What a great informative post fellas. Great info for the new martin trapper. If I were him I would ditch the goose hunt and trap the martin, weather permitting......jk

I would call Keith or Humphry at sterling fur and just order the springs. Sure they have several hundred lying around!

I trapped southeast Alaska for about 35 years and certainly couldn't count how many marten I caught over the years. 100s, anyway. I have taken them with small longsprings, 110s 120s, and even much larger traps set for wolverine and wolves, not to mention the odd few setting off 280s set for otter.
Early on I started trapping them, and mink, with 110s. I found several marten and large male mink still breathing with those traps, including traps using elevated vertical flowerpot sets with the trap secured to a tree or limb. One was even clinging to the tree bark, taking a breath every 10 seconds or so. I was snowshoeing that line and assumed I had just caught that marten and that it would succumb to the trap shortly, so I continued up the line and would retrieve it on the way back.
About 3 hours later, I arrived back at the set only to find the marten still clinging to the tree and still gasping.
That was it. I ordered several dozen Belisle 120s, retired the 110s, and never looked back.
I also evolved my techniques over the years, rarely using flowerpots, and very few vertical sets, mostly relying on leaning and horizontal poles and boxes, ALWAYS in such a way that keeps the dead marten off the ground.
I also went to about 90% wood pedals for both marten and mink, which reduced refusals to nearly none, and almost always either a neck strike or perfect suitcase.