You're hardly ever going to be able to bring heavy artillery to bare in a direct fire mode against bunkers in the Jungle when you're advancing through.
The best guns for jungle warfare would be the German 7.5cm & 10.5cm LG40 and the 10.5cm LG42. Weighing in at 146 kg (7.5cm LG40), 389 kg (10.5cm LG40 & 10.5cm LG42), and with a range of 8.6 km to 8.9 km, being a capable AT weapon and great artillery pieces for both direct & indirect fire they were ideal for the role.
7.5cm LG40 alongside Brandenburger elites:
10.5cm LG42 in action on Crete: