Ronald, as long as you aren't in a strict gun law state like new York, California then you certainly can. I live in PA and the most I've bought at one time was 3 but most States don't have a restriction on how many you can buy at one time. Like others have said you can always contact your local FFL dealer to double check but you shouldn't have any issues. Hope this helps.

Ronald, yes you can. Depending on your state, you may not be able to take possession of them all at once. Say you are limited to 1 handgun per month, you can order them all at once, but your FFL will only be able to transfer one every 30 days. Know your state laws, some place require more than 1 handgun purchase at a time to be reported to police/atf...not sure what they would do with the information.

I am a 30+yr gun collector in the southwest US my state of NV has no limits. We like most states have a mandatory background check so you fill out your 4473 on one day and pick up your guns after it passes usually in a day, it is good for 30days. But in that 30 days I can add as much firearms as I want as long as I do not sign off on the original guns I purchased. IE: You have to take possession all at one time within 30 days. Hope I make sense. So I sometimes buy a dozen plus firearms in a year no problem. The most I have ever bought in one order from Buds were 4 handguns and 3 long guns.
Just check your state and local laws or just ask your local FFL and if all is good to go? You can buy as much as you want I know Buds won't complain ; ).

Yes you usually have to notify your local law enforcement agency if you are purchasing more than one firearm at a time

Ronald, yes Sir. Your local FFL Dealer will likely have the most accurate info on your State's firearms laws. Call em up! Cheers and stay safe!

Probably. Have them registered before shipment.