I use to be a machinist, it's been a while, but I'll attempt to help out here.
First let's start with what you did durring your first attemt that didn't work out for you. Can you be specific? What type of machine are you using, Mill or Lathe? What's the nature of the cut are you skimming the faces square or are you cutting a t-slot? What type of carbide tool are you using? An endmill, insert cutter, boring bar, try to be as specific as possible.
Now the material, I'll assume 7-16 refers to the chrome and nickel content in the stainless. I didn't find too much on it doing a quick goodle search. If has more nickle than 316, which should make it harder (I think). If it's anything like Incolnel, which I think is just a brand name for 718, it's going to be a pain unless you have the right equipment. READ RIDGED TOOLS.
I have lot's of experience w/ Incolnel 718. It's HARD and "gummy", take small bites at a high cutting speed and use LOTS of coolant. Interupted cuts will be very tough, so avoid them if you can. It will wear tooling fast, and once the tip is gone, you'll loose the tool and the piece if you don't get out of the cut ASAP. So, change tools often and keep them COOL. When I left the shop, we had just started experimenting with ceramic inserts, which held up much better and longer, but still need to be checked and replaced frequently. And again, interuped cuts with this material are hard on inserts especailly ceramic, which is even more brittle than the carbide.
Give me some more specifics and I'll see if i can't help more. It's been about 7 years or so since I did this type of work, but it was all i did for about 5 years or so. Hopefully I can push some of that knowledge on!