The one thing you didn't mention was the height of the fences where the cross unders are that you have snares set on, then if I remember correctly from past conversations you aren't snaring these for for a fur market situation but predator control or the length of the snare your using now.
So I'd like to suggest this not knowing these details, I'd go with longer snares let's say 4-6' so they can jump the fence and tangle in it instead of a kill pole if fur damage isn't a concern.
Trail snare sets are still productive when sheep aren't in the same pasture with a 5-6" loop 6-8" off the ground just because of how a fox travels generally with its tail up or at least this has been my experience with them here in Montana.
Also are the snare locks new or have they been used before ? The lock may have a little wear so the don't lock up as they possibly could and the 1x19 cable is inherently slick in it's own right so the 7x7 cable may work better in your application even if the snare loop isn't a picture perfect circle loop then a crossed set of kill poles could be beneficial with a space between them.
I hope this helps ! Stay Safe out there and enjoy your day !
Allan
hi yeh no fur trade hear just knocking numbers down for a land owner, the fences are just your normal stock fences maybe 4 inch squares and 3 ft 6 high with 2 strands of barbed wire on top,, most my snares are 4-ft long and I anchor about 2 ft off the floor as solid as I can to try catch them under the chin and behind the ears, NORMALY this with the fast 1 16th cable this is a pretty deadly set up I can and have taken 3-4 fox a week of the same set with very little damage to the run...
like I said I set so they get wrapped up in the fence and hang them self real quick, but just lately they have been doing that and twisting the wire off.
locks are new and a few used but we cant used locking snares hear anyhow hence the micro lock and the black dogs their sold as relaxing so it keeps me right on that front..
I did forget to say one massive reason ive stuck to the thinner cable is badgers! if we get caught with one in a wire then were in some serious hot water! even as a accidental catch but they (so I hear!) will make short work of the 1 16th wire and pretty much walk out of it