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Lengthen chambers?

Posted: Sat Nov 15, 2014 7:44 pm
by JNW
I have acquired a 20 gauge Sterlingworth with typical short chambers - 2 3/8". They are 3 weight barrels. I am having some work done on it and asked my gunsmith about lengthening the chambers. He recommended buying 2.5" ammo. I plan on shooting this gun a lot and would really like to shoot 2 3/4" ammo in it. I shoot mostly reloads, much of it 3/4 oz. What do the Fox gurus have to say about lengthening chambers?
Thanks,
Jeff

Re: Lengthen chambers?

Posted: Sat Nov 15, 2014 8:23 pm
by Researcher
In my younger years I had the chambers of the first 20-gauge Sterlingworth I bought lengthened to 2 3/4 inch. I shot quite a few Doves with that gun, mostly using 2 3/4 inch 7/8 ounce AAs both factory and handloads, in the late 1970s and early 80s. Nowadays I keep a good stock of 2 1/2 inch RSTs on hand and haven't had a Fox chamber lengthened in the last three decades.

Re: Lengthen chambers?

Posted: Sun Nov 16, 2014 7:18 am
by Big Friend Ten
I agree with Researcher not to lengthen chambers. That is at least not without making a lot of barrel wall thickness measurements! Most gunsmiths will not have the equipment and knowledge to measure and make the calculations. Then there is the aspect of destroying any collector value of the gun by messing with the chambers.

An alternative to lengthening chambers is to have the forcing cone angle relieved, i.e. lengthen the forcing cones. Note that this still lessens the collector value of the gun but at least if done properly won't put the shooter in any danger. The concept of this is that a sharp angled forcing cone will cause a higher increase in peak pressure than will a forcing cone of a slightly shallower angle. The thin case walls of modern plastic hulls will slip into the shallow forcing cone.

The result from a lengthened forcing cone should be barrel wall thickness NO LESS THAN that of the end of the original chamber. In other words, if the barrel wall thickness at the end of the chamber is .1" then increases to .115" in the original forcing cone, the lengthened forcing cone must not have minimum barrel wall thickness less that .1". Since one never sees a shotgun with barrel struck to look like a sharp angle after the end of the chamber at the forcing cone this can be a safe alternative to lengthening chambers.

Certainly there will be those who disagree... Buy 2.5" RSTs which is great ammunition, load your own 2.5" ammo, or send your barrels to a doublegun smith who will measure twice before he reams! The choice is yours!

Mark

Re: Lengthen chambers?

Posted: Sun Nov 16, 2014 7:58 am
by Stan Hillis
Jeff,

There is a way to reload for short chambers without making major modifications to your reloader. That is by using shortened hulls and the "Hartin crimp". This is very easy to do, if you've never tried it. There was great piece written on it in the Sept./Oct. 2003 Shooting Sportsman magazine.

Polywad also sells a big variety of short and low pressure loadings.

SRH

Re: Lengthen chambers?

Posted: Sun Nov 16, 2014 2:50 pm
by Twice Barrel
The Hartin crimp which allows you to use 2 3/4 inch reloading data is a decent option but I am old school and prefer roll crimping which also allows for the use on 2 3/4 inch data. I have plenty of time so loading speed is not an issue. If you are shooting 3/4 ounce you are probably already reloading anyway so depending on your loader you can get short shell conversions from MEC or PW will make up a short die for their 375 loader.

Re: Lengthen chambers?

Posted: Sun Nov 16, 2014 8:29 pm
by 6pt-sika
I've lengthened the chambers in one gun in my entire life !

Bought a nice medium grade WW Greener when I was 14 years old and had it cut to 2 3/4" . This gun is a boxlock with a tang safety rather then the more traditional Greener side safety . It was choked light IC and extra full when I bought it . Later I had the XF opened up to a modified as well .

Still use that one from time to time . But I think at the moment I have 8 or 9 short chamber guns and I have no inclination to open any of them .

Re: Lengthen chambers?

Posted: Sun Nov 16, 2014 8:35 pm
by 6pt-sika
My previouse post isn't totally true .

My old Krieghoff K-32 I had to have the forcing cones/chambers run out to 3" when they fit it with a set of Kolar sub gauge tubes .

But then that's pretty much standard procedure anytime you tube set any gun be it with Kolar or Briley tubes .

Re: Lengthen chambers?

Posted: Sun Nov 16, 2014 10:54 pm
by JNW
Thanks for the responses. I guess I already knew what the answers would be. I will look at lengthening the forcing cones. I have several other 20 gauges I shoot a lot and to switch over my entire reloading setup will be a huge PITA. Yes, modern 2 1/2" ammo would be great to shoot all the time. At $11 a box I would have to shoot a lot less to afford it and that ain't happening.
Are the outside barrel profiles of early short chambered guns different from later 2 3/4" barrels? Asking if Fox made the barrel walls thicker at the receiver end when they began making the chambers longer.
Regards,
Jeff

Re: Lengthen chambers?

Posted: Mon Nov 17, 2014 12:32 am
by abner
I don't understand all the fuss about not cutting the chambers to 2 3/4", when barrels were return to Fox for repair, if the chambers were not 2 3/4" they cut them to 2 3/4", pressure tested and remarked the barrels. What does that tell you?

Re: Lengthen chambers?

Posted: Mon Nov 17, 2014 1:02 am
by Researcher
.....when barrels were return to Fox for repair, if the chambers were not 2 3/4" they cut them to 2 3/4", pressure tested and remarked the barrels.
That was from the later 1930s onward when a gun was returned to Savage Arms Corp. And, if the barrels didn't pass Savage's proof they were destroyed and Savage would fit a new set at 10% below cost "as a matter of customer good will!!"

Re: Lengthen chambers?

Posted: Mon Nov 17, 2014 7:32 am
by gunut
10% below cost "as a matter of customer good will!!"[/quote]

I usually agree with Researcher but I'm completely lost or confused on this one??....what is this "customer good will" thing....I just can seem to follow? :?

Re: Lengthen chambers?

Posted: Mon Nov 17, 2014 11:20 am
by Researcher
That is from the statement on Savage Arms Corp.'s repair price lists for A.H. Fox shotguns. I misquoted as it is at a net price 25% off the list price for the new barrels. Here is the entire statement from a parts and repair list sent out December 1, 1966 --

Image

Re: Lengthen chambers?

Posted: Mon Nov 17, 2014 11:36 am
by ROMAC
I have an early "B" grade with the chambers lengthened by the factory.

The barrels were marked as such when the chambers were modified.


Image

Re: Lengthen chambers?

Posted: Mon Nov 17, 2014 12:17 pm
by Stan Hillis
Jeff,

Loading shorter shells via the Hartin crimp requires absolutely no changes to your press, set up for 2 3/4" shells. JFYI

SRH

Re: Lengthen chambers?

Posted: Mon Nov 17, 2014 1:11 pm
by gunut
OK got you now....25% below list price....didn't think Savage was giving anything below cost......surprised they even did the 25% off list....the "wont even work on your gun unless you agree to our terms" sounds more like the Savage I know.....