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

The Flues action bar is frequently cited as being weak, thin-walled, too much material plowed out to make room for the gadgetry, not enuf beam section in the water table. Replaced by the much sturdier NID. I've seen too many woozy-loose field-grade NIDs to think this is absolutely the case but haven't seen either Flues or NID with a cracked bar. Question: Does the bar on the Flues SBT share the deficient engineering with that of the doublegun. What got me wondering is the filing of the root of the angle between water table and breech wall on the SBT to an absolute sharp corner (no radius). Everyone with the slightest experience of bending fatigue recognizes this as a stress riser, both today and in the heyday of the double. In fact, the Flues doubles don't have the sharp corner. Anything suspect about the trapguns? I'm using 7800psi, 1 oz. reloads in the one I recently purchased. Too much of a looker (the gun not me) to take chances.

jack

Greg Tag's the one who's kept track of Flues frame failures, and he'll probably be along shortly. But if I recall correctly, most of those reported have been on 20ga guns, some of which were made very light.

Thanks Larry. I believe KYJon said the same thing recently in ref. to the 20s. Light barrels also. I expect Mssrs. Taggart or Snyder will know when they get back from their barbeques.

jack

The SBTs should do fine.

Every cracked Flues that I have seen has been a 20. Sure that there are others out there, that I have not seen, but the 8-10 that I have seen have all been in 20 only.

It has been suggested here that the width of the 20 along with the thickness could be an indicator of possible light weight construction and therefore potential problems.

I rather think that the real problem is modern loads in a gun not design for the high pressures. If your gun is designed to handle 8-9,000psi and you feed it 10-12,000psi be happy the water tables fails before the barrels burst. A crack is a bummer but a ruptured barrel can ruin you future, your future shooting and possible the number you can count to on your fingers.

The caution about the thin 20 barrels is about not having the chambers cut to 2 3/4" as the amount of metal in the chamber areas can be marginal when done. This just encourages shooting high pressure shells, with now thinner barrels and only bad thing happen if a barrel fails in the chamber area.

The sub gauges are the ones suspect. 20's, 16's. They vary in dimension but as many as 10% of these are found with cracks. Fortunately, they are butt ugly so no great loss.

Thanks to all. I think I'm on safe ground. Could stand to take a smidge off the cheekpiece but I probably won't as so far I'm shooting my usual 19-21.

jack

Here you go

Hmmmm ????? 10%,??? Pete, I assume you have kept serial numbers so we can share this info. This is the first I have heard of the 10% failure, and over 35 years, I have seen little of this. I guess I must have been lucky.

Hmmmmm again.

So the 20 gauge Flues may have a problem, but I'm not sure even after re-reading the previous posts whether or not that problem also pertains to the 20 gauge NIDs.

Weren't the NIDs built with a beefer receiver in response to this problem?

As a side note, the elderly gentleman I got my NID from stopped me a couple of weeks ago and said he had found some 2 1/2" shells I could have. I chatted with him for a while, thanked him again, and it was only after I got home that I looked at the partial box of shells he had given me. They were 2 1/2 Dram, 1 oz loads he had been shooting. Not 2 1/2" inch. Certainly a heavier load than I would have ever used but the gun appears none the worse for it.

Will increasing the chamber length to 2 3/4" leave the barrels of my 20 gauge NID possibly too weak?

Regards,

Dan