VM Cycling/Cold Weather MINI-FAQ v2.3

• A. The valve both directs pressure to the bolt to fire the paintball, plus, recocks the hammer. When the valve is at 12, velocity is highest, but, pressure to the hammer is lowest. Often lowering the clock will help VM cycling (though, will also lower velocity, but turning in the BOLT screw can help maintain adequate velocity levels).
• B. Drill the Valve out. There are 2 methods to drilling a valve: 1- First, to raise velocity, one of the clock holes can be drilled larger, to allow for more co2 to go to the bolt (though decreases cycling performance). 2- Second, to improve cycling, the recocking jet can be drilled larger to allow more co2 to recock the VM. Either MOD is bad for CO2 performance, but is a good LAST-RESORT for improving cold-weather performance. Have a professional modify the valve (or see the homebrew section).
• C. Clean the Valve. It is possible that the valve might have alot of 'gunk' in it. (perhaps you tried to use lithium grease). Just pull the valve out, clean it, and replace it. (note the time on the valve).
• D. Valve Spring. VM/PMI3s all basically have the same VALVE SPRING. If the spring was CUT, or a lighter one was used, then the velocity would increase and cycling would improve. For a cheap fix, you can remove the Valve Spring. This works unless you have a bad cup-seal, in which the cup-seal will not seat properly without a spring. So, avoid removing the valve spring, unless its an emergency.
• E. Cup-Seal. When a Cup-Seal goes on a VM, it goes in STYLE. Cup-Seals are either the 'old' kind or the 'new' kind. Most PMI3s using the 'old' kind can upgrade to the 'new' kind. The new kind is supposed to be more durable, though, being shorter, its rather tricky to put in. While not directly related to velocity, bad ones leak, and can really make for a bad day. Usually running lubricant through the c/a system is a good temporary fix, until replacement is possible.
• F. Valve Screws. When the hammer hits the valve, a specific amount of co2 is released. Alot of PMI3s, mostly old ones, loose ALOT of CO2 out the Valve screws holes. By simply putting alot of Teflon® tape on the Valve Screws, or using a small o-ring around the screw you help the VM cycling ALOT. Plus, it helps keeping all the lube from coming out the side onto your hands.....

