The Brits lost huge numbers of Lee-Enfields and 303 British ammo at Dunkirk. Many more of these guns - and related ammo - fell into German hands in other settings.
The Germans were famous for pressing captured weapons and equipment into their own use use - even printing German-language SVT-40 manuals and manufacturing 7.62X54R ammo to equip their own troops with SVT-40s. Why didn't the Germans use captured Lee-Enfields? What happened to all those captured Lee-Enfields from Dunkirk and otherwise?
Why would you use a weapon that allowed your enemy to lose their battle against you ??
That’s like watering down your genetics with the blood of those whom you've conquered !!