Sometimes it’s good to see what the trainwreck is going to look like before the train comes off the rails and wrecks. Some might call this troubleshooting, but the British government would call this the final L-85 and the L-86 prototypes, the XL-85 and XL-86, respectively.
Compared to the XL-70, the weapons exhibit few larger changes and mostly boil down to General Dimensioning and Tolerances (GD&T for those in engineering fields). Recognizing that a main enemy of weapons function is the ingress of debris, the Enfield engineers set about tolerancing the interface between the bolt carrier and the body of the weapon.
**Side note – for a great example of why keeping stuff out of a weapon is a big deal versus being able to function somewhat with it in, check out InRange TV’s mud tests of the M16 and AK-47, respectively.
The other main change was to the magazine body. Instead of the poor choice of a separately tacked on the magazine well, the designers opted for a completed magazine well that was welded into the body as a complete unit – much better for holding tolerances.
But, they could not solve a major issue of weapons having “split groups” or differences in POI when the weapon is in semi-auto versus fully automatic fire. The L85 would split groups, sometimes even significantly, when used on full-auto – which was a major problem for the Light Support Weapon version.
For the full details, check out Forgotten Weapon’s video on the L85, part 4 below: