No4 Question

[Seaspriter]

I thought the hollowed out bolt was unique

The hollowed out bolt was designed for the No.5 "Jungle Carbine" but was used in production (along with the solid bolt) in the UK on a somewhat random selection basis -- whatever was in the assembly parts bin. I have a couple of No.4s with hollow bolts. These tend to show up mostly between 1945-49 on new production and FTR (Factory Thorough Repair) guns.