Why are my burgers mushy?
Ok so I need some advice. I've been working periodically on building my ideal home burger over the last several months. I've tried a lot of different combinations of beef cuts and spicing techniques, and while many have tasted great, they've all suffered from the same textural weakness: they're too soft. The patties are so soft that you can barely tell you're biting through meat. I want something with a much more substantial chew.
I've tried cooking them more thoroughly (up to well done), I've tried giving them a thicker crust, I've tried salting at all possible stages of the process, I've tried packing the patties more tightly, but I get pretty much the same texture every time. What do burger places do differently that I'm not doing? Are my burgers too high in fat? Should I replace the chuck in my blends with Sirloin? Any ideas would be appreciated.

I've been to arthur bryants, gates, kc masterpiece, and jack stack in kansas city several times each and jack stack's is my favorite. That sauce is phenomenal.