• A. O-RINGS. The upper bolt has 4 rubber o-rings. Some times they get worn, BLOATED, or are the wrong size (replacements) . If this happens, make sure they are replaced (with the right size). Make sure to also check the o-ring on the lower bolt (hammer), and the o-rings on the valve (which should never go bad). Aftermarket O-ring kits can IMPROVE cycling alot.
• B. Air Flow. 2-E of All Americans, told me that VMs that have hoses (ie bottom lines, remotes, etc), sometimes get clogged with lubricant. Sometimes the problem is that liquid runs through the hoses and gets the lubes so cold that it makes the lube so thick that it slows/stops the air flow into the valve. He said that best thing was to run sesame seed oil through the HOSE. (2-E of AA said this). Plus, running a solvent though the gas line will dissolve the lubricant (and hopefully not the o-rings).
• C. Liquid. VMs were designed to run straight vapor. But are capable of running liquid (siphon tanks) to gain all the advantages of using liquid. The important advantage being velocity, and pressure gain. VMs with cycling problem can usually be fixed (at least temporarily) by putting on a SIPHON tank. Note, excess liquid in a VM can also make the o-rings on the upper-bolt expand (so I am told). Also older PMI3s have cheaper CUP-SEALS that will leak when using a siphon bottle, though, replacements are VERY cheap. NOTE: The VM-EXC cannot make use of a SIPHON tank, becuase it has a EXPANSION CHAMBER, or any VM with an expansion chamber or regulator.
• D. Expansion Chambers and Regulators (with CO2). Some people tell me these help VMs in cold weather, while others have told me different. They DO lower the operating pressure, and I believe they do not help the VM COLD weather (and usually makes VM cycling worse).
• E. Nitrogen. The great thing about NITROGEN is that its a GREAT improvement over CO2. If the VM has a cycling problem while running NITRO, then just TURN UP THE PRESSURE! Presto! Plus, NITROGEN is NOT effected by TEMPERATURE/WEATHER like co2.
• F. Delrin bolts. I have heard that alot of people have problems with the frictionless, and o-ringless Delrin Bolts. The problem is 2-FOLD. First, I heard that Delrin bolts SWELL when they get cold, especially when the come in contact with LIQUID Co2, creating friction in the VMs cycle. I have had a delrin bolt in my VM for many years and never had problem like this. Second, since the delrin bolts have no o-rings, the OD of the bolt has to match the ID of the barrel. In theory this works fine, but its possible that if you pinch a ball, you could get a piece of shell between the bolt and breech, jamming the gun. This has happened to me in a tournament, and the VM jammed so bad, that I needed to use a hammer to get the bolt unstuck!!
• G. COLD WEATHER. Most of the VM cycling problems are encountered in cold weather. This is do to the bottle pressure being lower (with far fewer useable shots), and LUBRICANT thickening. ALot of people tell me (like SP), that the VM is a warm weather gun, not to be used in cold weather. I tell them "GARBAGE!". The VM can function in cold weather just as well as an ICON Z1/2 or a PRO-AM/LITE (especially with a siphon). Most of you are probably saying, "But, my VM doesn't function in cold weather??". Well, if you go through my ENTIRE MIMI-FAQ, to make sure your VM is running MINT, then it should work well below 0 degrees. Even without a SIPHON or NITROGEN. I live in MAINE, and Doug lives in Michigan -we know COLD Weather. In January, I put away the 'cocker, and use the VM as a WINTER GUN! Running SIPHON or NITROGEN WILL greatly improve the winter performance.
• G. New VMs. I have seen alot of COMPLETELY NEW Vms, straight from TASO-EAST, that go CYCLIC (full-auto) for NO APPARENT reason. I told my friends to RETURN their guns, which they did. The new ones they received worked fine. I suspect that since SHERIDEN is UNDER Crossman CORP now, the Quality Control is NOT-AS-GOOD as it used to be. I understand that they are selling them for ~$180 now, but that no reason for them to sell low-quality products. The people from TASO East felt the same way, they dont want to loose customers because Crossman is cutting corners.

--Prices, and availability are subject to change.

VM-68 PARTS AND PRICE LIST
REF NO. PART NO.        PART NAME                       PRICE
1       VMX-A01         RECEIVER ASSEMBLY               $184.40
2       VMX-111         AIR CHAMBER ASSEMBLY            $ 12.70
3       VMX-121         EXHAUST VALVE ASSEMBLY          $  6.25
4       VMX-200         BARREL ASSEMBLY                 $  8.50
5       VMX-241A        UPPER BOLT ASSEMBLY             $ 12.00
6       VMX-251A        LOWER BOLT ASSEMBLY             $ 38.00
7       VMX-9011        TRIGGER ASSEMBLY                $ 51.80
8       F503            AIR VALVE SPRING                $  0.50
9       VMS-003         BARREL RETAINING NUT            $  6.50
10      VMS-102         SCREW                           $  0.85
11      VMS-103         LOCKWASHER                      $  0.25
12      VMS-201A        BOLT CONNECTING PIN             $  3.50
13      VMS-231         UPPER BOLT O-RING               $  1.35
14      VMS-252         LOWER BOLT O-RING               $  1.10
15      VMS-257A        SAFETY SLEEVE                   $  1.80
16      VMS-258         SAFETY FASTNER                  $  0.25
17      VMS-403         LOWER BOLT PLUG                 $  8.00
18      VMS-404         UPPER BOLT PLUG                 $  5.30
19      VMS-405         PLUG RETAINING BOLT             $  0.45
20      VMS-406         LOCKWASHER                      $  0.25
21      VMS-502         SCREW                           $  0.40
22      VMS-503         SCREW                           $  0.65
23      VMS-510         PISTOL GRIP                     $ 11.50
24      VMS-520         SCREW                           $  0.35
25      VMS-601         BALL FEED ADAPTOR               $ 28.50
26      VMS-603         BALL RETAINER                   $  0.90
27      VMS-604         BALL FEED SPACER                $  0.85
28      VMS-605         BALL FEED FINGER PLATE          $  1.85
29      VMS-606         SCREW                           $  0.35
30      VMS-610         BALL FEED FASTENER              $  2.50
31      VMS-700         MAIN SPRING                     $  3.15
32      VMS-701         MAIN SPRING GUIDE               $  0.40
33      VMS-800         MONO POD                        $ 11.50
34      P911            BALL INSERT TUBE - 45           $  4.70
35      VMS-5010        GRIP LUG                        $ 11.85
36      PT-418          VEL. BOLT DETENT BALL           $ 11.85
37      P700            FRONT SIGHT                     $  0.85
38      CH4             O-RING                          $  2.50
39      VMT-T01         VELOCITY ADJ. TOOL              $  6.90

