Interesting approach shmmee. Unfortunately, it can be hard to know when this is applicable. I'll offer a more significant problem with using light darts than what has been mentioned. Optimal barrel length is a function of dart mass to a certain extent based on my experience and my computer simulations. I've noted before that when the darts are heavy enough the ideal barrel length is independent of dart mass (as long as this criteria is met, at least). But when the darts are extremely light, it's likely that the pressure in the barrel is going to be different than the pressure in the gas chamber or spring chamber, and this means that your optimal barrel length will likely be significantly different from what it would be if you used "heavy" darts. Is is that bad? I guess it depends, and testing would be the easiest way to see if it is bad.

All the rambling about friction also applies, but based on my simulations, it's not as significant as people think it is. And it's certainly not as significant as the effects from using a low mass dart.

To me, the easiest thing is to have a few barrels of different lengths and a chronometer. I don't really know what anyone's trying to avoid here as barely anyone has even bothered to use a chronometer. It seems to be common knowledge that this sort of testing is bad, but it's not that bad. People seem to spend a lot more time trying to figure out how to avoid using a chrono than it would take to use a chrono. I've done tests like this and it's not that hard or even that annoying. I spent perhaps an hour or two to measure 75ish shots.

I completely agree that a chronometer would serve as the ideal method, I've priced them before and have decided they are beyond my nerfing budget (though I do have a bone stock cross bow I'd be willing to trade for a decent chrono - if any one is interested Yeah, scratch that offer. 3 hours sleep can make you say stupid things). I was just trying to come up with a simple - low budget method for the many who are in the same boat as me.

I might look into the theory some day later, but I'm worried that it might end up being as much of a boondoggle as the rifled barrel discussion (which I foolishly let myself get sucked into). Had I the time of an uncommitted teenager, I would be more than happy to examine this concept at length, but screw that. I've got kids. I feel lucky to have an undisturbed 3 hours to mod, and defending this concept lays so far at the bottom of my list of nerfing priorities, it's picking pre-chewed gum off of it's face. Thanks for the input everyone,

Doom - as usual - you rock.

It'll work, but you might have to be a little picky about the darts you feed it. My RSCB'd panther feeds just about any cone tipped darts (elites, some third party darts) beautifully but it wont feed suction cup tipped darts or straight sided darts like the now popular waffle tipped darts at all.

My panther has a CPVC barrel adapted to a 1/2" pvc TEE on it - i did have to ream it to a smooth taper on the cpvc and pvc though.  

Imbedded video is great, but if it constitutes the only information your post contains, it excludes those behind a YouTube filtering work firewall, and smart phone surfers with limited reception/ data plans. The more comprehensive posts suggested above may take a little more work, but it can be appreciated by a wider audience.

I'm looking forward to seeing some internals from these compared to some of the other elites. I was jumping up and down over the retialator and rampage, but I'm feeling a little more chill till the actually release something new.

The Mrs. and I took the kids on a 5 hr drive to get a better view of the eclipse last weekend. Sadly, we confirmed that 5 hours in a car was pushing it for the toddlers and that 16 hours would be too much of a distance for a family vacation. Sorry to flip flop, but as much as we would love to vacation up there, I just don't think its going to pan out this time.

Very innovative, and a great use of parts- like many in the nic, I have plenty of extra hornet guts lying around just waiting to be used for something clever like this. Good luck getting the back pressure valve to seat against the larger opening have you considered the use of an o-ring or a small diameter neoprene washer on the end of the pen cap? Also, I noticed you used regular pvc cement on the tank and tee- Ace hardware sells a cement for mating pvc to abs and other plastics, it's in the can with the yellow label. Thanks for the inspiration!

I've tried a large rubber washer seated around the pen cap, but it wasn't thick enough to rise above the pen cap so the piston wasn't contacting the washer. I'll try raising it by placing an O ring above it on the nested Bic pen tube. thanks for the suggestions.

11/9/2010 Part II update:

Part II still isn't working. I realized the replacement Bic pen cap peg is 3.5 degrees off of, so tolerances are really tight. for my second try, Instead of replacing the center peg with a bigger center peg, i've tried resting a rubber washer level with the barrel peg, and filling the space below it with epoxy. It's now opened to .25" and holds pressure (good progress), but vents back out through the piston peg instead of shifting the peg out of the way and venting to the barrel. I'm thinking it's doing that because the piston head now sits flush on the rubber washer, so there isn't any piston head hanging over a peg for the air in the tank to get under and push against (moving the piston out of the way). Basically more surface area at piston inlet than at the piston outlet to push against.

Untill i get this last piece of the puzzle figured out you may want to hold of on this second part of the mod. (but part I still works great, and is really easy.) If i get it working i'll post the part II as a separate mod.

Nicely done, I always thought a hornet tank expansion might be viable, the only issue is its small opening. Have you tested this with a barrel yet? and if so, does the relatively slow air release effect range? (or is that one of the reasons for the outlet expansion in part 2?)

I haven't performed a comparative test to an un-modded tank, but when fired with a generous 16" cpvc barrel (not sure how much air pressure used at fire) The dart still fired with quite a bit of force.

I found more depends on how much tubing is connected to the tank, blast button, and pump. The less tubing used, (like in your "tiny tim" eliminator mod (very cool)) the quicker the system can vent and the quicker the piston can get out of the way. Which leads to a more explosive force applied.

Thanks for pointing me to your magstrike mod. I had actually thought about using the piston to load darts, but the output power was so low i gave up on it after testing it singled. That's an elegant solution to both problems.

edit. goofed reply

Easy Hornet Tank Capacity Expansion

And thus begins my first intellectual contribution to Nerfhaven...

This easy mod will expand the capacitance of a hornet back-fire tank, customizable to as much volume as needed.

Ranges are dependent on your own pressure used, and how much you choose to expand the tank. Therefore, I won't be offering any review concerning ranges, but logically more discharge capacity can support a longer barrel, and provide more acceleration.

Part I: capacity expansion (holding pressure and firing)
Part II: output expansion (not holding pressure)

Part I materials required:

3/4” PVC threaded tee
3/4” threaded plug
Teflon tape
PVC glue and primer (epoxy might also work, but the PVC glue is nice and gooey for filling gaps and air tight proven in my prototype)
3/4”x1/2” CPVC reducer (if you are using a CPVC barrel)

Optional:
3/4” threaded nipple (optional if you want to expand it beyond what the plug will hold)
3/4” threaded cap (optional (to cap the nipple))
3/4” ball valve (very optional) (placing a valve midway down the nipple will create a third expansion usable mid war.

Part II requires a Bic pen (and cap)
3/8" drill bit (equal to a Bic pen cap outside diameter)
epoxy
pipe cutter
e-tape
1" pipe clamp
3" clamp
(clamps and tape are to form a temporary seal for testing)

Tools needed:
Heat gun (glorified hair dryer) or torch (preferably heat gun. Much more controlled) I got mine for 13$ new at Harbor Freight (a discount tool chain. Love that place!) probably 20$ish everywhere else.
Dremmel with spiral cutting bit, or drill press with 1/2” drill bit (preferably a Forestner type bit. It cuts a little more shallow)
Canned air/air compressor with spray nozzle

Time:
Less than an hour (+glue setting time)

Start by disassembling a hornet and getting to a bare tank. This is already covered in other posts, so I'll assume yourself capable of using the search function if you have questions.

Lop off one of the side legs of your tee level with the middle leg.

Here's the exploded view of what you'll be doing.


Insert your threaded plug to keep it from stretching out of round. (hand tighten to snug fit. You don't want to stretch the threads once it's heated)

Heat the PVC tee with a heat gun until it becomes shiny (it will be in a slightly mailable state)
Please don't burn yourself. Heat guns put off some serious heat.

Once it's shiny, stuff your hornet tank in through the leg you shortened until about 1/8” of the tank is sticking out the back. Re-heat and stuff your CPVC reducer into the barrel end (if you're using a CPVC barrel)
You can see how it's stretched and slightly deformed.


Allow to cool slightly, unscrew the plug and look to make sure the shoulder of the reducing section is past the hole of the the threaded leg.

Remove the tank and reducer. I had to use a rubber mallet. If it's really tight, re-heat then remove.

Fit test the tank and CPVC reducer into the tee once cooled. If every thing looks good, apply PVC primer to the inside of the tank (not the threads) and hornet tank. I realize it might not be the perfect chemical match for the plastic of the hornet tank, but we at least know it's appropriate for the PVC. Next apply PVC glue to both the tank and tee. Goop the heck out of it. We'll need it to be completely covered and air tight. Stuff the tank in, and rotate it 360 degrees to ensure the glue makes complete contact with all sides. Don't glue the reducer in. that will probably hold on it's own, and you may want to fill dead space later. Set it down with the plug pointing up and let it dry.

