Distance: 3.3 km (3.0 DOC hours) - Unmarked route, hard - Moderate-hard terrain
Altitude: 1358m to 1799m. Gain: 354m. Loss: 786m . Gradient: 21 deg (Moderate-hard)
Skills: Alpine weather (2/7)

Unmarked route, hard (8/9)
Unmarked route, no clear geographic features to follow

Primary, mapped (1/5)
Formal route, on maps, principal access to hut or along range / catchment

Moderate-hard (difficulty: 4/5)
Continuous moderate climbs

Moderate-hard (difficulty: 4/5)
Tall, walkable scrub / large rocks, occasional waterfalls or gorges in rivers

Alpine weather (difficulty: 2/7)
Tramp on open tops, exposed to alpine weather

Unknown (difficulty: 0/6)
Not specified

Unknown (difficulty: 0/7)
Not specified

No description

Note: Described in the reverse direction to your journey

From the bushline on Travers Saddle - Sabine track, sidle on tussock and eventually rock debris ascending diagonally to a tussock or light scrub rib. Continue up this rib then diagonally north to a shoulder at about 1780m. This is to avoid the very steep country between 1400m and 1700m below the shoulder.
From the shoulder descend into a rocky basin (it may be easier to go further east than the route line on map shows) and sidle north, with a bit of up and down, to the bottom of the gully which leads to Gunsight Pass. Climb the broad and not-too-steep gully to the pass.
Most of this route is visible in the photo in book "The Fold of the Land - New Zealand's National Parks from the Air" by Lloyd Homer & Les Molloy, from which I got the idea to do the route.