Zombie Lachesis

[Myrkul]

I have felt for quite some time now that the Indian Creek Designs Bushmaster 2000 is the single most under valued marker that has ever graced the game. Yes they are old, and tired, and beat. They originally were released in the fall of 98, so that's to be expected on a 25 + year old marker, but they almost universally clean up really well, and they shoot absolutely amazingly after appropriate amounts of elbow grease have been applied. I've been meaning to do a write up on them for quite a while now, and since this build is going to fall well within the budget outlined by the rules, I figured I could kill two birds with one stone by entering it in the build off. The biggest risk of also entering the build off is that two months time constraint, but I'll work as fast as I can.

So here it is. It was purchased as part of a larger deal, and when the dust settled, this ended up running me $70. Please note, the solenoid gasket is missing, which is what makes this a zombie and essentially "dead".



It is completely checkered in idiot marks, gouges, and scratches. My kind of project, since all those little love taps just mean that A: Someone thought it shot good enough to be worth fixing, despite not knowing how. B: A few more drunk idiot marks aren't going to impact value or even be noticed, and it helps the price a ton, so I'm all for it. C: Parts lottery. It's been worked on, which means there is a good chance some upgrades have snuck their way into it. Just on its face, there is a vert ASA adapter in there, so I'll be able to run an aftermarket HPR, AND that's a 2k4 board in the grip frame (more on this later).

Due to my undying love and admiration of the platform, I also happen to have a considerable amount of parts on hand that were bought in bulk for other projects and never used. I think these should complement the final build VERY well.


If you look close, that's a true ICD threaded CCM no-pro. Lots of people claim that Empire/Impulse threaded feed necks fit bushmasters, and while they can work, the threads are typically just a hair thinner so you run the risk of stripping out either the feedneck or the body with them. I exclusively run rotors on these things, so I'm not going to take those chances and will be using the correct feed neck for this gun. If you can't find a true ICD threaded feedneck for your gun, have a machinist chop the stock feedneck down into a empire stub. That way, the threads are for sure the correct thickness and you can still run any clamping feed neck you want on it. Also notice that little red part. That's a Shocktech LPR piston. We'll dive into that when we get to step 3.

I'll also make a note when I pull something else from my parts bin, which has blossomed into a truly wondrous cornucopia lately. I have all the regular ass "o" rings on hand for this build, so just assume those are being replaced, but if I end up using something weird to clean up the tolerances a little I'll call it out. Same goes for screws. Years of buying just a few extra incase I loose one has left me with quite the surplus.

So here is the game plan.

Step 1: Disassembled and clean everything, track down missing parts.

Step 2: Refurbish the Valve

Step 3: Mod the Stock LPR

Step 4: Rebuild the ram

Step 5: Sorting out the Electronics

Step 6: Cleaning up the breach

Step 7: Trigger Job

Step 8: Assembly and test firing.

We'll see how all of this goes, as mentioned earlier time is very much my enemy here, there is a LOT of work to be done, but we will see how it goes.

[Myrkul]

Step 1:

Since it was mostly there already, I finished tearing everything down. Hot water and dish soap on everything not electrical. I scoured Facebook for a bit and in a stroke of luck I still cannot believe, a large and well known ICD collector needed help refinishing a Pro-Carbine for non-lethal home defense. I had a full pro-carbine rebuild kit laying around from when I rebuilt my dad's a few years ago, so I was more then happy to pass along the parts, and he was more then happy to pass along the missing solenoid gasket.


I mean I did have a spare gasket anyway, but it felt better to grab another one for this build and not deplete the parts bin any more then absolutely necessary, especially since there was a slim to zero chance I was going to need the Pro-carbine rebuild kit anytime in the next 15 years. So that completes step 1: this fucker now has the potential to be "undead" instead of just a paper weight!

Just as an FYI to anyone else with this specific issue, Impulse and Shocker 4x4 solenoid gaskets are identical to B2K solenoid gaskets, so those are options if you need to track one down. Just be gentle, cover them in super lube multipurpose grease, and make sure the solenoid is screwed in tight and they'll keep running just fine despite their age.

[Myrkul]

Step 2: Refurbishing the Valve

Most of the time, this isn't a step. Valves should work and keep working. Occasionally you should replace the #016 "o" rings with fresh ones (both 70 & 90 durometer work) but that should be the long and short of it.

That was NOT the case here. While the cup seal looked absolutely fine, the valve itself was beat to absolute shit. I have never seen a valve face this mutilated before in my life.


