I searched the Bisley archives and found out that CSM H Rusk competed there 5 times. 1929, 1930, 1932, 1936, 1939. Canada scored highest in 1929 and 1932; Rusk shot his best at 144 in 1936... that was in July '36, so indeed he was on his way on commercial Cunard voyage that left Monteal on June 12th (on the SS Alaunia pictured below) There is a Canadian Pacific label over that 1936 Cunard label, he probably took that Canadian Pacific ship when he went back in '39 - I cannot read the label though.
MATCH FIFTY-FIVE - 1929
Fired on Tuesday 16 July 1929
CANADA
Commandant: Lt Col GT Chisholm VD
Captain: Capt WG Colquhoun MC
Coaches: Lt Col RM Blair, Capt A Martin
Reserves: Lt D Fyvie
CSM AC Lucas 46 48 44 138
Sgt JH Regan 46 46 45 137
CSM H Rusk 47 45 44 136
CSM GM Emslie 46 44 45 135
Sgt JWA Sharpe 44 46 45 135
MGnr H Collings 46 48 41 135
Capt JT Steele 42 47 45 134
Lt DT Burke 43 45 45 133
---- ---- ---- ------
360 369 354 1083
MATCH FIFTY-SIX - 1930
CANADA
Captain: Lt Col RM Blair
Adjutant: Lt SW Graham
Coaches: Capt A Martin
Reserves:
Lt J Bowen 47 49 47 143
Lt DT Burke 49 47 46 142
Lt AC Carter 48 48 46 142
CSM GM Emslie 49 46 46 141
Sgt CW Foam 44 46 48 138
CSM H Rusk 45 48 45 138
Sgt JH Regan 45 46 45 136
CSM WA Hawkins 44 45 46 135
---- ---- ---- ------
371 375 369 1115
MATCH FIFTY-EIGHT - 1932
Fired on Tuesday 12 July 1932
CANADA
Captain: Lt Col AG Styles DSO
Adjutant: Maj F Gardiner
Coaches: Maj F Richardson, FV Shepherd, Lt JN Dow
Reserves: None
Lt DT Burke 50 49 47 146
Lt AR Sweet 46 49 49 144
Lt GE Matchett 49 49 44 142
CSM H Rusk 45 46 48 139
QMSgt H Burton 48 45 46 139
Capt J Houlden 46 46 46 138
QMSgt A Parnell 46 47 45 138
CSM GM Emslie 46 48 43 137
---- ---- ---- ------
376 379 368 1123
MATCH SIXTY-TWO - 1936
CANADA
Captain: Lt Col ND Dingle
Adjutant: Maj KM Holloway
Coaches:
Reserves;
CSM R Rusk 48 48 48 144
Sgt JR Kier 45 48 49 142
Lt H Parker 46 49 47 142
SQMS FV Shepherd 48 47 43 138
Lt PJ Martinson 43 48 44 135
Sgt JWA Sharpe 44 46 45 135
Sgt Maj R Kiddie 42 48 44 134
Capt SW Graham 47 46 40 133
---- ---- ---- ------
363 380 360 1103
MATCH SIXTY-FIVE - 1939
CANADA
Captain: Col CB Price DSO DCM VD ADC
Adjutant: None
Maj RS Harrison 50 44 49 143
Capt AC Lucas 50 47 45 142
CSM H Rusk 47 48 45 140
Lt S Johnson 45 46 45 136
Cpl T Gregory RCAF 45 47 44 136
Lt CF Kennedy 46 46 43 135
Cpl HD Whitehead 44 49 42 135
Sgt A Parnell 42 48 44 134
---- ---- ---- ------
369 375 357 1101