Sondra points to makes even futher note of:
Gents, thanks for a fine article. However, with regard to weaponry coming from the US, please be advised that Rocket Propelled Grenades (RPGs) used by the Cartels are made in the PRC and former Combloc countries and not in the USA.
Also the grenades found in the US coming from Mexico are of Chinese or Combloc origin. many of the small arms, like fully automatic AK-47s are illegal in the USA and come from China or former Combloc nations. They should not be confused with the semi-auto look-alike weapons made and sold in the USA which are of no use to the Cartels as they are not machine guns. They are merely ugly like their military ancestors but are no different in action than a semi-auto hunting rifle sold at Big-5 or Oshman's and of far less power.
Fully automatic M16s, while made in the USA (or abroad under license) are military weapons sold to approved by State Dept. military units and governments abroad, then stolen and smuggled in to Mexico and elsewhere. Automatic weapons are not available in the USA over the counter and require paperwork, background checks, huge fees and approval and subsequent regular inspections of the privately-owned arm by BATF. BATF has not reported thefts or loss of personally owned Class III (Full auto selective fire). BATF should be able to provide you back-trace information proving that the weapons seized in Mexico, while made here or abroad under license, were stolen from the end-user, illegally acquired and smuggled in to Mexico by the Cartels from elsewhere than the US.
Which last would require the Mexican government to give us the serial numbers of the stuff they claim were legally bought in the US and smuggled to Mexico, and for some reason they don't want to do that...