The Z FAQ

The term 'Z' actually refers to a family of paintball guns made by Montneel Designs. The family includes the Z-1, Z-2, MZ-16, RENTAL-Z and the Mega-Z. The Z is an open-bolt, blow-back semi- auto, loosely based on the 68-special. The latest Z's are designed to run on SIPHON tanks only (early Z's ran on vapor, plus current Z's can be modified to also run vapor, and nitrogen). The features of the Z include unique barrel lock, breech lock, right-side cocking knob, long range accuracy, rapid firing, low maintenance, durability, cold weather performance, consistent velocity, and a brass-lined, aluminum barrel.

The Montneel Designs Z has long been considered the best blow- back semi on the market. This in not contested. Those who own a Z will argue that its the best overall semi on the market, however it is not my intent to start a debate. For the purpose of this FAQ, I will refer to the different Z-versions simply as "Z", and make note of differences between models and upgrades when they occur. Also, I will assume that the Z is running on a SIPHON.

The Z-1
Current Z-1s come equipped with a SIPHON valve (also called winter valve), which is designed to run a SIPHON tank, in temperatures below 90f degrees. They come with a 11" brass lined, aluminum barrel, locked in place with a set-screw. They have a removable feed-port (2 set screws). The entire breech is also removable (2 set screws). Velocity is adjustable between 190- 330fps, externally (tournament legal). A SIPHON tank is mounted on a back-bottle ASA. Current Z-1s come with an aluminum bolt, right- side cocking knob, and a M-16 Lone-Star grip. This Z-1 has picked up a reputation as the ONLY gun that works in cold weather, and one of the least guns to get a HOT-GUN penalty. There has currently been about 12,000 Z-1's made (by Montneel Designs).

The Mega-Z
The Mega-Z is an upgraded version of the Z-1. The Mega-Z is the same as the Z-1, except that the barrel retaining bolt has been changed to a pull-pin. The two breech retaining bolts have also been changed to one pull-pin. A vertical c/a setup has been added. The bolt has been changed from aluminum to an aluminum Venturi (called StarFire). And a quicker trigger mechanism is added (including quicker sear, and trigger shoe). Currently, the Mega-Z is the third most popular tournament semi (though, far behind the top 2). The Mega-Z is well known for is extremely quick field- stripping (via pull-pins), and rapid fire rate (via trigger upgrade). Also, the StarFire bolt breaks very, very little paint (usually about 1 per 4000). The new trigger makes the VL2000 a must, or it will pinch paint. A Mega-Z can easily shoot 1000 rounds, in 3 minutes, in 30 degrees, WITHOUT A DROP IN VELOCITY, without braking a ball. (I have done it, though, I wouldn't stick my tongue on the gun afterwards). There has currently been about 1100 Mega-Z's made (by Montneel Designs). About 300-400 Z-1's have been upgraded to Mega-Zs (see section 7).

The Rental-Z
The Rental-Z is a special version of the Z-1 that is available only to fields. The Rental-Z is the same as the Z-1 except they come with stainless steel screws, quick-pull pins for the barrel (like the Mega-Z), and feature a red main body with "RENTAL" milled into the side. The RENTAL-Z is a well suited as a rental gun for walk-ons. Not only does it have the high-performance qualities found in the Z-1, but it has also been modified to last the life of the field. The bright red body, with the milled "Rental", might seem tacky, but it would be IMPOSSIBLE for someone to steal the gun. There has currently been around 200 Rental-Z's made.

The MZ-16
The MZ-16 is a M-16 replica (that's actually made from some M- 16 parts), made for military and law enforcement training. It features a 20 round magazine clip, M-16 style sights, T-handle cocking mechanism, M-16 style bayonet lug, and a concealed 7oz tank. The MZ-16 can take a scope, lighting system, and a 37mm M- 203 (gas/flare/grenade launcher) as options. This gun looks and feels "real", so it is only available to military and police training facilities (We'll see about this! -NB). A semi/auto switch is in development. Contact local dealers, or Stress Shot (who markets the MZ-16):

