[jameskmonger]

pawn Code:

new gunname[45];
if(!sscanf(params, "s[45]", gunname)) {
    for(new g; g < sizeof(WeaponName); g++) {
        if(strcmp(gunname, WeaponName[g], true)) {
            for(new p; p < GetMaxPlayers(); p++) {
                 if(IsPlayerConnected(p)) {
                     GivePlayerWeapon(playerid, g, 99999);
                 }
             }
        }
    }
}

You can implement it into a command.