Proprietary solution of LCT regarding the blowback system in AK replicas differs from that used by other manufacturers. First of all, the way and faithfulness of recreating the dummy bolt assembly and the return spring. The method of connecting the dummy bolt assembly with the piston and the significant increase in the total mass of moving parts forced a significant redesign of the piston and increase in its strength. The complete EBB set is presented below. Pay attention to the extended bolt hook cooperating with the piston (unfortunately, the piston itself can not be seen in the photo).
The bolt hook at the back of the piston in the LCT solution looks like this:
Due to the high mechanical load, the piston is made of a single piece of steel. The teeth cooperating with the sector gear are not a separate insert but are an integral part of the piston.
Exactly those pistons are about to be released. Both those equipped with a hook dedicated for the EBB system and universal ones made in the same technology will be available. Both will be sold in a set with an aluminum head with a full bearing.
The EBB piston (manufacturer's code PK365):
And the universal piston (PK367):
Due to the narrowed teeth, the pistons are dedicated to cooperate with super torque-up gears (32:1 ratio), but of course they will work with every other. And here is the note: it does NOT work the other way around. 32:1 gears require narrowed teeth on the piston, do not work with full width teeth.
Will steel pistons allow for achieving supernatural muzzle velocities? In my opinion, no. The problem will most likely be the mass of the piston. The ones described above , together with the head, weigh respectively: 69.2 g with EBB hook and 68.0 g, without one. For comparison, a standard LCT polycarbonate piston with half-teeth and an identical aluminum head weighs only 29.6 g, and an SHS openwork aluminum piston with a head, 30 g. The difference is more than double the weight. Thus, the energy transferred by the piston to the gearbox will also increase significantly. As how will it affect the longevity of the frame itself, it is not difficult to guess. Probably that's why LCT uses these pistons in conjunction with 32:1 ration "slow" gears, a slightly lower rate of fire will probably prolong the trouble-free operation of the system.
On the LCT's website, steel pistons bear the annotation "coming soon". The price is not yet known.
