A little trick I use when setting the timing on anything with points, is, instead of bulbs or buzzers etc. what I use is an old transistor radio, off channel, and place it near the points, at the point of opening, the radio 'cracks', I find it very accurate.
You can use a compass too. The needle swings as the coil starts to break down.
That said, my previous comments about backlash and trial and error still apply. There are 5 gears between the crank and the points so there is a whole lot of error in the system. An approach of getting it "close enough" then tweaking it is probably best.
The old way was to trap a fag paper in the points. The timing point is when you can pull it out without tearing it. This is almost certainly in the right ballpark to be going on with.
I've seen a video of Indian street mechanics leaving the backing plate slightly loose and adjusting the timing with the engine running by tapping the plate round with a screwdriver handle then locking it down when they get maximum revs.
The best way is to take off the chain case and rotate the engine (always forward) with a spanner on the alternator.
Set the piston distance before TDC to 9mm and check that the ammeter does NOT twitch when you push the points to the fully advanced position.
Then rotate the engine a tad until the piston is at 8mm before TDC and check that the ammeter does twitch when you push the points forward to fully advanced.
Adjust the points until the above works and the fully advanced timing will be set to the recommended 32 degrees to within 1 degree.
And finally got some more time working on the Enfield last night, and as the light faded the score was a resounding 1 - Nil to the good old Enfield, how difficult can it be I hear you say the guy is only removing a timing cover, oh no this is no ordinary timing cover this timing cover was sent up from the horned guy himself, so just to refresh remove all 10 bolts and ease off the cover, no remove 9 and the one that sits just above the rear oil pump won't move, screw driver no, impact driver no, heat no and finally one side of the head snaps off, so last night cover up the side of the engine and tape up well and take off the remainder of the head with the die grinder, that should do it gentle tap with the mallet and slide it off the bolt oh it wont budge, ok time to get brutal with it drill out the bolt, lots of penetrating fluid and still no good, so drill out a bit more and more fluid and mallet handle behind front of the oil filter housing and large screw behind the rear and gentle rocking motion right it's free from the gasket, but an hour later it still hasn't budged off the dam bolt, at that point all tools were downed and with tail between my legs I sulked off to bed, so has anyone else ever had to fight the evil dark lord that pretends to be a timing cover.