I've had some bad luck with ACS bits recently -- they just didn't cut stainless very well; don't know who the original mfgr was. I think Avery sourced their drills from Pan American tool (VAF advertiser); I bought a bunch from them recently and am very happy. Pan American only sells in multiples of 12; great for #30 and #40, not so great for the less used sizes.
 
Another vote for Pan American. The price and quality are right on and the double margin bits make for a perfect round hole, pretty much reamer quality. They do have a minimum order($50) though so stock up!
 
Guhring Series 659 from MSC

I recently needed to drill sixty 13/64" holes (.203) through 1/4" 304 SS bars (not aircraft related). A friend who owns a CNC machine shop highly recommended Guhring Series 659 cobalt, TiN coated stubby drill bits. I bought two of those online from MSC INDUSTRIAL SUPPLY and they were fantastic. No pilot hole required and they went through the stainless like a hot knife through butter. (I used my drill press and sprayed soluble oil coolant.) I never needed to use the second bit. If you don't mind paying $12 each (plus shipping), these are probably the best drill bits for stainless you can buy. https://www.mscdirect.com/product/details/00395962
 
I've gotten some poor quality drill bits from Cleaveland, excellent drill bits from gen-av-hardware, and good ones from The Yard Store.

Dave
 
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