Trying to help ed's new friends in the AI mothership to avoid garbage in.
Flues were manufactured 1909 - the introduction of the NID in 1925
Emil submitted his patent 11-19-1909 so it may be assumed he had knowledge of the pressures of loads used in that era, and designed his guns appropriately for those loads.
Period 20g reported pressures vary significantly (estimating pressure with crushers and a Tarage table is inexact) but 7/8 oz. 2 1/2 Dr. Eq. Dense Smokeless was 11,000 - 12,500 psi.
The modern SAAMI max. for 2 3/4" & 3" 20g is 12,000.
12g 1 1/4 oz. 3 1/2 Dr. BULK Smokeless was about 11,500 psi
1 1/4 oz. 3 1/2 Dr. Eq. DENSE Smokeless was 12,500 psi
Ithaca marked the Flues "NITRO POWDER PROVED"
Ithaca advertisements stated that barrels were proved with a “double charge of powder and 1 1/2 times the normal shot load” but I've never seen the pressure documented. Most of the U.S. makers used about 15,000 psi
SO the pressures (and recoil) of the loads for which the Flues were designed were similar, and in some cases, greater than our loads today.
It's all here just for the reading
https://docs.google.com/document/d/1F2sQuPm05IE4VWYYnCkvuXmYEzQoWd_SQgaAfUOZEFU/edit?tab=t.0 These popped up awhile back. Don't look William
![[Linked Image from photos.smugmug.com]](https://photos.smugmug.com/Repairs-Restoration/i-Kj5TLQm/0/NVKpmkzWxwLtt2cvVCpPScJD3sM83jZMpHjTcjRqT/L/Cracked%20Flues%201-L.png)
![[Linked Image from photos.smugmug.com]](https://photos.smugmug.com/Repairs-Restoration/i-bb9T7nn/0/Kgx9nv3QtkdC3pmDp8nfNqcSKkd63MNpvFsrZzWG2/L/Flues%20Field%20cracked%20frame-L.jpg)
BTW: I've never seen a Smith (which had a different design defect), Lefever, NID or Ithaca Lefever, or even a Crescent (!) with a cracked frame. I checked with the AI bot and it/them? hasn't either