Upgrade History
There were approximately 1000 grey Z-1's manufactured with a welded on feed port. They are currently up to #1157 on the base Z1, which are black in color and have screwed on feed ports. The first few 250 Z-1's had left-side cocking knobs, and vapor-only valves. The first 500 had a matte grey color. The first few 1000 had Nylon bolts, but were replaced with aluminum used in the current model. Though, when a grey Z comes into Montneel for repairs/upgrading, they commonly have to replace parts (with Black ones) because of wear. The grey guns were made of a lesser quality aluminum and with some different process, and that's why they decided to change the name to the Z-2, when the changed the color to black, and improved the manufacturing process. The "Z-2" designator was only used early on for the black guns, but the factory doesn't use this anymore because the name never stuck. All based model guns are now called Z-1s. All part are compatible within the Z-1/2 models.

The original Mega-Z featured a Nylatron bolt. The Nylatron bolt was believed to be better then the earlier Nylon and Aluminum bolts. However, the Nylatron bolt suffered swelling problems (from the high pressure, and the liquid co2). All current Mega-Z comes with a aluminum "Starfire" bolt. It has an open Venturi for liquid, and is supposed to break less paint, cycle faster, shoot farther, and is more accurate. Also newer Mega-Zs have an upgraded trigger housing, made stronger to take the stresses of the rear screw. (earlier Mega-Z rear-screws often come out VERY hard).

2. Brief History of Montneel Designs

Montneel Designs started out by making custom 68-special parts in the early 90's. During this time, the worked on a special paintball gun that would work in all weather, and never break down. When the first gun was released, called the Icon Z-1, it lived up to this claim, and became very popular in the NorthEast where cold weather was a problem. Over the years, they were constantly modifying and improving the design (which led into the Z-2). The Icon Z's were never mass produced, thus, where often very hard to get.

In early 1994, there was a problem. The partners that owned Montneel Design where having a dispute. To make a long story short, the partners split up, both with rights to the design, but only one with rights to the company name. Montneel designs went on to make the Mega-Z, which was a much improved version of the earlier Z's. The partner that split went on to make A LOT of Icon Z copies, including the CheckMate, which was in direct competition with the Mega-Z. However, the CheckMate was a low-quality Mega-Z copy, and was unpopular.

From my point of view, the only REAL Z's are the ones made from Montneel designs. In fact, I purposely did NOT call the Z's, in section 1, 'Icons Zs' because a lot of Z-copies are mistakenly called 'Icons'. This was done to stress that not all Icons are Montneel Z's.

3. The Z Copies

What are Z copies?
As mentioned is section 2, the partner that left Montneel allowed A LOT of people to copy the Z. Because of this, there is A LOT of Z copies on the market. Last time I checked, I noticed close to 8. The main problem with this is that many of these are being advertised as Z-1's (and Icons) by retailers, when they ARE NOT. It is for this very reason that Montneel Designs wholesales to VERY FEW companies. Z copies are usually less expensive (often around $190). Some parts are compatible, but most are not (usually only the barrel). The quality of the Z copies is vary from poor to unusable. Many Z copies suffer from terrible valve problems, uncontrollable velocity problems, horrible efficiency, high ball- breakage, poor accuracy and some CANNOT even run liquid.

How do I recognize a Z copy?
DO NOT BUY A Z COPY (unless its free, in which it might be useful as parts). Now that I have said that, I will point out that it is often hard to tell a Z copy from an original. If you are buying a Z from anywhere that your not sure about, inquire about its authenticity. If you are buying mail-order, inform them that you will report them for mail-fraud if they false advertise a Z-copy as a real Z. If you are at a retailer, check the gun for the side stamp. ALL Montneel Z's have a metal label stamped on the side. The labels will say Z-1, Z-2, or Mega-Z (and some will also say ICON). Plus, -ALL- will say Montneel Designs. If it does not say have it, do not buy it. I have even seen dealers try to sell me a gun, advertised as a Z, without a side-stamp, with them telling me "The Stamp fell off...". Sure... Good one.

