Personnel from 4th Battalion the Duke of Lancaster's Regiment have taken part in training in Otterburn after their international exercise was cancelled.
More than 100 reservists from 4 LANCS were scheduled to take part in Exercise Viking Star in Denmark until the coronavirus pandemic forced a change to their plans.
Instead, the reservists took part in live-fire tactical training in Northumberland as part of Exercise Resilient Lion 2.
It was held on a disused runway along the Scottish border last month.
They simulated different scenarios that the British Army may face in future operations, with the recruits training in both the day and night time.
Their training focused not only on taking out the enemy, but on how to do it, meaning they have launched different kinds of assaults under simulated enemy fire.
For many recruits, it is the first time they have ever fired a weapon at night and, as a result, the training is focused on testing their stamina and accuracy.
Lieutenant Colonel Nick Kennon, Commanding Officer of 4 LANCS, described the difficulty in reorganising after the Denmark cancellation.
"[In the] space of a couple of months we’ve had to take an exercise planned overseas hosted by the Danish military, find locations in the UK, identify what training potential that would give us, and then redesign our exercise so it fits within the availability of the ranges we have," he said.
"So yeah, that has been a challenge."
Coronavirus precautions also changed how the troops camped out on exercise with new individual amenities like their own washbowls, spaced out camp beds, and their own personal solar showers.
"What COVID meant was we had to literally stop all training for a time but certainly, with recruits coming in from their families, we had to be very careful indeed bringing them in," Lt Col Kennon said.
"So, unfortunately, we lost a bit of momentum.
"Now that we’re back to training and recruits are coming in again we’re loading them onto training courses but, of course, there is a backlog.
"There’s months of recruits who are interested and want to join and the challenge for us is to get them into the system as quickly as we possibly can."
The British Army resumed some training after the first national lockdown, with basic training gradually restarting earlier in the year at reduced capacity.
The aim of Exercise Resilient Lion 2 at Otterburn was to get the recruits operating on the same level as the regulars, in order to integrate them on the battlefield and allow them to deploy on operations.
"We operate in day and night, obviously we need to be prepared to fight the enemy with light and without," Second Lieutenant Matty Jackman, a platoon commander of C Company, said.
"It’s absolutely essential that we practice with the pieces of equipment… the night sights and the LLMs [laser light modules] so we’re absolutely ready to defeat any enemy that we’re facing."
Some of them will now go on to deploy to east Africa where they will be sharing many of the skills they have learned with the Kenyan Army.