What do you mean by a Vietnam war break rifle........ and cutting it about? I was with 3 Inf Bn's on and off and we never had cut-about rifles. Just bog standard L1A1's and 2's.

Some were camo painted but the general Inf blokes used standard kit. So said, there were rifles used by 'others' with cut short barrels but I never saw one and in any case you were very limited as to just how far you could cut the barrel short. That's because, using standard 7.62mm NATO ammo, cutting past a certain critical length, the operating gas, as all gas does, takes the line of lease resistance and............ anyway, it fails to re-cock! That's why when trials were undertaken to supply 'short' rifles to Malaya, they had to compromise with a short flash eliminator.

MUCH more to it than that of course but shortening barrels and the effects of flash eliminating/eliminators was a regular feature of the weapons design courses at RMCS