the trap is set within a clean run,so with having all that steel exposed to the mole , you gotta be extra careful about contaminating the traps with forign smells ,the trap roof is then covered in loose soil and i like to put a bit of pressure on either side of the springs/trigger mechanism to stabalise the trap(difficult to explain)
it was an old idea in this country that the trap had to smell of moles , thats crap, i want my traps to smell of nothing but soil , so that when a mole comes along his run , he is in the trap before he knows something is amiss, which is another reason i prefer to set traps in older established runs rather than new workings, i believe the mole is travelling faster in the older runs to get to the newer worked area,s
i have tried setting the half barrel similar to how the out o sight is set , with loose soil in the run , didn,t work for me , i think the springs are not powerful enuff to strike thru the soil fast enuff to get a good catch and kill swiftly, there is a trap overhere caller a talpex , i have had a bit of success setting them exactly as you do the out o sight, handy in very loose soil , i still prefer the half barrel
i,m hopeing to be able to put up pictures soon and will be able to explain better with them

SnipperBBB the spring loaded door would I believe stop the door raising and probing. I know what you are describing and have used that method on certain squirrel excluders to discourage entry or routeing into an area not desired.

I have found tieing something as simple as two gum bands on the bottom of either side of the door will provide adequate tension Or a bent flat metal spring placed on top of the door attached to the ceiling of the trap body would work also. Just havent worked that much beyond this point since it worked quite well without too many modifications.