shardbearer

Larger plunger tubes aren't always better, not only for the reasons above, but because for a given spring load, you can't create as much pressure in the plunger tube and barrel. For example, if you have 10kg of force from the spring, then a 1.5" ID plunger tube could produce a maximum pressure of 0.86 bar, while a 1" ID plunger tube can create 1.94 bar. I'm working on a program to simulate springer performance, the numbers it's getting right now are a bit higher than real world numbers, but it's saying that the optimal plunger tube inside diameter is about 30mm.

After beefing up the retention mechanism, it becomes impossible to extend the stock again after you collapse it. The solution is pretty simple though, just cut out the notches that lock it into the retracted position.

Wiring LEDs in parallel is the standard way of doing it. With higher voltage batteries it's better to wire several LEDs in series with one resistor to make a string, and then several strings in parallel. Each string needs its own resistor though.

If you already are putting a lipo in your blaster, it's totally fine to run them off of that battery. You don't need a voltage regulator. Note that the LEDs will dim when the battery is under heavy load.

I had the same problems finding them in stores, and bought it on HasbroToyShop. Their cheapest shipping option was not that cheap so you might want to buy multiple items at once, but it ended up being 2 day Fedex Ground instead of the 7-10 business days they quoted.

It's decent. It's convex so it tends to slip on your shoulder a bit, and I've been thinking of gluing some grippy foam or rubber to the back. Length is pretty good, I locked it to the longest setting by putting hot glue behind the ratchet nub. It still collapses under a lot of force, but this isn't a springer so that isn't an issue. It's a pain to get open because the hinge pin is permanently attached to the orange piece on both sides, which means you can't permanently glue the tube to the body and still be able to reassemble the stock. I took some pictures so I can write a guide for opening it up and putting battery wires through.

I also have a grip extension from 3D Printed Solid on this blaster which I forgot to put on for the photo, and I really like it.

Edit: Stock mod guide is here.