I will just say this once. The stock VM barrel is garbage (except the Magnum barrel). The finish is always poor, and brass barrels get scratched VERY easily. Plus, the ID is .690 which is way to tight for big bore paint (ie Nelson, Bullseye). However, the STOCK barrel can be easily modified to shoot good. All it really needs is to be bored to .692 and honed/polished. A good honing kit will do both. An airsmith can also hone the barrel for you, but it might actually cost less to simply buy a new one.

Almost ANY aftermarket barrel is a great replacement, which should yield better range then any 'mag. Part of the reason for the poor range and accuracy is the inherent turbulent nature of a blow back semi. When the 68-special, Golden Eagle (chuckle), and PMI3 first came out many years ago, many pro players stayed with their bushmaster pumps, due to the poor accuracy of the smooth-bore semis. When RIFLED barrels came out, this changed everything.

Expansion chambers allow the co2 to pre-expand before being used, thus more efficient. There is a number of different types, some do very little while others are very helpful. The most common is the original Black-Rain system (by AirAmerica), which can be setup in a BACK_BOTTLE (Terrorist), or BOTTOM-LINE setup. This is the best chamber, and most expensive at $100-$160. If you already have a DUAL-BOTTLE setup, and a 3oz (ie MAGNUM), COOPER-T makes a special valve, that fits on the 3oz, that turns it into an expansion chamber. I hear this works well. Taso makes many different styles of CHAMBERS ranging from small ($20) to large ($100), all are quality devices. Avoid cheap small chambers, they're not worth the money. Also, a remote system also works as a partial expansion chamber. SmartParts makes an REMOTE/EXPANSION CHAMBER for about ~100. The Chamber (designed by AIR- AMERICA) fits on the bottle, and also features a quick-disconnect, allowing it to switch from gun to gun (great deal). Taso, and I&I also sell similar setups.

Two common aftermarket VAVLES are the MAGNA-PORT valve, and the PRO-VALVES. The MAGNA-PORT valve reduces the number of CLOCKS to one, plus features VENTURI recocking jets. Its advertised to raise velocity, efficiency, cycle rate, and cold weather performance. Pro-valves are similar to the MAGNA-port valves (with one clock), plus feature delrin cup-seals which last longer then the stock cup-seal. I would suggest that you avoid aftermarket valves. It is true that the raise velocity, and cold-weather performance, but they SEVERELY hurt co2 efficiency (more so when using Expansion chambers). Your efficiency could drop up to 60% with the custom valves. They are ONLY useful in SEVERE cold weather, without an expansion chamber. Plus, I have heard people say that they have a hard time installing them, especially in VMX's.

The STOCK hammer on the VM is FINE for the most part. However, aftermarket Hammers can add some special features. Some hammers are made from aluminum, or are drilled for lightness. Light hammers cycle faster, providing for a greater rate-of-fire. Other hammers are designed to allow for velocity adjustment from the back of the VM. Probably the standard replacement hammer for the VM is the PHAZZE II. Both TASO, ABC, I&I, PRO_COMP, and COOPER-T also make quality aftermarket hammers ranging from $50-120.

VM HOME-BREW

If you're like me, you think you can save money by doing custom work yourself (and you probably don't read the manual for anything either). Alot of the CUSTOM work below was summarized because the full length description took up too much space. If you email me, I'll me happy to explain the idea's more fully.