Thursday, March 26, 2015


We have all heard of the Nerf Mega Bigshock by now, and spring upgrades and .50 cal conversions have already been thrown around. I figured I would snag one to mess with.

[insert stock photo of a factory Bigshock here]

Out of the box, it was obviously underwhelming. I took 4 chrono shots which hovered around 58 fps.

This is the piston group disassembled:

The rod is some kind of soft plastic, probably PP, like a Triad rod also seems to be. The end plate has speed holes from the factory.

The piston head has a thick molded rubber pad from the factory (Please do not argue about whether to remove the AR!) and is attached with one of these press fit pins instead of a screw. Hasbro seems to skimp on this lately and I am not sure why, a hard enough yank and you will rip that fastener right out. With spring upgrades, getting rid of it is mandatory.

I ran an 8-32 tap into the rod and installed a screw with plenty of thread engagement.

It is interesting to note that the piston on these is not keyed to the rod. It can be rotated freely. This may be useful if the step on the piston where the sear engages gets worn, to extend the life of parts.

Watch out with the rubber bumper. It should stay on fairly well, but if you don't have a large washer or screw head, it could get dislodged. You may want to CA it to the piston.

The rear barrel plug is solvent welded to the frame and is designed as a cosmetic part with the stock shell. I, however, have discarded the shell, so this will not be retained, a simple plug will be fabricated. AR is a standard D'Andrade valve, just bigger, and has a rubber insert.

There is a step in the barrel, not just the peg supports, which prevents inserting dart foam past the end of the tight section of the bore. I ground this away carefully, since I want to load darts flush like I do with my .50 caliber Jolts.

Spring is nearly identical in dimensions to a Buzzbee Tek spring.

I tried out this Tek spring plus a stock Swarmfire spring and bagged 78 fps. I then settled on a shortened Everbilt which produced about 91 fps and is very nice and snappy. Proper data on the final build will follow when I have enough ammo to do a shoot.

This hole was found in the piston head. Be careful, it goes through to the backside and is how the usual AR vent port is implemented. Fill it with Devcon or the like.

Speaking of vents, this is a type of ported cylinder. The two bulges on the outside of the grip are where two slots, like transfer ports of a two-stroke engine, are, which prevent any compression until the last approx. 1.25" of stroke. Yes, some may complain about "those dreaded holes in the PT" and "nerfed performance potential", but for the stock barrel, there is probably nothing wrong with this and little to gain, in fact there may be something to lose by changing this feature.

However, if you will put a longer barrel on one of these, it can be trouble. Cartaya has already discussed de-porting the Bigshock the hard way.

The stock O-ring seals perfectly. If the barrel is plugged before firing, this one will hold pressure for well over 15 seconds without leaking at all, and has minimum friction. Don't tamper.

And here is the result. I cut off a bunch of webs, ribs, tabs and other now-unnecessary shell provisions on the outside of the frame and end plate and reshaped the front of the trigger guard, which do help quite a bit with comfort. The top tab on the muzzle was kept as a front sight post. The plug in the back of the frame is a piece of sheet bonded to 3/8" of 1/2" PVC which was filled with epoxy putty for dead volume removal.

Shoots real nice. It has some serious snap to it, feels exactly like a scaled-up version of my .50 cal Jolt should, and oddly enough these darts seem to get more accurate the faster I shoot them.

Obviously, with a .50 caliber insert you could get some serious velocity on a micro. I am not doing that, since a major part of the appeal of these things is the 20mm hand cannon factor and the utility of shooting darts often assigned anti-armor and enhanced damage effects. Also, about those rear frame plugs, there is no reason to make them fixed. I made mine fixed because again, I am just going to muzzleload a mega. I have seen concepts for RSCB feed tubes placed there. A convenient fitting for modularity is a 1/2x3/4 CPVC CTS bushing. Hint hint.

Friday, March 20, 2015

The Next 2s Solution?

When looking for some e-sky and blade motor listings, I came across these:

Their specs are quite superior in terms of 2s lipos, drawing 0.75A continuos each while blades would draw ~0.6. The RPM on these would be hitting the 40k mark while blades would hit ~28k. For 3s, I still think blades would be better but these seem to be better on 2s. In terms of price, these are about $3 a piece which seems to be a bit cheaper!

Since these are 180's, their inertia and torque should be substantially higher than that of 130's. These are in fact, carbon brush so there is no need for getting all worried about stuff like: "Am I going to burn out these motors?". For those of you who aren't familier with what carbon brushes are, here's a photo:

Photo credit goes to SSGT on britnerf.

So basically, the things on the left are parts of a standard metal brush motor. the brushes which are the things at the top are very thin. The problem with that is that you will be sparking these brushes all the time whenever you put power into the motor. That brush will get worn down as heck! Now look at the things on the right. Those are the parts of a carbon brush motor. Look at its brush set at the top. It has two chunks of weird things right? Well those weird things are what makes carbon brushes carbon brushes. They are chunks of carbon that help with brush wear.

Thursday, March 19, 2015

The case for calling them magazines

I do not mean to nitpick, but improvement could be seen,
If we could bring ourselves to say exactly what we mean.
- Jeff Cooper
Is this a clip or a magazine?

Magazine describes the form and function of this device, and clip is the name that the manufacturer has chosen to give it. Either term could be used and would usually be understood - but which term should be used?

This is a debate which pops up every once in a while on r/Nerf, and this is a contentious and surprisingly divisive issue. Every time this debate has occurred, my opinion has shifted a little. Specifically, it's shifted from
"Who cares?" to "Magazine. It's a magazine, dangit!".