Once dry, remove the plug, and Dremmel out/drill out the shell of the hornet tank visible inside the threaded tee portion.

Don't drill any deeper than you absolutely need too. There is a peg with a piston on the end centered in the tank. You don't want to damage the rubber fitting on the end.

Be obsessive about cleaning out the shavings. Rinse it out with water, then use canned air or an air compressor to blow it out. Shoot air through a straw down the barrel nozzle. Get them all gone. Even one particle can hinder a seal.

Apply Teflon tape around the threads of your plug, and screw it in. You'll want a tighter than hand tight fit this time. (or until it stops leaking...)

Pump it up and test fire.

If you want more capacity than the plug holds, just screw in a nipple with a cap on the end.

If you want a mid-war expandable tank, just glue a ball valve in the middle of the nipple. Just slap on a coupled barrel extension to increase barrel length, and turn the valve to expand tank capacity to match, pump more and fire at an increased range.

Theoretically, you could create a hornet tank with more capacity than a titan if you wanted!

Part II:
My incomplete airflow expansion: (Piston won't seal and hold pressure. Grrr.)

If you wanted to completely open the shell to try to enlarge the output nozzle for increased air flow, use a pipe cutter to gently get a channel set before applying pressure and cutting. This heat – stuff – glue method could be used to mate both halves back together. Though, I'm just e-taping, pipe clamping both halves together with a C clamp to hold both halves together laterally to test and trouble shoot. (E-tape and a pipe clamp didn't hold. the halves separated, and one half shot across the room. It took me 3 weeks to find the piston.) Don't glue it till you know it's capable of holding a seal. Mine still is not sealing. I drilled out the barrel side nipple, and epoxied a Bic pen cap in it's place the cap is too wide for the piston to seal on, but the cap lets you nest an adjustable Bic pen tube inside.)) If anyone else wants to give it a try, have at it. At the very least, I'm open to suggestions.

Pics of internals (because I haven't seen any on Nerfhaven)


barrel side peg, and supports partially drilled out to be replaced with Bic pen cap section at right.


cap prep


cap being epoxied into place (pen tube inserted to help make sure it's going in squarely)


Taped and clamped for a test fire. (leaks out barrel. still a work in progress)


Any thoughts?
I haven't looked into it, but I've been wondering if the same heat – stuff - glue - drill method could be applied to increase the output capacity on a RF-20 piston...

Great build! Back pressure tanks have always fascinated me and I've dissected every model of that style that I could get my hands on. I've also tried building my own but failed to produce anything functional. I did learn that the output hole to your barrel needs to remain a smaller diameter than the ID of the inlet hole. If the outlet hole is bigger, the piston wont move. I'm not sure if that's even possible with your design, but it might be a useful bit of knowledge for anyone trying to get too greedy with the output hole size.

Spontaneity seems to play a big role in developing memorable game types here in Utah. One silly spark of an idea during a game of CTF came when someone wondered what would happen if there was only one flag. The game morphed into "deathball" where both teams are fighting for control over the single flag and are trying to push it into the opposing teams territory.

 

Another memorable moment occurred when one participant brought an inflatable t-rex suit to a war. An unforgettable game called "Tim is an invincible dinosaur with a marauder ax, run for your lives!" was born from that stroke of brilliance... I don't think that game type needs much explanation...

 

I guess my contribution to the discussion is that we shouldn't be so distracted with having structure and rules that you miss out on making the really memorable moments of an event.   

 

I've also appreciated So-Cal's speed round (where a line forms on a small field and 2 enter for 1v1 winner stays, then 2 go to take on the winning team, then 3 then 4...) it gives those who aren't loading up their dozen mags something quick and fun to focus on while the few heavy gunners mobilizes the communitys entire ammo bin into mags (of which they'll only empty 3 but whatevs)...

Crayola barrels were popular because they get a little tighter towards the back of the barrel. Before you get too crazy you may want to make sure your darts will pass through the entirety of the barrel. If needs be you might be able to drill that restriction out since pump powered blasters tend to perform better with looser fitting barrels.

I'll occasionally throw a 35 round drum in my ar removed ls when I get the silly urge to spam darts.

It is interesting to note that so far most nerf brand blasters being used are air techs and older. I expect to see some saying they use nf's in pistol rounds, or maybe a stampede as a primary... Could that mean nerf is loosing its competitive edge for modding? It wasn't until reading this thread that I realized how heavily I relied on off brands like Buzz bee, lanard, ertl, and more recently marshmallow shooters as base components for my blasters.

