Guns and Firearms in the Philippines
According to the Philippine Law, only natural born filipinos are allowed to carry guns. Means as foreigner you should not even think about it. You would violate the rules and get arrested if you try to carry a gun or other firearms with you. The Philippine law has no exception yet. So you can not buy or carry them legaly.
Some might tell you, that your Filipina wife could buy one and get a permission, Yes that is true, but you are still not allowed to use or carry it.
There are several strict controls for example when you enter your bank or even the Shopping malls and of course at the airports. If they catch you with a gun you'll get arrested.
If you are visiting one of the shooting ranges who have a proper business permit you can fire a gun. If you like shooting games, you should consider to join one of the Airsoft Teams in the Philippines.