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

Thanks, Rich.

Miller, my post as written might be confusing to some, so for clarifiction my use of the term 'R scale' was in ref to 'Rockwell' rather than to any specific scale. If I read Rich's post correctly, he stated that the angle machined 'hard'. That would have much more to do with the 'feel' and be below the likely penetration of the case hardening, at least to my understanding of both machining language & case hardening. My understanding is that case hardening in excess of .010 inch penetration is both difficult and unlikely on the mild steels that were typically used for actions. And since this action is now sectioned it will be very easy to take a hardness reading below the case as well as through it in the area of the frame angle and in other places, like the main body or the water table. I think Rich's observation may shed a bit more light on why some of those small gauge Flues actions failed, aside from just being small, and thin in that area.

FWIW, my main bud often shot a 28ga. 1 & 1/2 grade Flues with normal modern loads, inclusive of a few 1oz nasty blasters, for 20+ years before selling it. I have no idea how many modern rounds went through it in that time frame, but numbers of flats anyway. It never showed any issues from the experience in spite of not being designed with modern ammunition in mind. Good practice? NO. Did it crack the frame or have other issues? NO. Perhaps it was not so 'hard' at the angle? I don't know.

To Jack's original question: I have seen SBT's that have been shot seemingly a jillion rounds and have never heard of one breaking a frame. Lotsa hoopla about them being much better after serial # 400K, but used to see plenty of the older versions w/#'s well below that at shoots where they were being used & still shooting. I suspect many got rebuilt like today's P-guns as they needed it &/or as parts wore or ultimately broke, but I have never heard of any frame issues. BT-99's in the early 70's allowed many to retire thier older I-guns and also the I -SBT's became quite collectable. They were never inexpensive. The last new that one I saw for sale was $1800 and that was, what?, close to 40 years ago, now.

TW;
Yes I understood the R simply referred to Rockwell. I was not intending any contradiction to your post, just additional info. The Rockwell C scale is most commonly used for checking the hardness of heat-treated steel. On case hardened steel one might not get a correct reading using the C-Scale. Many small machine shops are set up to check the common C scale so was just a warning if someone had access to one, it might not be adequate. The Rockwell C tester operates by applying a known load to a diamond pyramid shaped penertrator. The machine reads the depth of penertration & converts it to a hardness number. The problem with thin cases is the penertrator will likely break through the "Case" & read much softer than it really is. If you get a reading in the low C30's but a file won't cut the case, you can bet you didn't read the actual hardness of the case.

The way this action is milled you can get a reading at diff. depths of the metal and compare them. A reading from .030 below the surface should be softer than on the surface. Still trying to get it tested, haven't got an answer yet.
Rich

Well, better looking than a Knick anyway. Been down some byways and ridden some hobby horses on this one. Getting back to what actually inspired me to ask, I didn't really think a trap gun would suffer from the same malady as an anemic smallbore albeit made in the same town by the same folks. What I thought was: Look at this sharp root in the angle between standing breech and flats; what's that about? Yep there was a balloon over my head encapsulating those very words. Nobody knows I guess like nobody knows why the NID needs cocking indies in 1925. Zany bunch those upstate "Greeks". }:-[

jack

Well, better looking than a Knick anyway. Been down some byways and ridden some hobby horses on this one. Getting back to what actually inspired me to ask, I didn't really think a trap gun would suffer from the same malady as an anemic smallbore albeit made in the same town by the same folks. What I thought was: Look at this sharp root in the angle between standing breech and flats; what's that about? Yep there was a balloon over my head encapsulating those very words. Nobody knows I guess like nobody knows why the NID needs cocking indies in 1925. Zany bunch those upstate "Greeks". }:-[

jack

Just dawned on me when i looked at the action on the first page of this post that i have seen three actions (4 with the one on first page) cracked in my life, all on the right side, all running in the same direction. Inside the action the cracks run along the thin part of the action where it meets the heaviest part of the action. kind of hard to explain with out looking at the action with cutout. Maybe to late at night for my tired old brain.