Wow. I think that's a necro that's worth a re-read. I'm actually kinda intriuged with the bug sprayer tank option (provided it's clean and clear of chemicals). They're large capacity and are built and designed with pump and suitable oprv. They'll weigh a lot less than any metal hard tank as well. I think they would be crazy cheap and easy to dump in a backpack and run with... I wonder what pressure the oprv pops at...

You might also want to consider a side mounted thumb trigger for the secondary valve.

If you can forgive some brutal honesty, you're asking us how to put lipstick on a pig. The Deploy is widly regarded as one of the worst and poorest performing mag fed blasters ever produced. It's a gimmicky useless mess with a tiny plunger tube and shoddy internals. You would be best served by starting a local wall of shame and leading with your deploy. Heck, even a recon would be a better option so far as reliability is concerned. A raider/retialator would be even better.

I believe most people don't run stock Stryfes at more than 3s, using Ultrafires. I'm sure LiPo or NiCd or something would be fine, too, stock motors can't have that much current draw, even at stall.

I run 4 trustfires in my N-strike Rayven (stock motors), have for a few years without burning them out - granted I only rev it up just before firing and let off motors the instant I'm done. I also recharge the batteries after every war it sees use.

Cool. It's a vindication for those of us who save everything - just because it might be useful some day.

I didn't see it covered (sorry if I missed it) but how much does each completed dart weigh? Gumdrops are light weights at only .5g. I wish they were a little heavier - though they can still break 100' with a powerful enough blaster.

I can see challenges when it comes to mass producing them - unless you have 3 or 4 rf 20s with ar s to harvest, it would take a lot of mavs to produce a couple hundred darts for a war. Regardless though, its a great use for a much hated part. Kudos!

I think this thread deserves documentation of my "auto blanker".





The back cam stops the foam - measuring the length as the front cam (with attached razor blade) spins around and cuts it. A wet-dry vac provides suction that feeds the foam. In the full speed operation video it cuts 100' of foam in 3min 44 seconds - though the drill battery was almost dead at that point in the night. With a full battery on low gear (high gear makes it jam up) it cut 100' in a little over 2 min.

Slow operation video (click to view):


Full speed operation video (click to view)... Photo bucket refuses to let me upload over my current slow internet connection. I'll have to get it up once I get back to a more stable connection.


Ends come up perfectly square, length is incredibly consistent. It's a beautiful result!

Write up is pending - but coming. Right now I'm focusing on the production and sale of cut blanks. (Shameless plug warning)
pre cut beige foam sale link

Visual tracking has a whole other host of complications. The camera has to be able to recognize and follow the dart, the accuracy would be limited by frame rate and recognition.

 

Theirs another direction I'd like to suggest for this problem. Acoustic emission and Ultrasonic time of flight.

 

I work in NDT (non destructive testing) and specific technologies exists to track the active progression of cracking and erosion in pressure vessels is Acoustic emission. It basically involves epoxying multiple microphones onto a surface and listening for the object to make noise and then triangulating the location of the noise by recording the time it took between each microphone to pick it up. I'm told the industry was pushing the technology pretty hard in the late 90's but it never really took off because it was so specific in it's use. You had to know a crack was present before you would bother listening for it. Acoustic emmision is a spin off of Ultrasonic testing. Ultrasonic testing uses a transmitter to induce an ultra sonic sound into the wall of a part and times how long it takes for that signal to travel to the end of the wall and bounce back to the transmitter. It can measure thicknesses down to the .001" of an inch and is widely used in the industry today. (especially in the medical industry). 

 

Instead of a complicated video set up, maybe 3 microphones and some slick programming can duplicate the same result? If professionals can "listen" to a crack growing in a vessel, maybe we can track and plot the location of a thud on a dry erase board with a few piezo electric elements? Heck, we could even add a fourth element onto a blaster barrel attachment and pull a fps by knowing the distance between the blaster and the white board and timing the travel between the first thud (blaster firing) and second thud (dart hitting the board). Knowing the actual time of flight between barrel and board would also measure dart drag. Most of our chrony values are measured at the barrel (where we can reliably hit the chrony window), which is great for grading a blaster, but poor for grading a dart. Knowing time of dart flight would introduce a whole new way to grade actual and specific dart performance beyond accuracy. 

 

Such a set up could even keep up with blasters in full auto mode and plot data instantly. 

 

Sound travels through different materials at different speeds so there would need to be some calibrating involved, but that would be as simple as "thudding" the board next to one microphone and carefully measuring the distance and time to another mic. Once we establish that sound travels [x] fps in what ever material is being used, the rest is programming and math. 

