The experts from CFSL, which is under CBI, went to the Chattarpur farmhouse this morning along with police officials where they reconstructed the scene, a senior police official said.
Initially, they had taken Sachin Tyagi, the PSO of Namdhari who allegedly opened fire at Ponty's brother Hardeep, to the spot and later Namdhari.
The CFSL team basically tried to ascertain the tragectory of the bullets fired, based on the statements provided by Namdhari and Tyagi, the official said.
However, the statements and the reconstruction of events made it clear that there were discrepancies, he added.
Delhi Police had alleged Namdhari had opened fire at Ponty's brother Hardeep during the shootout at Chattarpur on November 17 in which both the brothers were killed. Namdhari had said he did not fire at Hardeep.
Investigators also suspect Namdhari tampered with his gun.
Namdhari's son, a relative and driver, who allegedly helped him in tampering with the gun, were absconding, police said.
Investigators said only a thorough investigation would make it clear whether Namdhari used only the pistol or any other firearm at the farmhouse.