Here's why. 

Sunday, March 15, 2015

WIP- Eradicator Rapidstrike with Rayven Stock

Time to start building a primary!

I love the ergonomics on the rayven. The thumbguard, the shoulder stock, I absolutely LOVE IT. But, it doesn't have those full auto capabilities of a rapidstrike which are very superior. So, this happened.

Right now it just has a temporary bond of hot glue and melted plastic to see if the integration will work.

 Massive microswitch for the rev switch

And... it's fitted.

What's a flywheel primary without 180's?

180 on the pusher because, why not?

Yep. You're seeing that correctly. Teflon tape to cover the connections because it conforms to the shape very nicely and it looks really clean.

Hmmm, handy bit of shell here. what am I to do with it?

This. Cover the motors. If I do say so myself, it looks quite nice like that.

Thursday, March 12, 2015

Shelf watch: Crossbolts, cheap Demolishers, lots of variety

There haven't been any shelf watch posts from me recently as stock has been moving very slowly over the last few months at the local Walmart - but, as of my visit earlier this week, there are several new things worth noting.

This will be an imageless post because, while I did have a camera, none of the pictures turned out well.

Tuesday, March 10, 2015

Hammer "Completion" (?)

Reactions to my new pump gun on Reddit:

Don't worry guys, I haven't been converted to the dark side, auto is still better, wait till my next build. Now all this click-click-booming has left my Tacmod a bit lonely, time to shoot off a few mags...

Sunday, March 8, 2015

Practical stock class: Dual wielding

I know what you are probably thinking: "Really? Practical stock class: dual wielding? Shouldn't that be impractical stock class?"

Dual wielding has a lot of detractors, and, to be fair, this is not for no good reason. Having a blaster in each hand has a few very obvious advantages and a host of slightly less obvious disadvantages. It is therefore the domain of those who take their inspiration from action movies and haven't thought their system through in much depth.

It is not, however, the exclusive domain of such people. Dual-wielding in Nerf is a viable system, with advantages and disadvantages, and which can be made to work if done right.

This post has been written with HvZ in mind, both because the entirety of my experience with dual wielding comes from HvZ, and because dual wielding is less practical in other gametypes.

Saturday, March 7, 2015

WIP - Hammer - Pump Retal Build

I think it's about time I added a superstock pump gun to the armory. Just because.

The first thing many will ask, is Rampage or EAT. I wanted to steer well clear of both. The former is a sweet gun with a solid history going back to 2008, but sideloaders are not great. The latter is in short supply, I can't afford one now, and when I don't want a pump gun with $60+ worth of desire, I wouldn't keep one if I did own it - plus the thing is the most flimsy feeling and inefficient of the Elite CS guns as well as the most lacking of durability in hard use.

What I did have was a Retaliator, a solid and consistently sweet-shooting piece, which was begging to have a pump grip.

What was certain early on was that I was not going to just put an inner barrel on there and go. With something that isn't an auto, I can't afford any negative impact on koosh accuracy, nor do I want to lose any of the circa 105FPS that this thing has - so it was going to be a BFU barrel. I did not want to buy kits, use stock Retal handguards underneath the pump grip, use an accessory rail as a grip guide, have those janky angled links putting extra forces on things. Nor did I want a slide, since a flat top setup was mandatory.

I started with the barrel. I chose 3/4" SDR21 PVC pipe and was planning to build a bulkhead to mount it solid, but then I tried ramming a piece into the stock twist-lock muzzle. It only took grinding a flat on there to clear an internal protrusion and some Devcon and I had a perfect barrel install on the stock chamber.

Next the grip guide. I considered a coaxial pump grip but settled on a second tube below the barrel for the grip to run on. This is 3/4" Schedule 40 and is bonded to the barrel. The trunnion is one piece because none of the barrel stuff is clamshell and is Devconned on the right receiver half and screwed to the left through some PVC blocks with an 8-32 socket flat head.

The base of the pump grip is 1" Schedule 40 PVC sectioned and slightly expanded hot. The resulting grip runs smoothly on the rail with not too much clearance.

This is an 8-32 tee nut. Normally these are hammered into wood and used to accept a threaded fastener. However...

...This is a trimmed tee nut which will be used as a threaded insert in this build.

And here is one being torched. Why?

Because this.

I carefully set the inserts flush while hot, Devconned them in, and trimmed the outboard end. Now I have steel 8-32 threads in the bolt carrier, rather than pin holes that were too large already for me to tap or mess with for attachment means confidently.

Currently these and the 8-32 grip studs are the wonkiest thing about this gun and testing is pending. For now it is all working great, but revisions may happen to hardware in this area.

This is the pump grip after adding 2 more thermoformed layers and marking out for attachment flats.
And here is where a lot of pulverized PVC used to be. Freehand, grinder.

And even more pulverized PVC came from carving grip grooves.

This grip is a solid, heavy part.

Mocked up

Linkage fabricated. I was going to use aluminum, went for PVC sheet instead. Does the job, solid. The grip end is Devconned and the screw is there for insurance, which is why there aren't 2 screws.

Current state. Missing the (important) top accessory rail and the barrel shroud, the flash hider is still a blank, and there are some holes to patch in the receiver. So far, it doesn't look the greatest with those issues remaining, but it already feels great, points nicely, shoots just as this Retal always did, and is the most effortless and nice pump-action I have ever used.