R ib b ent rop ▁P act ▁the ▁Germ ans ▁sold ▁both ▁designs ▁to ▁the ▁Soviet ▁Union . ▁It ' s ▁not ▁entirely ▁clear ▁that ▁Sk oda ▁actually ▁built ▁the ▁weapons ▁itself ▁or ▁merely ▁supplied ▁the ▁blue print s . ▁At ▁any ▁rate , ▁very ▁few ▁weapons ▁seem ▁to ▁have ▁been ▁built ; ▁so ▁few , ▁in ▁fact , ▁that ▁there ' s ▁no ▁record ▁of ▁the ▁Germ ans ▁capt uring ▁any ▁during ▁Operation ▁Bar bar ossa . ▁ ▁It ▁used ▁the ▁same ▁carriage ▁as ▁ 2 1 0 ▁mm ▁gun ▁M 1 9 3 9 ▁( Br - 1 7 ) ▁as ▁well ▁as ▁the ▁same ▁firing ▁platform ▁and ▁control ▁mechanism . ▁It ▁was ▁transport ed ▁in ▁three ▁loads . ▁ ▁It ▁was ▁most ▁fam ously ▁used ▁to ▁defend ▁L ening rad ▁during ▁the ▁Sie ge ▁of ▁L ening rad . ▁The ▁Soviet ▁troops ▁learned ▁that ▁if ▁they ▁fired ▁all ▁of ▁them ▁at ▁the ▁same ▁time ▁and ▁used ▁high - expl os ive ▁shell s , ▁when ▁the ▁r ounds ▁expl oded ▁at ▁the ▁same ▁time , ▁they ▁would ▁f lip ▁over ▁adv ancing ▁German ▁t anks . ▁ ▁References ▁▁ ▁Category : World ▁War ▁II ▁art illery ▁of ▁the ▁Soviet ▁Union ▁Category : 3 0 5 ▁mm ▁art illery ▁Category : Art illery ▁of ▁Czech oslov ak ia ▁Category : S ie ge ▁art illery ▁Category : How itz ers ▁of ▁the ▁Soviet ▁Union ▁Category : C zech oslov ak ia – S ov iet ▁Union ▁relations ▁Category : World ▁War