doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Ithaca 20ga Flues

KY Jon,

Reference to the Ithaca. I have a 20 ga Flues that also has thin walls (.018"/.020") and shows no sign of honing or outside work. Did you shoot yours? If so, what loads?

John

John: Jon could give much better advice if you could share where, exactly, is the barrel MWT .018", and if the barrels are fluid steel or pattern welded.

Every vintage Bulk or "Progressive Burning" smokeless pressure-distance curve shows the pressure to be less than 1500 psi at 20"; modern Dense less than 1000 psi.

This is 12g 1 1/8 oz at 1200 fps from the Alliant site

I shot them a lot. All reloads in 7k range. I trimmed down 2 3/4� hulls to 2 1/2. Loaded them to 1100-1150 FPS. If you want I�ll pm them to you. I hate posting reload information because people seem to think they can make minor substitutions without having major impacts on the loads. Worse half reloaded I know don�t even own a set of scales to check things. No excuse for that except being lazy or stupid. Never trust charts to tell you what your machine drops.

Get 6� past my fingers and I don�t care if it�s .020 or less. I like my fingers. Anything inside my hand grip has to be better than that thickness.

Drew & KY Jon,

They are fluid steel. Minimum dimensions start 8-9 inches forward of the breechface and run consistent to the chokes. Bores measure .615"/.616 just forward of forcing cones and just before chokes. 28" Mod & Full. 2-1/2" chambers. Weight is 5lb-9oz.

Ky Jon,
I don't reload any shot shells anymore. I have reloaded for rifles since 1976 and still have all my equipment. I was heavy into benchrest shooting and KNOW the finesse involved. I have flats of 2-1/2" Polywad Vintagers in 20, 16, and 12 ga and also 2-3/4" Win AA low recoil/pressure in 12 & 20 ga. But I have never had another gun with tubes this thin.

John

Recently this year I bought a pair of 12 ga Specialty barrels that someone had them sent and bored for thin wall choke tubes.
I always measure barrels for bore and the right one was .725, the left was .730 which is normal for L.C. Smiths after 1913. Now using the choke tubes you have to figure in the .005 difference for choke.

Speaking of bore gages, I use a Skeet's for 10 ga., 12 ga. and 16 ga. I made a ring for the 16 ga. that is .600, since most of the L.C. Smith's before the 1930's were .650 bore.
I had some trouble when I first bought this on eBay, someone had messed with it and I called Skeet's and talked with Dean and he said send it and he would fix it. At the time he had made up some special length (17") for Midway (a guess) and he did put one on mine and replaced the dial indicator for I think $30 and I think that included shipping.
My original was like a bakelite, brown in color, tube, this one is aluminum.

John: by anyone's recommendations, less than .020" at 8" is inadequate, and extremely unlikely to have left Ithaca that way.

Even CIP MWT for �Standard Steel� (Non-alloy AISI 1045) with tensile strength = 101,526-123,137 psi for 20g at 8" is .041"
https://docs.google.com/document/d/1ZIo0y746UsSRZIgRuuxwAbZjSBHitO_EanvwLYc-kGA/edit

Walt Snyder graciously shared a 1919 Ithaca Gun Co. letter from A.P. Curtis, General Manager requested tensile strength testing on a section �cut from a barrel made in Belgium� to be performed by E.J. Stormer of Racine, Wisconsin. The letter did not indicate if the barrels were �Smokeless Powder Steel� used on the Field grade, �Fluid Steel� or �Nitro Steel� used on the No. 1 and No. 1 1/2, or Cockerill Steel used on the No. 1 Special (discontinued that year).
Tensile strength was reported to be �about 70,000� psi. Composition was similar to AISI 1030.

Another careful evaluation might be in order

Concerning Flues 20's, there's another area of concern in addition to the barrels. On the very lightweight guns, some have suffered cracked frames where the water table meets the standing breech. Years back, we had a member (Greg Tag) who was keeping track of Flues failures. (The only ones I recall were 20ga guns.) In at least one case I recall, the owner apparently shot some of the "light" big box special target loads . . . which are OK in terms of shot charge (7/8 oz), but perhaps not pressure and/or velocity. I don't remember whether the gun in question still had its factory short chambers or whether they'd been lengthened. But if still short, then those factory 2 3/4" hulls would have resulted in additional pressure increase, perhaps additional recoil, etc. Anyhow, the frame was specifically identified as a possible weak point on those earlier and very light 20's (per the earlier post), and it would have been a very bad idea to shoot standard American factory ammo in those guns. 2 1/2" RST's or European factory loads to CIP pressure standards would be the way to go. But obvious from the weights listed that all Flues 20's are not equal in that respect.

Easy fix Larry and this is a 12g that appears just a tad off-face also

.018 at 8� is way too thin for me. Are you sure about those measurements? 14-16� + maybe but not at 8��s. My hand is there or within a couple inches. Heck my face is too close.