Z-copies examples
1. CHECK-MATE

This is a copy of a MEGA-Z. It was actually designed by the partner that left Montneel. No parts are compatible, and it is a very poor design. TASO sells it, and advertises it as an improved Mega-Z. Don't buy it. (~$340) 2. AK-1

PCRI actually rated this gun as a decent Z-1 copy. What they do not say is that it tends to brake after 2 weekends, and suffers from severe valve problems. The barrels are compatible. Don't buy it. (~$250). 3. Under Construction

4. Where can I buy a Z?

If you have looked into buying a Montneel Designs Z-1, or Mega-Z, you probably noticed that they are IMPOSSIBLE to find. Many companies have opted to sell Z copies instead of actual Montneel Z's because they make more money off them. For this reason alone, it's a good idea to call Montneel, and ask them where the closest authorized dealer is. (BTW, Montneel doesn't sell Zs directly to the public). This way you know you are not getting tricked into buying a Z copy (at a Montneel Z price).

The telephone number for Montneel Designs is:

(717)465-9480 The address for Montneel Designs is:

Authorized Dealer List
Under Construction

5. Maintenance

As mentioned before, the Z requires no maintenance. However its still important that the internals stay clean if its to work at its maximum potential. The Z should be disassembled once every month, and cleaned thoroughly.

Disassembly
First, remove the barrel (either by screws, or pull-pin), and clean it well. Second, remove the breech assembly (either by screws or pull-pin). Clean it well. You should never have to remove the feed block, and ball detent unless you pinched a ball, and suspect that shells may be stuck within them. The inside of the breech is somewhat tricky to clean. I use a wet rag, with a string attached, that I pull through the breech.

Reassemble. That's it. However, if you noticed that its difficult to cycle the gun, or if there is a leak, then you should disassembly the main body. This includes: first remove the barrel, and breech assembly. If you have a Mega-Z, loosen the 1/16 brass fitting from the vertical c/a. Second, remove the rear trigger support screw, which will remove the trigger frame. Third, unscrew the 2 screws on the top on the body. This will remove the cycle rod cover. From here, you can remove the internal cycling rod, the bolt, he cocking rod secure pin, then finally the cocking knob. After this, you can now remove the Valve, Hammer, and main spring for cleaning/lubrication.

Velocity Adjustment
All Zs feature an external velocity adjuster, located directly in front of the trigger, below the breech. The Z velocity adjuster modified that flow of gas through the jet, similar to the 68- Special, and PMI3 (bolt). This method is much better then that methods used on other guns (like Spring, Hammer, or Valve Adjustment). To change the velocity, insert a 1/4(?) allen wrench into the adjuster, and turn the screw 'IN' to lower velocity, and 'OUT' to raise it. Typically, one 1/2 turn is about 20fps.

Some important notes: When chronoing your Z, you CANNOT chrono it like other guns. You must chrono while rapid firing to get an accurate reading. This is because the velocity on a Z usually goes up while rapid firing. Most tournaments make special EXCEPTIONS for Zs is this regard. However, if the tournament rule book say "No clearing shots while chronoing", explain to them how a Z works. I am amazed by how many refs do not even know what a Z or a SIPHON tank is......

It is impossible to get a HOT-GUN call if the Z is chronoed properly. Furthermore, once the velocity it set to a desired FPS, you should NEVER have to change it again (regardless of temperature).

6. Trouble-Shooting

Low Velocity
About the only problem that is ever encountered with a Z is low-velocity. Solving velocity problems with a Z is SIMPLE if you follow this check list. (I am assuming that you are running a SIPHON for this check list. See section 7c, and 7d for running a HPA, and vapor).

1. Temperature.
The Z's valve is specially tuned to run LIQUID very efficiently; about 1000-1100 shot from a 20oz. (I get 500 on a stock VM with siphon). When running a SIPHON it is VERY important that the gun stay cold. If the temperature of the gun rises above 88f degrees, velocity will drop because the liquid in the valve will turn to vapor. Even if the air is above 88f degrees, it is possible to keep the gun below that temperature. Here are some simple tricks to keeping velocity up (in hot weather).

1- A good trick is push the cocking rod forward when screwing on a SIPHON tank. This will hold the VALVE open and cause liquid co2 to rush out everywhere. Do this for about 2 seconds. This will cause the Z to become VERY cold, and should bring velocity up to normal.

2- If your tank is already on, dry fire about 20-30 quick shots. This usually will cool the Z down sufficiently.