No way that is holding air, but fortunately, it's a fixable problem.

Just sand it out. Since it's a valve face, extra care should be taken when sanding it. I like to start at 600 grit in these situations, then move up to 1000, 1500, 2000, 2500, and then clean with a combination of Flitz dumped on a chunk of never dull, then cleaned with copious amounts of paper towel, THEN cleaned with dish soap and water. There are a few different methods for getting the face perfect, but I've always had the best results using a plexiglass backer and holding the valve itself perfectly straight and flush to the plexiglass, and rotating the sand paper in a circle around the valve. In my brain at least, this means the sand paper creates circular micro ridges (a ring of walls) in the valve that help prevent the air from escaping. My brain might be wrong, but it usually works*. I typically spin it both clockwise and counter clockwise just to ensure it's as smooth as possible from every angle.



After a considerable amount of elbow grease, I think this cleaned up pretty well.


I definitely think it will hold air now at any rate. As before mentioned, the cup seal actually looked fine here (possibly an attempted fix from the prior owner?) I did disassemble it and give the valve stem the 600-2500 plus Flitz & Never Dull treatment as well. Just used a hand drill and threw the stem into the chuck, then re-assembled with blue loctite on the threads. Also threw a q-tip into the drill chuck, covered it in Flitz, and ran it a bunch inside the valve where the pin made contact just to ensure there weren't any burs, dents or scratches (I've seen it happen before....).



So that concludes step 2. Valve should be good to go now.

Just as an additional note, if the cup seal had been bad, ICD still stocks cup seals because it's the exact same seal as their lever charger uses. ICD Gary recently sent me a massive bag of them for unrelated projects.

*This method has worked for me on numerous valves, from Spyders to Tippmanns to Nelson pumps to electronic Bushmasters. If you want to be adventurous and replace the cup seal you can't find with a nylon washer from ACE, you can absolutely do so, but remember that the harder the material the more perfect the valve face has to be and the higher pressure you have to run.

[lhamilton1807]

It’s interesting that you’re running your face polishing in circles. Maybe you’re better than I would be at moving your hand in perfect circles, it I doubt you’re getting micro-grooves cut into the face. When getting a mirror polish on old processors, we always used a figure 8 pattern to ensure all angles were evenly applied. The higher the polish on the CPU lid surface, the better it would transfer heat to the heatsink.

I have a valve that needs this done, and I’m glad someone else has proven that they can be repaired.

[waffles2]

Your love for these guns has inspired me to tackled one as a project gun this year. I need to see for myself if they’re really that good. Need to finish my impulse project first…

[Myrkul]

Do it! I like these WAY more then impulses. They are thinner, shorter, smaller, & lighter then impulses. Once they are all dialed in they feel quite a bit more refined then an impulse does. They can be a little bit trickier to work on and aren't quite as robust though.

[OpusX]

[Snowpuff]

Is this for the same bushmaster ?

[Myrkul]

Well it does say "for Bushmaster/Defiant" so I'd assume so. I've never seen a warp feed on a bushmaster before, that's a pretty nifty part!

[BrickHaus]

This is one of them parts you buy the rest of the gun to build around.

[Myrkul]

Step 3: Mod the Stock LPR

So ICD regulators have a somewhat deserved reputation of being....well just not great. Typically most people just pull them off almost immediately and throw on anything else they can get their hands on. Back in the day, PPS was typically regarded as the best LPR, followed by the MacDev LPR, followed by the AKA LPR which is still available today and in stock on AKA's website.

Eventually I got tired of shelling out $70 for an LPR every time I grabbed a B2k, so I did a bunch of digging and asking around, and as a result, I have finally managed to get some really solid performance out of the stock LPRs, but it takes some work since there are two big issues we need to fix with them.

Issue number one is the airflow. The entire ram and solenoid assembly on a bushmaster is fed though that tiny little slot at the very end of the threads:


Making matters even worse, the LPR feeds that little slot trough one tiny little 3/32nds hole just past the threads on the LPR.




That's not nearly enough airflow for these things, especially when you really start jumping on the trigger. Making this already bad situation even worse, the tolerances for the threads on the the body itself are pretty loose. I've had B2ks that initially refuse to seal at all from the LPR, or the #016 doesn't seal right and leads to massive amounts of reg creep. I've also had one B2k where if the LPR was screwed in too tight, it would cut off the LPR air to the ram and solenoid entirely. On a different B2k, the air slot on the the body had been poorly cut and there was a huge chunk of metal still attached that I had to carefully file out with a jewelers file. In short, this is probably the biggest "problem area" on the entire marker. Luckily, I have always been able to sort out the tolerance issues by using 90 durometer seals for the #016 & #019 on the outside of the LPR body. That will clear up any leaks at least. You can absolutely get away with 70 durometer most of the time, but it's been a frequent enough problem that I just throw 90 durometer on it now so I don't ever have to worry about it. So that clears up some of the problem, but it doesn't help improve the airflow in this area.

