Hi Tracy and welcome. Yes, no issue with purchasing 2 AR style rifles in MD. Just make sure to select the required Heavy Barrel AR's to be compliant in MD. Details under Rifles here: budsgunshop.com/feeds/state_reg/maryland_restrictions.pdf --------- Cheers, stay safe and enjoy!

Hi Tracy, AR rifles are regulated firearms in MD and you can only purchase 1 every 30 days.
You can purchase 2 rifles at the same time if they are not regulated.
List of regulated firearms here >>> https://mdsp.maryland.gov/Organization/Documents/2014RegulatedFirearms.pdf
Stay safe & have a great day!