I'm in Maryland and I went through this trying to get a SA XD-M Elite OSP....
They only come with Mags Greater than 10 rnds.....
You can't buy >10rnd magazines in MD, but you can possess them and it is legal to purchase them out of state and bring them into the state with you....
The problem comes when the Firearm you want only comes with >10rnd Magazines....
As long as you don't receive > 10 rnds magazines in the purchase, you are legal, that is you receiving them, not the gun shop or FFL...
Maryland Law allows the FFL to bring the Magazines into compliance....
Either pin them or install blocks in the magazine to limit it to 10 rnds or less, or simply take the magazines out of the package and dispose of them....
Or get whomever is sending the pistol to remove the magazines from the package before shipping.
Most online retailers won't bother with it and will simply refuse to ship to Maryland, refuse to open and remove things from the package.....
Ask your favorite gun shop if they can get if from their supplier. If their supplier has it in stock, in Maryland they will ship it to the gun shop and the FFL will have to fix the magazine issue. Either pin/block or get rid of them.
Then you can drive over the closest border to the gun shop there and buy full capacity magazines.