The first one blew up on a 20” 7max Sherman shooting 180’s at 2730fps. In load development. Never found any of the other part of it.
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The second one was on a 24” 7wsm with 180’s at 2815fps. This was all I found of the rest of it.
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Just to be clear these are 2 different SN can failures.
The scythe I just picked up yesterday has baby welds compared to these don’t really have high hopes for it.
Thank you for sharing the pictures. Zooming in on the pictures the weld convexity is evident. It does look like the pictures of the individual pieces that the edges of the weld (the toe) are underfilled and/or undercut.
Note in the pictures the entire weld is still visible, it is at the edge of the weld (the toe), and not the weld itself, where the fracture occurred.
I wrote on post #1,333 of this thread issues with larger welds. If what we are seeing in these pictures is underfill/undercut, it would create a greater stress riser than an oversize weld. An underfilled/undercut weld toe would be the thinnest cross-sectional area.
What APPEARS to be here the convex weld would be thicker and stiffer than any other cross-section of the suppressor, so it is not going to flex or give at all compared to the rest of the suppressor as forces are applied. Then there is the suppressor general wall thickness where most of the flex/give would occur; if the weld was the same thickness with little to no convexity, then both the weld and the general suppressor areas would flex equally. If there is underfill/undercut, then the vast majority of all flexing, expansion, contraction, stretching, etc. would occur in this very small area eventually leading to a failure.
I am stressing IF. These are only pictures and are subject to interpretation of a two-dimensional photo. Without the part in hand, and at a minimum a caliper to perform measurements, it is just a speculation. A finite element analysis would pinpoint where localized stress occurs, especially if underfill/undercut would be purposely introduced to see how significantly this discontinuity could create issues leading to failures.
This was my job (now retired) in industry to administer and exam weld test, to create, analyze in-work welding procedures, to recommend changes to areas where failures occurred, and to anticipate, adjust, and improved weld joints, procedures, techniques, and design to prevent possible failures.
My first thought, if there is indeed underfill/undercut occurring, is to induce weld puddle agitation. This would/should increase the weld width slightly, decrease weld convexity, and reduce any underfill or undercut at the weld toes. This may be something already corrected, and why the welds in the pictures of the Scythe suppresser in post #1,323 are wider than an earlier production of the Scythe.
