's tests/report many years ago in Double Gun Journal.
3) Personal consultation with Tom Armbrust.


Okay, and at the risk of being tediously repetitious:

1) About any birdshot load in the 1100 - 1150 fps range. Notice I didn't say 000 buck.
2) I didn't use the word "inappropriate." I wrote "preferable." Because paper is a bit less compressible than plastic that's already skivved. But paper will still work...
3) According to Bell's and Armbrust's pressure-tested work, skivved 2 3/4" plastic hulls add about 25 psi to pressures as opposed to 2 1/2" hulls. Depending on the chamber/forcing cones of a specific gun.

For further insight, please consult Sherman Bell and/or Tom Armbrust...

[Bruce Day]

Parker provided plenty of documents about what they recommended. That information is stated on
1 hang tags
2 Small bore shot gun brochure
3 Parker load tables
4 Parker load table reproduced in TPS
5 Contemporary ammunition manufactures information as provided here by Dave Noreen


We have much detailed and specific information that has been reproduced here many times that is from Parker directly. Don't you feel that a questioner is entitled to know what Parker said to use with his gun instead of personal opinions ?

[Bruce Day]

Do you believe that a 25 psi pressure difference has any real world significance ? Wouldn't you agree that 25psi is about the same as normal variations in powder measures anyway ?

[Bob Hardison]

Bruce: "Wouldn't you agree that 25psi is about the same as normal variations..." I think Perry Mason would object because you are "leading the witness" :nono:. Best to all, Bob:)

[Bruce Day]

Well when you are talking pressures of 6000 to 9000 depending on powder type 25 psi is a non issue , at least to me. That is less than BB gun pressure.

[John Campbell]

Well when you are talking pressures of 6000 to 9000 depending on powder type 25 psi is a non issue , at least to me...

For the sake of those who may not have read and/or digested the Bell/Armbrust tests in Double Gun Journal, that aspect of their results is precisely the issue: It is insignificant.

In other words: Shooting low pressure/low velocity 2 3/4" skivved case cartridges in a 2 1/2" or 2 9/16" chamber does not raise pressures significantly. It is, indeed, a "non issue."

So, to be even more clear on the matter, this good fellow and his Parker are on safe ground. Assuming the barrels themselves have been checked and are found safe to shoot.

Finis.

[Bruce Day]

Low Pressure/low velocity is an opinion recommendation and is not based in the Parker documents. Some Parker listed loads are pretty stout, stouter than I care to shoot on any frequent basis.

For example, almost all the Parker 12ga's were patterned with a 1 1/8 oz 3 dre load, which provides about a 1200 fps speed. That is a standard loading for pattern efficiency/distance and lead. Patterning tags provide this information. Heavier loads are listed in other Parker sources as are mean maximum working pressures in psi, which became the SAAMI standards when the Small Arms and Ammunition Manufacturers Institute was formed. Parker maximum loads were SAAMI maximum loads.

While shooting less than maximum loads makes much sense, it is not a requirement for a Parker in good condition. Parkers are not delicate and were not designed to underperform.