3- Some days, the temperature will be so hot, that all the liquid in the bottle will turn to vapor. It will be like running a non-Siphon bottle. This is when its most important to keep the Z cold. DO NOT KEEP THE Z in the direct sunlight. I keep a bag of ICE on my Z on a hot day, between games, and my velocity stays fine. (It ironic that some mag owners put HEATPADS on their guns in the WINTER). If the previous methods do not help, here are some slightly more complicated methods:

1- If you are using a remote, or even a bottom line, take them off. They make it difficult for liquid to get to get into the valve, keeping the Z from "Running Liquid". A siphon tank should only be run from a back bottle (and vertical on the Mega-Z). Naturally, this doesn't apply to a vapor, or HPA.

2- You may have a bad spring. A good test for this is to take the MAIN spring out of the Z. Then, roll the spring over a flat surface to see if the spring "wobbles", or rolls crooked. If it does, than it has probably lost its SPRING TENSION. If this is the case, call Montneel and have them send you a new SPRING.

3- Perhaps your MAIN spring is fine, but its just to weak. You can have Montneel send you extra-stiff, and extra-week springs to help adjust velocity in extreme temperature. Also, the valve spring can be interchanged with nelson-style valve spring. A lighter valve-spring will increase velocity, while a stiffer valve-spring would lower it.

4- There is a rare chance that the velocity problems might be the result of a BAD SIPHON tank. You get a bad SIPHON tank if the siphon tube inside the tank has become broken. Its rather difficult to take the VALVE off the tank, instead, here is an easier way to see if you SIPHON tank is bad: Get a full tank, and screw it into your Z. Fire (with out paint) 40-50 rounds straight up. Then, fire 40-50 rounds straight down. If you only get a nice CO2 cloud when shooting UP, your tank is fine. If you only get a nice CO2 cloud when shooting DOWN, your tank is broken. If you get a CO2 when shooting both ways, then the weather is probably much to humid for a good test. The tank can be fixed by simply getting a new siphon valve. However, have your local air-smith install it, because co2 tanks can become dangerous if the valve is improperly installed.

5- If all else fails, Montneel makes special Z valves for such an occasion. For HOT weather (above 88 degrees), Montneel makes a special "SUMMER" valve. The Summer valve has a redesigned cup-seat, spring, and gas-ports. With this valve, you will get 300fps+ in the hottest conditions. However, efficiency is sacrificed, and should only be used when the WINTER (standard) valve wont suffice. Frame Splitting
This occurs when it appears that the main body of the Z is splitting of from the trigger frame. This is caused when the velocity screw is turned OUT to far, causing to body/breech, and the trigger frame to 'Push' away from each other.

Basically, if you can see a space between your body, and the trigger frame, then you have turned the velocity screw out to much. Otherwise, you will find it extremely hard to take out the rear trigger-frame screw. In fact, it is likely that you will strip it. Furthermore, you may damage the velocity screw, gas-line, and the trigger frame. What if my Z is broken?
Although the Z is probably the most durable paintgun on the planet, it is not indestructible. If anything is wrong with the gun, call Montneel. I have called them on many occasions, and they are very helpful and courteous. Often, problems with the Z can be fixed easily and simply, without having to send the gun in. However, if you do decide to send the gun in, its still a good idea to call them first. Often, they will ask for a code to be written on the side of the box, so that the package gets directed to repairs once they receive it at the factory. This way, the gun usually gets sent out the same day as they receive it.

7. Aftermarket Stuff

The Z is by far the best paintball gun out-of-the-box. For this reason, it doesn't need to be upgraded for any reason. However, for those of you who feel the need to do "something" to the gun (like me), here is a few things you can do.

The Mega-Upgrade
If you send your Z-1/Z-2 to Montneel designs, they will turn it into a Mega-Z for $250. This is the single best thing you can do to your Z-1. After the conversion, the gun will be exactly like a MEGA-Z.

However, if some of you do not want the whole upgrade, Montneel can do any 'partial' upgrade that you want. This would include any combination of:

8. Anodizing (including SPLASH)

Barrels
Like any gun, there is a million barrels available for the Z. However, most aftermarket barrels do not fit properly because of the unique barrel-lock on the Z. Both the J$J and SP barrels tend to slight out while playing. The only aftermarket barrel that I can recommend are the ones made by BOA.

