I can't swear to this, but back in the bad old days, when I was in Vietnam, several supposedly experienced sorts told me the VC/NVA often fired captured 81mm rounds in their 82mm Soviet/Chinese mortars. Assuming the round would fire at all, I can believe it, because the dinks were seldom concerned with accuracy.
However, in fairness, I should point out that the bad guys owned a number of American mortars, some rumored to have been captured in Korea by the Chinese. The VC/NVA could simply have been firing Ami rounds in Ami mortars.
Down in the Delta we seldom got hit by anything bigger than 60mm (until they started using rockets!). So I can't speak from experience regarding 81/82mm rounds. I can tell you that while a 40mm mortar round will merely dent your average bit of PSP, a 60mm will blow a hole in it. Small hole, to be sure.
Heh. Yep, there was that, as well. I imagine the ARVNs had plenty of our 60s and 81s. Both had been in the arsenal for a long time before VN. I suppose a small VC unit tasked with harassing a base would have trouble carrying anything heavier than a 60. Most of the time it was fire five or six rounds then di-di.
In '68 Dong Tam was a 9th Div artillery base. They had beau coup 4.2" mortars and 105mm howitzers mounted on rafts in the harbor. I can't recall seeing any 155mm stuff other than the howitzers mounted in a tank chassis -- can't recall what their official nonclemature was. We also had a single 8" gun located about a quarter mile off the end of the main runway.
“Perhaps as many as 150 of the lost 105mm howitzers fell into Chinese hands with little or no damage and were not destroyed by subsequent air strikes. The North Koreans had little interest in the American-made artillery when they overran much of the South the previous summer because their Army was a totally Soviet-equipped and supplied force. However, the mainstays of Chinese field artillery in 1950 were Japanese 75mm field guns and 105mm howitzers and guns, Soviet 76mm guns, and the “made in USA” 105mm. For obvious reasons, the Chinese were more than happy to add the captured weapons to their inventory.
An even bigger windfall when the U.S.-equipped Nationalist armies were destroyed, scattered, or defected en masse between 1947 and 1949.50 The exact amount of equipment which fell intact into Communist hands is impossible to pin down, but it is worth noting that so many 105s were harvested from the “running-dog lackies of Yankee imperialism” that the Chinese actually went into the export business. For example, the Viet Minh 351st Heavy Division, a formation patterned along the lines of a Soviet artillery division (and which pummeled the French
garrison at Dien Bien Phu), was equipped with 48 105s.”
Source: Giangreco, D.M. “Korean War Anthology, Artillery in Korea: Massing Fires and Reinventing the Wheel”, United States Army, Command and General Staff College
From Hell In A Very Small Place, Fall Bernard, Da Capo Press, 1960,
"The 351st had come a long way since it's humble beginning in 1945, when the Viet Minh was equipped with some antiquated french and Japanese mountain guns. one by one its battalions had gone through the Communist Chinese training camps at Ching-Hsi and Long chow. At first equipped with mostly American 75-mm. howitzers captured from the Chinese Nationalists, the division received fourty-eight American 105-mm. howitzers in 1953, mostly from captured Korean stocks."(p.126)
Order of Battle: 351st Heavy Division(reinforced):Vu Hien
151st Engineer regiment
237th Heavy Weapons Regiment (40 82-mm. mortars)
45th Artillery Regiment (24 105-mm. howitzers)
675th Artillery Regiment (15 75-mm. pack howitzers and 20 120-mm. mortars)
367th Antiaircraft Regiment ( 20 37-mm. AA guns and 50 .50 caliber AA's)
Field Rocket Unit (12-16 Katyusha rocket launchers)
Further in various actions through primarily the break in morale of ethnic troops fighting on the French side significant amounts of heavy weapons were captured by the Viet Minh and used against their former owners. This included both light and heavy mortars, .50 machine guns and 75.-mm recoiless rifles( again captured in either Korea and Nationalist China). Missed ariel supply enhanced the available ammunition supply of the Viet Minh. Lastly, captured M-24 "General Chaffe" tanks were discovered still in operating condition complete with ammunition as late as 1972 by American Aero Scouts.
If anyone is tired of the demise of the CAR, Hell In A Very Small Place is an excellent chronicle of the destruction of the French Airborne Organization and the costly mistakes of higher command.