Super Fox HE with 2.5" chambers?

[Jawjadawg]

Seems a little odd. How would that happen, and for what purpose?

[charlie cleveland]

some things is a miss here..i dont see nothing super about a 2 1/2 inch chambered gun... charlie

[Researcher]

How are you measuring the chamber? Super-Fox chambers are notoriously tight to assure the shell is perfectly centered to the bore, and hence many chamber gauges don't go in all the way to the break from the chamber to forcing cone.

[Cold Spring]

Deleted, sorry.

[Bill Murphy]

I assume that a nominal 2 3/4" chamber would actually measure 2 5/8" as was common at the time. A tight 2 5/8" chamber may measure less than that with some chamber gauges. The only way to tell when the chamber actually starts is by watching a bore micrometer as it enters the forcing cone. Unfortunately, most 12 gauge bore micrometers will not extend to the diameter of a 12 gauge chamber. The alternative is to view a machinist's scale as it enters the forcing cone, a difficult process, but possible. I would like to hear Frank Srebro's take on this, since he has measured a bunch of HE Fox chambers.

[Cold Spring]

I wouldn't be surprised if the Super-Fox in question is one that's currently on one of the on line auction sites. Just looking at the pics there, I don't see the proprietary Fox 3 IN chamber stamp, and without doing a record card check a reasonable assumption is, that S-F was/is chambered for 2-3/4" shells. Super-Fox chambers were "cut tight" to center the shells and allow a repeatable transition of the shot and wads into the forcing cone and bore. Using a standard chamber gauge, these S-F 2-3/4" chambers often appear to measure about 2-1/2". Personally I've never had good luck using the machinist scale method on Supers. It's very hard for me to feel the transition from the front of the chamber into the forcing cone. Others have reported it's worked for them, so what can I say?

I'm particulary interested in Supers with 3-inch chambers and have done a bunch of cerrosafe casting of said chambers on original guns. That led me to getting a some special gauges made to match the Fox chamber diameters and taper - which were not industry standard at the time. I usually have these gauges with me at shoots and am more than happy to measure Supers with 3-inch chambers to confirm or deny they are factory. I've seen many factory 2-3/4 and even 3 IN Super-Foxes that were redone with modern type 3-inch chamber reamers and they will measure overdiameter as compared with the special Super-Fox factory 3 IN chamber. Why rechamber a Fox factory 3 IN chamber? To make it easier to load with some 3-inch paper shells back in the day. To complicate things, most but not all 3-inch Fox factory chambered Supers are stamped 3 IN. In fact I measured two last year at Hausmanns that were not stamped 3 IN but were absolutely original-chambered. But two months before I measured two other Supers at Chuck's shoot at Blue Ridge that had more-less modern "sloppy" 3-inch chambers. Sometimes it's better not to know. Sorry for the long diatribe.

PS: I don't charge a fee to measure 3 IN Supers with my gauges but you will owe me a cigar or soft drink, etc.

Frank

[Jawjadawg]

Frank,

Thanks for the "diatribe". That's very helpful. You are correct regarding the gun in question.

Will

[David Noble]

The proper way to use the machinists scale to measure the chamber is to hold the barrels up to light while sliding the scale into the chamber, keeping the scale flat against the chamber wall. When the end of the chamber is reached the scale will lift as it enters the forcing cone allowing light to be seen beneath its edge. With practice this method will allow extremely close measurement of the chamber length.

[Bill Murphy]

I just look at the scale as it approaches the shadow. When it touches the shadow, I attempt to take a measurement. Will, I hope you are the lucky buyer.

[AmarilloMike]

I also measure chamber lengths with my wall thickness gauge. There is a sudden and noticeable change of wall thickness at the end of most chambers.

I have a tuning fork type wall thickness gauge.