68 Special Owners Manual

The Model 68-Special Operator's Manual

Sorry for the scan quality. I will post cleaner copies when I figure out the editor. If an image shows blank then try reloading this page. There are a few .pdf copies available on the web if you search. I am reluctant to link at this time due to issues I have with some of the other data posted on the sites. Maybe after I finished my blog and calmed down.

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I am currently gathering together relevant CO2 technical documents to show the actual physics involved with this marker. The actual formula calculations will not be possible due to environmental and marker variables, but the concepts can be clarified. As of now I have not found a single web site that doesn't use "Dry CO2" data when referring to the operation of the 68 Special. I have even found a few that make me say WTF?  It's obvious they have only used HPA electronic markers. 

        I don't like to be a cynic but we'll see how popular HPA becomes when atrophy begins showing itself on aging HPA systems. Considering that an old tire over inflated to 70 psi can kill you. Imagine the fun to be had with 3 to 4.5 thousand psi. Darwin awards are in the works for the ones that say " Get the compressor, Let's see if it still works!"

Ok, I vented, I feel much better now....

                                                                                                                                                         SML
Blogger.com user StrayBlackCatsMeow

Address http://68-special.blogspot.com/
Blog "The 68-Special from Tippmann Pneumatics Inc"
Blog Reference page number 05
Title - The Model 68-Special Operator's Manual
Revised - 08/22/13

TIL-SMGSPG

TECHNICAL INFORMATION LETTER - SMGSPG (121398)

Tippmann SMG Series, Bolt Main Springs

REVISION C - DESTROY ALL OTHER COPIES

OBSERVED PROBLEM: Pellet velocities other than stated for standard and high pressure bolt main springs. Varying velocities from similar main springs. Problem in identification of springs. Adjustment of gun velocities.

SOURCE OR CAUSE: Different steels, coil diameters, wire sizes, coil spacing, spring length, heat treatment and tensile strength,singly or in combination, will give different spring energies. The supplier's changing of a machine and/or machine operator between orders may also have an effect on each different lot of springs. A long spring may well be of a lower power than a short one.

In measuring the static energies of a particular set of springs in both standard and high pressure, we found that they varied from 2 1/2 to 3 pounds added energy in the standard, and 3 1/4 to 4 1/4 pounds in the high pressure. The averages were 2 3/4 pounds and 3 3/4 pounds. The maximum difference's between different lots of the same type were as much as thirty-five percent!

REPAIR OR PROBLEM REDUCTION: Simple measuring of the spring length or its superficial color will have no bearing on the spring energy as the factory can only specify an energy at a certain compression length to the supplier and take what they get. Springs normally cannot be identified by simple means.

The uncompressed length of the springs ranges from 180mm to 200mm. At the rest, or un-cocked bolt position, the spring is compressed to 137mm. In the armed, or cocked bolt position the spring is further compressed 50mm more to 87mm. The difference in measurement is not kinetic energy. When the bolt hits the gun valve body, it has gained a lot more force. It is however, sufficient for our purposes.

To measure yours, obtain a simple kitchen or mail scale which has a range of ten pounds or more. Slide the spring over a 1/8" rod of nine inches or more in length. If possible, thread a 6X32 nut on the end to keep the spring from forcing off the end and then bending upon release. Slide a 1/8" washer over the rod on top of the spring the a larger washer or spacer to gain grip. