 Nyorai kupfuurira kweiyi ndima - Muna 1977 na1978, Bull akaronga kutengeswa zvisiri pamutemo kwe30 000 155mm artillery shells, pfuti dzepfuti nemapurani eGC-45 howitzer pamwe chete nemidziyo yeradar kuArmscor, sangano rezvombo reSouth Africa; nekutakura kuviri kwakaitwa kuburikidza neAntigua muna 1978 uye imwe kuburikidza neSpain muna 1979. Hondo yeSouth African Defence Force yezvombo zvekare zvemahowitzers zvakapera basa nekurambidzwa kwekutengeswa kwezvombo zvakapfuurwa neBM-21 Grads panguva ye Operation Savannah muna 1975. Kuti vadzivise zvombo zvemazuva ano zveSoviet zvakapinzwa muAngola yakavakidzana nayo, vakuru vakuru veSouth Africa vakatanga kutsvaka zvombo zvemazuva ano uye vakatumirwa kuSRC. Armscor akaedza GC-45 pamwe itsva kugadzwa kubvumira kuti yakawedzera upfu mitoro uye akagadza ebetsero simba chikwata kuvandudza mufambo mumunda. Howitzer yeG5 yakabva pairi yaikosha zvikuru kuhondo dzokuSouth Africa dzokurwisa mauto okuCuba muAngola, chichivabvumira kunanga zvivako zvehurumende nevashandi nokururama kunoshamisa. Mukuwedzera, kutumira kwekukurumidzira kwaivewo nechinangwa chekugadzirisa kushomeka kwakanyanya kwemapurisa emapurisa nekuda kwekupinda kwavo muAngola. 