Got my revenge against Russian Consulate on Challenging.
I ended up beating this before on WT2 Challenging after running out of ammo at the start on WT4 Challenging. I was about 265 gear rating then, and am 273 now. I did a few loops of the 15 LZ Bosses so I got an Exotic Bullfrog and some good gear pieces, including a classified here and there (though am only using one so far). I already had an Exotic Heel from an introductory cache I opened, but forgot I had it for some time.
I still use the Turret and Seeker Mines, but this time I switched from Recovery Link to Survivor Link. Plus I swapped back and forth between mines and the ammo box at the starting area when the marked enemies come in. It took a long time, but I've yet to build a matched or even partial gear set, nor have I done any recalibrating or rolling. Nothing's maxed, it's just looted parts with looted mods.
The thing about the time was mostly figuring out the best ways to get through each section with what I had. A lot of it is positioning, and knowing when to advance and get aggressive. There were times in a few sections when I died and had to respawn that I worried it would be a very long grind, but then I'd get through it a lot quicker than I anticipated the next try.
Of course good gear and weapons help, along with understanding all the specs and how to put together a build (which I've yet to master), but I also think just knowing what tactics work well when you're playing tough missions is just as important. It can make a mediocre buildless loadout play a lot better than it probably should.
Daily Challenge Complete
https://i.imgur.com/CQXEoxI.jpg
Loadout (didn't use pistol except to shoot their Seeker Mines)
https://i.imgur.com/YIfUbNg.jpg
Gear 1
https://i.imgur.com/JHYL74C.jpg
Gear 2
https://i.imgur.com/1koLc63.jpg
Active Talents (A work in progress getting my Firearms stat up)
https://i.imgur.com/Fvb0iQS.jpg
Hours Played (Just under 147)
https://i.imgur.com/QKWtHVU.jpg