Here is how to fix the airflow issues. I believe this mod was originally Greg Schutte's idea (Yes the same Greg Schutte who made the Bluefork T-1 & T2 frames, the GBR rams, and a number of other really cool paintball parts). Carefully use a punch to mark out where you will be adding 3 additional holes in the LPR body. The spacing isn't overly important, but what is important is that you have them at the same height on the LPR body as the stock hole is. Once you have the hole locations marked, use a punch and a hammer to put a nice little dent there so that there is something for the drill bit to catch on to. This next step is kinda tricky, especially if you don't have the right tools. I used a dremel press & a vise. The dremel press was nice because it let me set the really wonky angle these need to go in at and lock the angle in place, so I just needed to guide the drill bit into the dent. Be absolutely sure you have a sharp drill bit and copious amounts of cutting oil, because drilling into a cylinder at this wonky angle is relatively difficult. I usually use a 1/16" drill bit to run the initial holes, then drill them out to 3/32nds after they are all in place.



The spacing wasn't remotely close to even on this one, but it shouldn't matter since the holes themselves were at the perfect height and angle. Super happy with how this part turned out.





So that clears up the first issues with the stock LPRS.

The second issue with the LPRS is the pistons. Right off the bat, the pistons in B2k LPRs MUST use a 90 durometer #015. If you use a 70 Durometer you are going to be in for a bad time. The original LPR pistons were thin aluminum, and were prone to sticking. After a while ICD switched to the thicker aluminum piston, before eventually settling on a thick white delrin piston in the later models. The white delrin pistons give the best performance of the stock LPR pistons in my experience.



Since the pistons were kind of a known problem area for the B2ks, it turns out shocktech actually made upgraded pistons as well in an effort to correct the issues. I've seen the Shocktech pistons anodized either red or blue, and they are immediately recognizable because they use 2 70 durometer #015 "o" rings instead of a single 90 durometer #015. They work extremely well, and when tested with a gauge the shocktech pistons on a modified LPR body was noticeably more consistent then both the AKA and the MacDev LPRs I tested it against.



For this build I had initially planned on using a spare shocktech piston I had laying around, but upon opening up the LPR I was greeted with both really bad news and really good news. The bad news was that the LPR body had been mauled beyond repair. Not a super big deal, I have a pile of stock LPR bodies because everyone hates them so much, but I was a little miffed that I didn't have any in silver. Oh well, black goes with everything. Now for the good news, parts lottery for the win! I'm not sure exactly who made these LPR internals, but they are definitely not stock and I've never seen internals that look like this before. On top of that, the reg seat itself was in awesome shape and looked very fresh.



Note that even the regulator cup is different, I've only ever seen these made from brass before, never aluminum.



Curiosity got the better of me here, and rather then run the shocktech piston I kinda wanted to see how these did. I cleaned everything up, replaced the #015 "o" ring on the piston, and dumped them into my newly modified LPR body. As a nice finishing touch I went on Ebay and grabbed a new adjuster cap in silver ($15), because it looked cool and this project is still coming in way under budget.



Now that everything was nice and assembled I went ahead and threw this on one of my other b2ks to test it. It works awesome! Probably about on par with an AKA LPR, not quite as good as the shocktech piston, but only by a hair (I did use a gauge to test the consistency). Definitely good enough for me! Set the LPR to 65 PSI (Yes the factory recommends 85-95 psi for the LPR, but running them that high is super unnecessary, I've always found 65 PSI to be the "Sweet spot" for B2k LPRs) and locked it in place with the grub screw.


This concludes step 3.

[scottieb]

You are doing a fantastic job. Following this is great. I feel like I should be paying tuition.

[Myrkul]

My big nefarious plan here is to keep as many of these things out on the field and mowing faces as possible. Yes they take a fair amount of elbow grease to get going perfectly, but I am convinced there is not a better shooting marker out there for the money.

[lhamilton1807]

Subbing because I have a B2K4 rebuild in the works. I’m up for sitting at the feet of the master and learning.

[MrKittyCatMeowFace]

kevin qmto .