How can I stop my burgers from shrinking?

I like burgers that fit the buns, but my burgers always shrink and I don't always have time to make smaller buns.

I use typical 80/20 ground beef with a little salt and pepper. I tried making them bigger so they shrink down, but making them by hand is time consuming and the biggest hamburger makers I have found are only 4". Does anyone have any ideas on how to either stop the burger from shrinking? Or a large hamburger maker? Or something I have not thought of?

Try putting a divot in the center of the patty the size of the bottom of a shot glass.

Hi Matt;
How large (weight) are your burgers?
We buy Kyser rolls (1/3 larger) than standard burger buns.
I make 1/2# burgers, and sometimes they are too large after cooking and hang out of the bun.
The burger is 80/20, just like yours, and comes from a small, reliable butcher.