doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Ithaca Flues action bars weak? Which ones?

NIDs are strong, BU. The 10% was discussed by Russ and Greg and it was for the smaller gauges only. I've never looked close due to...well, you know why.

Mr. Rabbit,
Please check your PMs.

No joy, Walt. [?]

jack

Don't recall ever having seen a report of a NID frame failure, of any gauge, here or anywhere else.

Some 40+ yrs ago I bought a field grade 20ga Flues. At the time I knew not of their reputation for cracking frames & it was marked "Smokeless Powder Steel" so for several years it was fed a regular, steady diet of 2½-1 oz loads. gun had 26" bbls marked 2 & 4 with little choke, an obvious cut down, probably from 28". It served me well for those years of use & never cracked. I have often wondered since after finding out about the frame problem, just how much the actual fit of the top bolt on individual guns played in the frame cracking equation. I never checked the fit on that one, perhaps it snugged up nicely & helped support the frame bar.
PS; It weighed an even 6lbs as I recall.

The reason Flues frames crack is excessive operator head space...2 3/4 paper shells in 2 9/16 chambers...plastic 2 3/4 will not crack a Flues frame...Gough Thomas proved this understanding 20 yrs ago...

Robert;
The 20ga Flues I mentioned above had the chambers lengthened to 2 3/4". At the time I was using it was sort of in the transition era & it was shot with both paper & plastic shells. To the best of my recollection about the only shells I ever fed it were the 2½DE-1Oz loads, all in 2 3/4" hulls. I am not very familar with Gough Thomas' works so am unfamilar with the study you reference. Would like to here his reasoning on why plastic will not crack a frame but paper will. You can PM me if you like.

Bob, maybe there is something to support your thinking in Shotguns & Cartridges (a book I don't have), but Garwood's essential conclusion in "danger in case-length" (pp. 260-262, Gough Thomas's Gun Book ) is that Burrard's thinking about long cases in short chambers is faulty in that long cases produce no large increase in pressure in the cones of short-chambered guns unless the long cases simply carry a much heavier charge of shot and powder than do the short; i.e., a charge which the barrels were not designed nor proofed for. Garwood specifically mentions crimped cases but does not mention nor distinguish paper or plastic. One might indeed think that the occlusion in the cones would be greater with relatively thick wall of paper cases and these must have been the ones predominantly or solely available during Burrard's life if not during Garwood's. Garwood is writing in 1964, certainly on the cusps of the adoption of plastic cases. I'd also like to hear more. I'm not familiar with the timeline for the changeover from roll to pie crimp shells altho I'm certainly old enuf to remember when over-the-counter shells were the former.

jack

The one thing absolutely worthy of note here is that Thomas came to precisely the same conclusion as Burrard did. Thomas totally took what Burrard said out of context & applied it in a way not meant. Whether of maliciousness or ignorence I have no way of knowing. Burrard wrote of two different conditions, namely a "True 2 3/4 load" put up in a roll crimped 2 3/4" case & secondly a "True 2½" load" put up in a 2 3/4" fold crimp case. The first he de-nounced for use in a 2½" chambered gun, the 2nd he sanctioned. Thomas took his statements on the 1st & applied them to the 2nd & tried to make it appear he had Discovered some new facts which Burrard did not ubderstand.
After reading this plus his theory that a load using a faster powder would give you less "Felt" recoil because it hit you faster & you had not time to feel it, I mostly lost interest in GG (Garwood Garbage).

Pipes:

Apparently, you've discounted Garwood because of your opinion of the fast slam before the threshold of perception idea. I found it thought-provoking at least and there may be some sound basis in human neuro-physiology; I don't know. I haven't traipsed back thru The Modern Shotgun to discover if your indictment of Garwood is accurate. Quotation is by its nature abstraction from context and can be used to make the other guy appear to say more or less than he did. In the case of the following excerpted by Garwood from Burrard, you be the judge: "It cannot be too strongly emphasized that it is indeed dangerous, in general, to use cartridges whose unloaded caselength exceeds that of the chambers of the gun." [page citation not given] This is clearly not what Garwood thought and if Burrard didn't either (your view)then they are in essential agreement however opportunistic Garwood may have been in using Burrard's argument as an essayist's strawman. I have not found a Garwood argument treating the differential capabilities of plastic or paper case mouths per se to influence chamber pressure as suggested by Bob. C.

jack