I think a size 42 should already fit. At least if the Corsair is a Dominator without chest pockets. Here are the measurements of the Dominator.
SIZE | 42 Regular | 42 Tight Fit | 44 Regular | 44 Tight fit
CHEST | 116cm | 115cm | 121cm | 120cm
HEM | 109cm | 114cm | 113cm | 119cm
LENGTH | 63.5cm | 63.5cm | 63.5cm | 64cm
SHOULDER | 48.5cm | 47cm | 50.5cm | 48cm
SLEEVE LENGTH | 65.5cm | 65.5cm | 66cm | 66cm
SIZE | 42 Regular | 42 Tight Fit | 44 Regular | 44 Tight fit
CHEST | 116cm | 115cm | 121cm | 120cm
HEM | 109cm | 114cm | 113cm | 119cm
LENGTH | 63.5cm | 63.5cm | 63.5cm | 64cm
SHOULDER | 48.5cm | 47cm | 50.5cm | 48cm
SLEEVE LENGTH | 65.5cm | 65.5cm | 66cm | 66cm