When you pay someone via Paypal as gift, you have no protection. Paypal as gift means no goods should be exchanged, and as such, Paypal will not help you should anything go wrong, paypal gifts are completely non-refundable under any circumstance.
Sellers asking for Paypal as gift, you are also just as vulnerable as anyone paying you can issue a charge back if they send the funds via debit card, even after you have sent the goods they can still issue a charge back.
If you buy an airgun and pay via paypal you can not involve Paypal in any dispute as an airgun is a 'restricted' item in their eyes.
So be aware using Paypal as gift offers no protection for the buyer or seller!