The Unofficial P64 Resource Forum

Well, according to the friendly voice that answered the phone when I called Mag-na-port International up there in Michigan, a blowback-operated pistol with the recoil spring around the barrel is not suitable for porting. So, onwards with other ways and means to tame the recoil.

makes since now that you mention it, maybe it could be fitted with an barrel extension?

You might buy an extended ported barrel. Federal Arms made them with a 4 1/2" ported barrel.