As for ammo for the Benelli MP95E, I've always used CCI Std Velocity blue tag. I was cautioned when I bought the gun that I should only use that CCI round or Remington Std Vel ammo. I've tried several other rounds and all have failed. The gun likes a round that has a muzzle velocity of about 1050-1100 fps. Both the CCI and Rem rounds are in this range. All the others caused an extract hangup failure. The CCI is also an awesomely accurate ctg for this gun.
I tried a drop of oil on the top of a round when inserting the magazine and that helped a different problem that I was having.
For sites, I bought a cheap reflex site that works great. With this combo (ammo & site), I routinely shoot 30 rds at 10 meters into a 3" circle with most in the 10 ring and X ring offhand and unsupported. Great recreational shooter.