Jingji's PDX has been on the market for quite some time, but I've never had the chance to do an unboxing and review. Today, I'm finally unboxing a Jingji PDX. The material and craftsmanship of the PDX are comparable to that of the SR16, featuring familiar material and paint finish, essentially a thicker version of the SR16. The paint on this gel blaster will peel off quickly, but there's no need to worry. The paint on the zinc alloy small parts is the same as the SR16, proving slightly more durable than the Sijun. The assembly is quite impressive, and the quality of Jingji's molds is quite good, with the only drawback being the paint finish.
Detailed Mechanism of JJ PDX
The handguard is at a 416 gel blaster height, theoretically universal. However, when attempting to install a Nantong 416 handguard, the rail stop block slot is slightly small, requiring some grinding. The QD mount on the handguard is a slanted hole, which doesn't hold the QD buckle securely.
The stock is from the SLR inventory with new engravings. Some say the real firearm also has this stock. I think installing an old land stock on this kind of modular design can also be seen as a restoration of the real firearm.
The nylon three-way seat and the knurled barrel are also from the old SLR inventory. The tennis racket lacks a pin for secure attachment, instead using an internal hexagonal screw. The grip is new and feels good, but opening the bottom cover is a bit of a hassle. There's a partition near the bow guard, the purpose of which is unclear. What do you think?
The spring pin of the front pin is quite tight and can't be knocked out directly. It needs to be pressed down at the small hole of the pin hole to knock out the pin.
When disassembling this kind of gearbox with a double-speed mechanism, make sure to remove the speed mechanisms on both sides before the gearbox can be removed.
The grip only has two screws. I personally suggest adding two more, otherwise, it might feel a bit loose.
As for the gearbox, it seems to have changed in size. I don't have a GSL and SLR gearbox on hand, so I can only make a rough judgment based on my memory. If you have these gel blaster models, you can let me know if my memory serves me right.
The recoil plate and charging handle are the same as the GSL. There's still no pre-supply. The speed mechanism gear that links to the SR16 is the same, the right side speed mechanism will always have about a 20-degree return difference. The modulus is slightly large, which may be related to the casting process.
The grip seat has abandoned the SLR's split design and made it one piece. I still quite like the design of the split seat, as it's easier to adjust the teeth. The material of the gearbox shell is much better than the SLR and Sijun, offering greater potential for upgrades.
The cylinder is 85% air volume with a limit groove. The inner barrel is 17.5cm long, the air volume is slightly large, a 50% recoil cylinder is more suitable. I cut the limit and changed to a 60% cylinder, glued the cylinder head with 704, acting as a stop.
The nylon head of the ladder is okay, AOE. The cake tooth is cut with one tooth, the tail top is the same style as the SLR, but it's made of zinc alloy. The bearing is MF83 without a retainer, the gearbox shell lacks oil, remember to add a circle of oil to the seam of the inner and outer rings of the bearing, turning a few more rounds will always lubricate the ball.
This one arrived firing semi-auto in full-auto, the small ear of the switch group moving contact was slightly worn, but mainly it should be an assembly issue, reassembling the semi-auto brought it back. The nozzle is the same as the GSL, the inherited large opening without an O-ring, discard it upon arrival.
The nozzle lock force is insufficient, on one hand, the bolt carrier spring is not strong enough, on the other hand, the nozzle is not long enough, it can't reach the inner barrel. The size of the nozzle is the same as the SLR, I highly suspect that the size of the gearbox shell has been modified, the position of the cylinder head is offset to the back, or the head of the gearbox has been extended. I got a double O-ring nozzle, removed the rubber, padded a 0.5mm diameter O-ring, extended the length of the nozzle, it's suitable.
The SLR has the same large spring, 170 long, normally should run 80, but the factory only has 65-. Did air tightness and changed the cylinder before running 66-68, changed to a 60% cylinder runs 70-72. I feel it's still a bit low, changing to a 50% cylinder or extending the inner barrel to 25cm might be better. The factory motor, the torque feels slightly improved compared to the SLR, the SLR runs 16 rounds per second, the PDX runs 18.
It's said that the gearbox will be sold separately, but it's been half a year and there's no follow-up. But referring to the pricing of the SR16 and GSL, I guess there is no cost performance to speak of. There's no longer the extreme cost performance of the self-assembled SLR gearbox for 118 and the gearbox shell for 28, times have changed.
