what are these ?

What are these ?Attachment 106680Attachment 106681

Harrington Richardson produced mags for the FN when it was going through trials...

Your are correct, they are for the T48 rifle as HRA manufactured 500 examples, most were destroyed. I could never find a High Standard T48 magazine.

I had one of these rifles come into the SA collection I built in camp Gagetown NB back in about '95/'96... It had a cracked forestock which I spirited home one night to fix with Brownell's microbed and return. It had no breechblock because of our storage habits and had been shipped without, a standard FN C1 breechblock fit and functioned perfectly. I forget the serial number. I think it came in from one of our regimental museums as surplus, meaning they had two, or failed to know the difference between this and another pattern of FN.