Yes, as long as its listed on the MD approved handgun roster. Some examples of approved AR Pistols Ruger-Model Number: 08570 (5.56 NATO), 08571 (350 LEGEND), 08572 (300 BLK), 08573 (5.56 NATO)-------------
Daniel Defense-Model: DDM4 V7 P
Model Number: 02-128-00166 (300 BLK), 02-128-08252 (300 BLK), 02-128-09263 (300 BLK), 02-128-09263-067 (300 BLK), 02-128-16550 (5.56 NATO / 223 REM), 02-128-17050 (223 REM / 5.56 NATO), 02-128-18052 (223 REM / 5.56 NATO), 02-128-19050 (5.56 NATO / 223 REM), 02-128-19050-067 (5.56 NATO / 223 REM), 02-128-19153 (300 BLK), 02-128-19153-067 (300 BLK)
Caliber: 223 Rem, 300 BLK, 5.56 NATO-------------------------
For a full list select manufacturer, then filter by caliber
https://licensingportal.mdsp.maryland.gov/MSPBridgeClient/#/home

As long as the handgun is listed/approved in Maryland Handgun Roster, you can purchase it. Check HERE ( budsgunshop.com/feeds/state_reg/maryland_restrictions.pdf ) and HERE ( https://licensingportal.mdsp.maryland.gov/MSPBridgeClient/#/home ) I hope this helps!