here at 13:52 and further you can see that RPG-7 grenade can't work vs fence etc
Well, it can work, its just depends if, in the case of the PG-7 projectile, its VP-7GCh nose piezoelectric-based sensor strikes a fence wire, or in the case of other statistical armours, a bar, slat, or central node. If it strikes one of those, then it goes boom and your are screwed!
If it doesn't strike one, then what happens next depends on the spacing between the wire/bar/slat/nodes, the diameter of the projectile and its fuzing system.
If smaller than the spacing, then the projectile will pass straight through, impacting whatever is behind it eventually. If the nose section (windshield, not the sensor on the tip) strikes a wire/bar/slat/node, then it may rip into the nose and if strong enough (bar/slat/node), rip into the body of the warhead.
If the fuzing system uses two-layer nose that forms the two conductive pathways of the electrical firing circuit, common on many many Russian RPG-7 and other RPG weapon projectiles (*), then it will short the firing circuit, dudding the projectile. This dud then slams into the base armour, if there is some, the impact disrupting the warhead and likely causing the explosive fill to deflagrate. If the armour is stronger, bar/slat/node, then it will likely disrupt and deflagrate the warhead at this point.
(*) Most of the rocket-boosted projectiles (**) of the rounds fired by the Russian RPG-7 family of launchers use this piezoelectric nose sensor and dual layer nose method of fuzing. Only the rear charge of the PG-7R does not, and its front charge uses a wide diameter nose sensor, so increasing the chance it will strike a wire/bar/slat/node. Almost all of the rockets fired by the other RPG-designated weapons (16, 18, 22, 26), also use this method. Only the RPG-27's PG-27 and the RPG-29's PG-29 differ, both using the same warhead system as the RPG-7's PG-7R, just different propulsion systems.
(**) The RPG-7 and RPG-16 are recoilless guns firing rocket-boosted projectiles. They are not a rocket launchers, this as the system they use to project the projectile from the bore is not a rocket, but the same as a recoilless gun (rifle). Only after the projectile has travelled a safe distance (time) from the operator does the rocket motor ignite, boosting the projectile's velocity. Some rounds, such as the OG-7V (OG-7 projectile), have no rocket motor at all, though it does stop people calling its expelling/propulsion charge a rocket motor.