 

Sound waves also bounce inside solid materials so there might need to be some sensitivity adjustments or sound deadening channels behind each microphone as well. 

 

Edit: : Might be needing to use trilateration (not triangulation) since trilateration also involves distances from known reference points. Wikipedia refference:

https://en.wikipedia...i/Trilateration

I should have clarified, when I was talking about differentiating air sound from board sound, I was talking about sound of dart hitting board travelling through air vs. sound of dart hitting board travelling through board. Not sound of blaster vs. sound of dart impact, those two spike will be miles away at the scale we are considering. If your SOS through the board is close to that through air, you are going to have real problems differentiating the two unless the peaks of the spikes are sufficiently different i.e. different volume.

 

What I'm advocating is measuring sound of dart hitting the board through air with a sufficiently high SOS board material.

 

Ah, Thanks for clarifying. That makes a lot more sense. I guess I'm so hardwired into the theory of ultrasonic properties, that i had somehow forgotten that sound still travels through air at a constant and measurable rate, and that a dart hitting a board makes a significant sound. It would definitely be easier to go with the much slower velocities of air conduction rather than overhauling hardware for ultrasonic speeds. Measuring through air would also let us pick up the sound of the blaster firing to establish dart speed and drag if we wanted to get the extra data. 

Here's the sound velocities chart from the inside of my clipboard. Obviously, it's not complete but might be helpful as a point of reference for some ball park values. For this project we should probably be looking for slower values, but not so slow that we loose too much volume due to attenuation. I'm attaching it just to show how wildly values can change between materials. And because it's geeky cool. It's always surprised me how much variation there is between materials - and even between metals.

 

Base line: sound traveling through air: only 343 meters per second. Wacky, but sound travels through solids waaaay faster than through air. Hopefully this is still within the realm of an arduino.

 

Of the values listed, Plexiglas might be our best bet with a pretty reasonable 2800 meters per second. I'm still curious about the viability of MDF/pressboard/dry erase board (because of cost) but theirs a very real chance that the pressed construction of the material might fail to transmit sound at a reasonable distance. Plexiglas is also tempting because epoxy resin is also 2800 meters per second. The identical transmission speed should be crazy helpful getting sound from the board into the probes. The bigger the difference in transmission speeds, the more loss there is as it passes through boundaries.

 

In respects of differentiating between a pulse from the blaster firing to the dart hitting the board, it's not something we will probably have to worry about. As sound is passed from air into a medium most of it is reflected back instead of being absorbed into the part. Even with ultrasonic couplant (a specialized jelly with the viscosity of snot - which also works as a couplant (it was cold, i ran out of couplant, had 2 readings left and was NOT going to climb back to the top of that 85' tower!) only 11% of the energy from an ultrasonic transducer actually makes it into the test subject and the other 89% is reflected back into the transducer. We should be able to do much better with an acoustic driver like a nerf dart smacking into a target and shouldn't have to worry at all about the board picking up the sound of the baster firing. Though, holy crap that would be cool if we could! With a carefully measured distance from the blaster to the target, if the board could "hear" the blaster firing, we could use that initial pulse to establish a chronographed measurement of the dart and establish dart drag - without a 4th listening element wired up to the blaster! In all honesty, I think we'll have more trouble with picking up multiple instances of the initial sound wave bouncing back and forth within the sheet  than external interference like ambient noise or blasters firing. 

We should probably be just as picky about the shape of the board as the material. It's a rough sketch, but if we have something like this, we might be able to tune the shape of the board so reflected sound waves are only hitting the probes once and most of the secondary waves are either reflected away from the probes, or are absorbed behind the probes.

 

 

Even though the math, science and technical level is well above my experience level, at least I can google. Here's some ground work discussion already laid by others...

 

https://forum.sparkf...hp?f=14&t=24738

 

https://electronics....ection-position

 

https://playground.a...n/Triangulation

 

https://en.wikipedia...i/Trilateration

If you're doubting your chrony why not test it against the calibrated standard of gravity? All falling things accelerate at 32.2 feet per second (minus drag) so why not drop something dense and smooth surfaced (like a marble, ball bearing or heck, even a roundish rock might work) from a measured distance and compare the measured speed with the calculated speed?

 

We (the collective NIC) might even want to develop and accept our own standard to test and compare our chronys for accuracy. It'd be as simple as "drop a dense roundish object through it from a measured distance of 4'.  "? That's a test all chrony owners can perform without having to ship anything anywhere.