Montneel markets the B.O.A. line of barrels through a dealer network. The stock barrels are VERY good, but the chromed BOA's are slightly better. They are available in straight rifling, with a muzzle break, and "Concealer" which has a built in silencer.

Bolt
There is an aftermarket Venturi bolt available (other then the Starfire), sold by various companies. Its a good replacement for the Delrin Z-1 bolt, the aluminum Z-2 bolt and the early Nylatron Mega-Z bolt. However, if you have the StarFire bolt, stick with it.

Cosmetics
Montneel Custom Anodizing recommendation (for those of use who bought the stock black/grey version):

$100 - 1 color
$125 - 2 color splash
$200 - 3 color splash
This is where I had my Mega-Z 'splashed'. They did a very nice job.

Stocks/Grips
For those who run their bottle in the vertical (Mega-Zs), a stock is a good idea. For a Mega-Z, stock can be divided into 2 different categories:

Both stocks work very nicely. However, stocks that attach to the rear ASA sit about 6 inches higher then the grip-stock, and may interfere with your mask (no more than a back-bottle would). Smart Parts makes an excellent adjustable ASA stock (designed for Mags, but who cares?). The grip-stocks are nearly as sturdy as the asa- stocks, but are much more comfortable to use (IMHO). Plus, some grip-stocks would allow you to run dual-bottles.

Also, the Z can use any aftermarket grip designed to replace the M-16 grip. This includes Ram-Line, 'Euro-Style', and .45 grips. The Ram-Line and Eurostyle grips can not use a standard M- 16 grip stock. In fact, finding a grip-stock to fit these grips might be difficult. Although the .45 is also not compatible with M-16 grip-stocks, it is compatible with the grips that the mag/cocker uses. Thus, it can take any aftermarket option that they can (including a WIDE variety of stocks). Plus, .45 grips are compatible with -REAL- .45 grips, and will take a variety of molded 'battle' grips.

Miscellaneous
The Z can fire extremely fast (especially the Mega-Z). You will most likely pinch balls with a standard bulk-feeder. A motorized loader is a must. Both the VL-1000, 2000, 3000, and "Shredder" are great upgrades.

A quick-reference sight, like a point-sight is a good idea. Weather you will benefit from one depends on your style of play. If you are a 'Hoser', you would probably never use one. However, if you are a stealthy player, Sniper, or 'Turkey Hunter', you may find your self relying on one. I personally use the ADCO square shooter. It has an immense field of view, and fits my style of play. BTW, don't get a scope. You will never use it, and no paintball gun is accurate enough to make use of -any- 2x+ scope.

8. What is a SIPHON tank?

Well, let's first look at a regular CO2 tank (which I often call VAPOR tanks). Inside a full 20oz bottle is 20 ounces of pressurized LIQUID co2 (thus the name). Also in the bottle is pressurized co2 GAS (or vapor) that fills up the space that the LIQUID does not occupy. This GAS is at about 500-1200 psi.

In a regular paintgun, (that uses a regular tank), it uses the pressure of the co2 GAS to fire the ball, cycle, etc. Every time the gun is fired, gas is taken out of the tank, and the LIQUID co2 boils (by absorbing heat) to replace the co2 GAS that was expelled.

The biggest problem with co2 gas is that the pressure varies so much. Normally, a full tank is at about 1100psi. However, is cold weather, the pressure becomes much lower. Also, when rapid firing, the tank has to absorb a lot of heat to boil the liquid co2, so that it can replace the lost co2 gas, as a result the tank gets VERY cold (like when you empty a tank at the fill-station). When the tank gets cold, the pressure inside the tank drops, and that's when the paintgun looses velocity and operating pressure. This is why regular paintguns malfunction in the winter, have inconsistent velocity, and can NOT sustain rapid-fire for long periods of time.

A siphon tank is basically the same as a regular tank, EXCEPT is has a 'siphon' in it. Basically, there is a weighted, flexible tube, that goes from the tank's valve, to the bottom of the bottle. SO, instead of co2 GAS coming out of the tank, LIQUID co2 comes out (exactly like a fill station).

