OTTAWA, Ont. -- After decades of service, the military's last Lee-Enfield rifles are finally getting close to retirement.

Colt Canada of Kitchener, Ont., has been picked to design modern rifles to replace the vintage firearms used by the Canadian Rangers.

The military will get a chance to test out 125 of the new weapons next summer during its annual Operation Nanook training exercise.

After testing and tweaks, Colt Canada will then make more than 6,500 rifles, along with spare parts and accessories, which the Canadian Rangers will gradually start to use between the middle of next year and the end of 2019.

Finding spare parts for the Lee-Enfields is a challenge because there are so few manufacturers left who make spare parts for the rifles, first introduced to the British Army in 1895.

The current crop of rifles, which were purchased in 1947, come in their original boxes -- but supplies are dwindling.

Prime Minister Stephen Harper was told last year that while the weapons are in mint condition, supplies are limited.

"While Rangers are given rifles in pristine condition (i.e. new from the box from special storage), Canada's stock is diminishing and a replacement needs to be identified within the next four to five years," says the memo, which was sent to Harper last October.

The replacement weapons probably won't be that much different from the 67-year-old Lee-Enfields, says the memo, obtained by The Canadian Press under the Access to Information Act.

"It is important to note that despite the date of manufacture, rifle technology has not changed significantly over the past 60 years and the replacement rifle will likely be very similar to the Lee-Enfield."

The bolt-action rifles are standard-issue weapons for the roughly 5,000 reservists scattered across 200 communities who comprise the Rangers. The weapons work well in the North because they don't tend to freeze up or jam.

Harper and Defence Minister Rob Nicholson got a chance to see the Lee-Enfields in action last week as part of a series of military manoeuvres on the southern tip of Baffin Island.

"The rifles that they have are capable," Nicholson said Aug. 26.

"They work. They work in this type of climate, but we're on track to replace them, and it's my hope that next year they will be replaced."

In 2011, Public Works put out a call to companies for specifications for 10,000 replacement rifles, but defence industry sources have said that the program has been held up over concern about who holds the design rights on certain weapons.