Welcome back. It's great to see people coming back to the hobby. There really hasn't been too much to replace quadshot'esque classics primary wise.

Many of the recent releases have had smaller plunger tubes, gears that strip and other devices that kill the quest for more power. The smart AR system (Ruff Cut, Triad, Zombie cross bow) has been one of the newer devices. Multiple barrels are linked via an air path and the AR's are used as valves. If held back by a dart - it fires, if the barrel is empty, the AR shuts that barrel off and air moves to the next barrel. Cool technology, but send more than a stock amount of air to the system and multiple darts poop out instead. Nerf has also tried to feed us a massive steaming pile of plastic called the centurion. We all had such high hopes for that thing, but the dart shredding breech and massive venting slits in the plunger tube have killed any potential there.

Buzzbee had an awesome little pistol out for a while called the panther. It was about $7 and had the power of a 2k. They quickly realized their mistake and switched to tanks half that size, then built a whole line around the smaller tank. Many nerfers hoarded the full-tank pistol, you should be able to pick one of them up without too much trouble.

With the recent regression of stock blaster potential homemades have really started to dominate the field. It's not an area I've gotten into, but I can definitely see the NIC leaning towards them for salvation.

I had once considered finding a paint/filtered eyeglass lens combo that would make darts pop out like they were glowing. I never was able to find anything though.

I tried mass spray painting darts to mark them for a mass war - It was awful! Paint transfered from darts to barrels and hands, and then from hands to blasters. It took me quite a while to get blasters back to a normal working order - some of the worse ones (maverics) never recovered.

Perhaps dye instead of paint could be found, but I think titanium2 might be on to something. Marking the tails would be like raising a "find me flag" with every shot. My first attempt at darts included a bright neon disc (ear plug foam) glued to the tail. The darts were awful but recovery was great. I bet craft foam would be a good substitute. Hot gluing them on the tail would throw off your center of gravity and make the dart unstable. You would want to switch to a lighter glue. 3M makes several spray adhesives that could work. Application would be quick that way too - you could spray several discs at once and touch a tail to them to complete them.

The only review on amazon says their stryfe flywheels can't grab the pointy tip. Racer, could you see if they work in a flywheel blaster?

Just realized the [TaerKittys tetrahedral monsticle pics]pictures don't work. Dang, it was a really easy to follow guide, but I'm sure you could find references elsewhere.

Sadly and tragically ALL of Taer's pics from almost every write-up were lost when he tried futzing with the site he was hosting them from. So much fugly lost...

Brilliant. That should be a standard accessory for every range test performed!

How's the spin up time compared to our usual modified motors? Does this grant any boost to ROF?

I couldn't see the broken part in your picture, I'm gussing you're referring to the tab on the slide that holds the pin in place? That's the most common break on a mav. Here's two options:

fix with nail That's about what I've done to repair mine when they break - only with a bit of coat hanger instead of a nail.

and:

cocking handle repair with beefy steel bracket.

Hobby and model stores are a good bet. Especially places that specialize in model trains. A phone call will save you some driving. Good luck.

1st edition panthers. They're a small pistol with a decent internal air tank. Later editions were neutered with smaller tanks. Look inside the barrel. If the barrel id is black, put it back. if the barrel ID is white, it's right. I put a 3 dart RSCB on mine and it's my favorite NIC primary due to it's super small size and decent power.

I've tried spray painting my darts to simply mark them as my own. It was a pretty big disaster with paint transferring to barrels and gumming them up. Half the blasters in my arsenal had to have darts physically pulled out with pliers. It was like they were glued in.

Fluorescent paint could be a pretty helpful way to do an after hours dart sweep if you have a battery powered blacklight/flashlight. It's a very cool idea though. I bet some laser tag arenas would let you rent the place out for a nerf war and it would rock to see the darts flying around!

Let me know if you have any of the paint adhesion issues I had?

You could anchor a bit of surgical tubing from the bolt sled to the shell so it automatically closes itself when the priming bar is released in the open position(much like a real semi-automatic rifle).

I once heard Just Some Bob mention that he thickened the ID of a barrel using repeated coats of floor wax. (though I haven't tried it)

I'm reluctant to give noobs clip fed's - even if they still have the locks in. They'll always find a way to jam it up. My go-to loaners are ruff cuts. They're impossible to screw up... "Darts go here, prime here, squeeze trigger fully to shoot both sides...." You still get 8 shots, they're easy to keep fed and they have decent stock range.