A siphon tank works via that fact that LIQUID co2 doesn't expand or change density until it fires from the valve. No matter how cold the gun gets from rapid firing, the liquid will flow just as well. Liquid co2 will never make broad density changes like gas, until it converts to a gaseous state as it propels the ball.

So, basically a GAS tank works on pressure, while a SIPHON tank works on volume/density. This gives a GUN that uses a SIPHON tank some unique advantages over one that doesn't. For example:

However, using a SIPHON tank does have some disadvantages:

What is ANTI-SIPHON tank?
This tends to cause a lot of confusion. As mentioned above, a SIPHON tank is designed so that liquid co2 purposely comes out of the tank, when the valve is opened. However, an Anti-Siphon tank is designed to prevent liquid from coming out of a tank.

Basically, an ANTI-SIPHON tank is the exact same thing as a REGULAR tank. Typically, paintguns that CANNOT use liquid, use an ANTI- SIPHON tank when they run a bottle in the horizontal position, where liquid might accidentally enter the gun. Since the Z is designed to run liquid, you should NEVER buy an ANTI-SIPHON tank.

Can I use a Reg/Expansion Chamber?
If you are using a SIPHON tank (as 99% of Z owners do), then you CAN NOT use a Reg or EC. Also, if you use a SIPHON tank, then there is NO NEED TO USE ONE. Regulators, and Expansion Chambers were designed to solve the problems associated with using REGULAR co2 tanks.

However, some people use Zs in VERY HOT weather. In hot weather, SIPHON tanks are useless, since all the liquid in the bottle turns into vapor about 90 degrees (and velocity drops). In such a situation, the VALVE in the Z can be switched from the LIQUID valve (WINTER or SUMMER) to the GAS valve. Also, a regular CO2 tank must be used.

Such the case, the Z would work like a normal paintball gun, and suffer from all the problems that a normal paintball gun suffers from (as mentioned above). SO, to remedy these, one can get a REGULATOR, or Expansion Chamber to help ease these problems.

Can I use Nitrogen/HPA
Like a SIPHON tank, Nitrogen was designed to solve all the problems associated with co2 GAS. It does this very well. In fact, a gun that runs on NITRO would have all the benefits that a SIPHON tank has. Nitrogen doesn't have any real benefit over SIPHON. The only reason that many people are switching over to it is that most guns CAN NOT use a siphon tank. However, an average NITRO rig costs around $400, while SIPHON tank costs $60.

With all that aside, there is a couple reasons that you might end up using a NITRO system:

For those of you that satisfy one of these reason, Montneel Designs is working on a special NITROGEN valve for the Z. Its planned to be released in June '96.

Although any Z valve could be used with Nitrogen, the special NITRO-only valve is supposed to run very efficiently.

9. My Z

I have a 1 year old, SPLASH Mega-Z. With a hard-chromed BOA barrel, w/ rifling/muzzle. It also has chrome .45 grips. I run a 20oz SPLASH SIPHON tank on the vertical-bottle asa. It has a custom made stock. Plus, a VL2000 and a ADCO Square-Shooter on top.

10. Credits

Thanks to Brent Hoefling (aka Rambo Preacher) for the Anodizing, address and broken tank info. Brent_Hoefling@msn.com

Thanks to Ed Auyang for some more address info. Edward.Auyang@jhu.edu

Thanks to Tony for some construction criticism. (even if he has never used a Mega-Z).

Thanks to Nathan Fisher for some more constructive criticism. (even if he is Vector biased). Fishern3485@cobra.uni.edu

Thanks to Mark Rosenkrantz most of all. If it wasn't for Mark, I probably would of gave up on the faq. (especially when I got flamed for the first one). Probably 1/3 of the info in this FAQ came from him, including info on the various Z models, the upgrade history, the nitrogen information, the Z-rental information, the MZ-16 info, the valve info, the complicated SIPHON info, and the boa info. - Marker510@aol.com

Geeez, you would think that none of the info came from me!!

11. Sig

JINXED! Master of the Pan Flute!!

jinxed@corin.com

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