|
S |
M |
T |
W |
T |
F |
S |
|
|
|
|
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
|
|
|
|
Forums10
Topics39,508
Posts562,199
Members14,588
| |
Most Online9,918
Jul 28th, 2025
|
|
|
|
Joined: Mar 2005
Posts: 709
Sidelock
|
OP
Sidelock
Joined: Mar 2005
Posts: 709 |
Yes I'm trying to figure out what the gun was originally proofed for and it's original chamber length. It's my Army Navy so it is reasonable to assume it was properly proofed at one time, but there are no marks as to the tonnes or chamber length. The gun currently has a 2 3/4 chamber and appears to be in better shape then I first thought. It is off face by about 15 to 16 thousands and has been boughered by someone ham handed, but no real harm has been done. In fact it might still be in proof. I had originally planned to keep pressures below 6000 psi, but now 7500 psi seems reasonable. My next step may be to use barrel weight try to estimate what it was proofed at, but the tonnes marks are too obvious to miss. I'll get some pictures I must be missing something.
|
|
|
|
|
Joined: Feb 2008
Posts: 168
Sidelock
|
|
Sidelock
Joined: Feb 2008
Posts: 168 |
Should the chamber be a bit undersize, not uncommon on older guns, & be only .001" smaller at the end than the diameter of the gage, the gauge will show it about .200" short, which it isn't.
Better check your math there. Or your source. I seems to remember another regular came up with this error when telling how to measure chambers with a machinist scale.
|
|
|
|
|
Joined: Aug 2006
Posts: 322
Sidelock
|
|
Sidelock
Joined: Aug 2006
Posts: 322 |
You may want to fire off an e-mail to the Duty Archivist at the University of Glasgow and ask them. They maintain the Army & Navy records and will e-mail some information for free and for a modest fee they will copy the journal pages for your gun.
dutyarch@archives.gla.ac.uk
You could also ring them up,
+44 (0)141 330 5515
or Fax
+44 (0)141 330 2640
Mike
|
|
|
|
|
Joined: Dec 2001
Posts: 3,971 Likes: 103
Sidelock
|
|
Sidelock
Joined: Dec 2001
Posts: 3,971 Likes: 103 |
I believe if it was proofed at 1 1/8 ounces it was chambered for 2 1/2". If it was proofed with 1 1/4 ounces then it was chambered for 2 3/4".
John McCain is my war hero.
|
|
|
|
|
Joined: Mar 2005
Posts: 709
Sidelock
|
|
OP
Sidelock
Joined: Mar 2005
Posts: 709 |
True, but I can't find anything like that on the flats. There should be something somewhere. It feels like an ounce and an eight gun.
|
|
|
|
|
Joined: Dec 2001
Posts: 7,315 Likes: 618
Sidelock
|
Sidelock
Joined: Dec 2001
Posts: 7,315 Likes: 618 |
does the gun have the gauge inside a diamond on the flats? if so, and it is not followed by the letters LC, then it is 2&1/2". If the letters LC follow the gauge inside the diamond, then the gun was proofed with longer chambers. I hope that is of some help.
Firearms imports, consignments ![[Linked Image from i.imgur.com]](https://i.imgur.com/Ez9oz9Rl.jpg)
|
|
|
|
|
Joined: Dec 2001
Posts: 12,743
Sidelock
|
|
Sidelock
Joined: Dec 2001
Posts: 12,743 |
Should the chamber be a bit undersize, not uncommon on older guns, & be only .001" smaller at the end than the diameter of the gage, the gauge will show it about .200" short, which it isn't.
Better check your math there. Or your source. I seems to remember another regular came up with this error when telling how to measure chambers with a machinist scale. Well the Chamber of a shotgun has a taper of approximately .005" per inch. Therefore if the gage dia is .001" larger than the small end of the chamber it will stop short by .001"/.005" which = .200". I worked 35 years as a machinist & am quite familar with measuring things. I observed this by actual hands on experience, not Heresay. I had in fact built a set of chamber gauges for 12, 16 & 20ga guns, but after encountering this "Problem", I no longer use them much preferring my old Starrett 6" scale. If you see a problem with this math "PLEASE" do explain it, for I see none at all. I in fact once had to measure the end dia of a cone to very close tolerances. As I had bored the taper & knew the exact angle I did the measurement by building a plug to a known dia to fit the spindle of a depth Micrometer & then measured how far it would enter the cone. This was a matter of math & trig, but you don't need the trig to measure the length of a chamber. It is in fact quite Elementary.
Miller/TN
I Didn't Say Everything I Said, Yogi Berra
|
|
|
|
|
Joined: Apr 2011
Posts: 610
Sidelock
|
|
Sidelock
Joined: Apr 2011
Posts: 610 |
My chamber gauge is an inexpensive ID 6" leg caliper. Set it with just a little drag in the chamber. When you feel resistance, mark and measure.
|
|
|
|
|
Joined: Jan 2002
Posts: 866
Sidelock
|
|
Sidelock
Joined: Jan 2002
Posts: 866 |
If your gun was built per-1896 it likely has only black powder proofs which show neither chamber length nor weight of shot. If the gun is around 6 1/2 lbs it was built as a game gun and almost certainly had 2 1/2" chambers.It is because the early proof marks did not give the full story that they were upgraded over the years.BTW the 12 over LC (long chamber)in the gauge diamond refers to 3" or longer. My Scott pigeon gun has one set of original 1 1/4 oz. nitro proof marks, measures 2 3/4" and is stamped 12 over C.in the diamond.
Better to keep your mouth shut and be thought stupid,than open it and confirm.
|
|
|
|
|
Joined: Feb 2008
Posts: 168
Sidelock
|
|
Sidelock
Joined: Feb 2008
Posts: 168 |
Should the chamber be a bit undersize, not uncommon on older guns, & be only .001" smaller at the end than the diameter of the gage, the gauge will show it about .200" short, which it isn't.
Better check your math there. Or your source. I seems to remember another regular came up with this error when telling how to measure chambers with a machinist scale. Well the Chamber of a shotgun has a taper of approximately .005" per inch. Therefore if the gage dia is .001" larger than the small end of the chamber it will stop short by .001"/.005" which = .200". I worked 35 years as a machinist & am quite familar with measuring things. I observed this by actual hands on experience, not Heresay. I had in fact built a set of chamber gauges for 12, 16 & 20ga guns, but after encountering this "Problem", I no longer use them much preferring my old Starrett 6" scale. If you see a problem with this math "PLEASE" do explain it, for I see none at all. I in fact once had to measure the end dia of a cone to very close tolerances. As I had bored the taper & knew the exact angle I did the measurement by building a plug to a known dia to fit the spindle of a depth Micrometer & then measured how far it would enter the cone. This was a matter of math & trig, but you don't need the trig to measure the length of a chamber. It is in fact quite Elementary. Yes quite Elementary. Chambers have an INCLUDED TAPER of about .005 per inch of run. That means the taper from the CENTERLINE of the chamber. Therefore the DIAMETER of the chamber reduces by 2X that, or about .010 " per inch of run. Using your formula it would stop short by .100 ", and not .200 ". I hope this puts to rest the bad scoop posted here a while back.
|
|
|
|
|
