Early M16 rifles being used in Viet Nam

[Peter Laidler]

During our very basic (basic, but 3 years basic......) traninig as UK armourers, barrel shortening was always a discussion point. Later on, when you became more proficient, a the RMCS, Shrivenham, we would cut barrels shorter for various tests. After an inch or so, the accuracy would drop off and shortly after that, functioning of the rifle became highly problematical due to what we called volumetric pressure or loading.

I wrote it all up a few years ago, relating to L1A1's and Brens. Shortened barrels.......... A bit like mickey mouse watches. They look good, but they ain't much good for tellin' the time! Just my experience of coutse

[browningautorifle]

volumetric pressure

Then they have to go in with numbered/lettered drill bits to increase gas port size and pressure and so on...guess work at the field level.