Used in anger our SAS on tour during the Vietnam war got creative to improve a squads destructiveness they planted a 40mm GL under the SLR combined it with a 30 round mag on the SLR which apparently did the job.
Picture is from my shelves; SAS A Pictorial History Of The AustralianSpecial Air Service 1957 - 1997. By Mick Malone O.A.M(SASR retired) who served in VN with the SAS.