If you keep clicking the photograph will enlarge from thumbnail to full screen.

I think you are right in your assessment of the types of rifles used. The one next to your Grandfather is definitely the experimental Long Branch sniper rifle, and you Grandfather is holding the later Canadianicon version of the No. 4 with the pistol grip and Jostam recoil pad.

Good work in identification. It also proves that the Long Branch experimental sniper rifle was actually used and tested at the time.
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