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chamber length
Posted: Sun Oct 05, 2008 8:12 am
by terc
dmill, I have a very late, Savage made,A grade. The barrels are marked 2 3/4". My Galazan gauge shows them to be slightly less than 2 1/2". I discussed it with a few people at this years Vintagers shoot. They seemed to feal that maybe the forcing cones have a very gradual taper beyond 2 1/2" that can't be measured with my type of gauge. I really don't know the answer, but I am interested in others opinions.
terc
Posted: Mon Oct 06, 2008 7:43 am
by Knothole
terc; chamber ends and the forcing cone begins. Fox type cones are sharp angle, not gently sloped, if your gauge stops at 2.5 " that is your chamber length .
Posted: Fri Oct 10, 2008 5:07 pm
by Researcher
Chamber depth is considered to be the joint between the chamber body itself and the forcing cone, which reduces down to bore diameter. This is loosely based on the length of the "Fired" shell. Today, theoretically when the crimp opens on the shell being fired the end would land at the junction of the chamber and cone. Prior to WW-II many companies had the practice of holding the chamber about 1/8 inch shorter then the shell for which it was intended. Fly in the ointment is nominal measurements often differ from actual ones in both chambers and shells. A very good method I have found of measuring chambers without much outlay of cash, and is quite accurate enough for virtually any situation, is a common 6" flexible machinist's scale which you likely have. Hold the barrels with muzzles toward a light source, not necessarily a concentrated one a window is great, while looking into the breech and the cone will be thrown in a shadow. May have to move the barrels around a little until it is distinct. While still looking into the chamber simply slide the scale in until you observe the end coming flush with the shadow line & mark position of breech end with your thumb. Remove and read the scale. I usually repeat this a few times to insure I am getting a consistent reading, but you will be amazed how accurate this can be done. While I own a Galazan chamber gauge, I use this more often than not. The chamber body itself has a taper of about .005" per inch. Sometimes chambers were cut with slightly worn reamers giving a slight undersize chamber. If the chamber is a bit undersize a gauge made to "industry" standards will not go in to the true depth of the chamber. A.H. Fox Gun Co. shotguns are known for having tight chambers. The machinist’s scale method can be more accurate.
chamber length
Posted: Sat Oct 11, 2008 8:04 am
by terc
Researcher, Thanks for advice.I'll give your method a try this week end.
I'll let you know what I find.
It was nice to finally meet you at the Vintagers this year.
Dave
chamber length
Posted: Sat Oct 11, 2008 3:34 pm
by terc
Researcher, I tried your method to measure chambers.I also used a dial caliper,and as stated before my Galazan gauge. All of the readings are consistently 2 1/2",not a fraction more. I do see the chamber taper when useing the dial caliper. This is an A grade made in 1940.
Thanks again Dave
Posted: Tue Oct 14, 2008 10:35 am
by Calgunner
If the chambers of Philadelphios fox guns are so short, why do 2 3/4" shells drop right is and function operfectly. There is no ragged end on the fired shells to indicate shorter chambers. All spent shells eject smoothly and show no signs of any problems. What gives?
