Rob McLennan is the gentleman, and they were to be used as a replacement for C3A1's that had been shot out. This was due to Parker Hale going out of business. I've never heard of any every reaching the requirements for replacement though. Even then, we were just instructed to set back the torque shoulder, breech end of barrel and recut the chamber to extend the usable life of the barrel.
No spare parts could be procured by the LCMM for the C3A1, ergo why we now use the C14 Timberwolf, which by the way actually require replacement barrels upon reaching 3000 rds - not bad for a rifle that cost DND $16,000 - yuck!
The C3A1 is now relegated to target rifle status and will very soon be withdrawn from the supply system. Navyshooter is probably the last guy to win the sniper comps at Connaught. I doubt it'll be around for next years comp. Wpns techs are now only being given famil training - no more formal hard training.
I worked on these things exclusively for almost 2 years -loved every minute. When I worked for base maint in Meaford, I assembled the Unertl's onto 10 of em, as they were in long term storage for the RCR sniper det. The Unertl's were still in their flimsy boxes as they came from Unertl himself.
Here's something neat - I know of an USMC M40A3 with a Canadian C3 Unertl on it - during the 1st Gulf war, the USMC grabbed all John Unertl had produced - including those earmarked for Canada. The trials scopes are sitting in CFB Borden - used as training aids in the school.
Kinda sad to see the C3A1's go away. They could have lived on with a magnum calibre if the Canadian army had been smart. 338 LM has it's limits - like burning out barrels

Alas no more parts could be procured so - byebye!
Somebody in the USA just sold the PH mount for a C3A1 within the last 6 months. It is now sitting in a collectors hands on New Zealand. It had been welded onto some cheap POS rifle action. From what I seen of it, it could be repaired by a competent machinist. He was going to put it onto an M87 rifle that he owns, along with his M82 and M85
I used to own one of the experimental transport cases for the C3A1's trials(I still regret selling it 10 years ago) - used in CFB Gagetown - still had the CF supply system sticker on it. As the Canadians didn't use them and went with the Pelican 1750 in green, they were returned to the manufacturer's rep here in Ontario. I only know of one that ever escaped destruction and I owned it for about 2 years(bought it at the Jane/7 gunshow for those that remember that great show). They were just AI cases that had had special internal foam cut out for the C3A1.
I could talk forever about what I know of the rifle - was a pleasure to work on it whenever I had a chance. Anybody needs any help with a build I can help you immensely, let me know as I still have copies of my CFTO's of the C3 and C3A1 -crafty little wpns tech that I was

making copies!