Baltimore’s Piper & Marbury would catapult itself close into the ranks of Washington’s 20 biggest firms if its current merger talks with Chicago’s Rudnick & Wolfe come to fruition.

A combination would boost Piper’s D.C. office to 155 lawyers, nearly as large as such homegrown mainstays as Williams & Connolly and Finnegan, Henderson, Farabow, Garrett & Dunner.