Am I missing something!

[Bruce_in_Oz]

The saga continues:

“Instructions for Armourers, 1931” (Brit issue, War Office 30th September 1931), Part II,SMALL ARMS, Chapter 1, RIFLES, Section1- Stripping and Re-assembling, Section 14 (iii), states:

(iii) Swivel screws – With the screw head supported conveniently, expand the hollow point of the screws, by means of the centre-punch, sufficiently to prevent them from working loose. The expansion must not be overdone, as this will cause damage to the slot when stripping.

“SLOT"?

So, a reference that implies that the screws, IF correctly staked, may be removed without “drilling out” to relieve the conical staking.

I cannot find anything (yet) that specifies that the “old” screw is to be “re-used”. Backing it out might be “easy”; getting it started again for reassembly might get interesting.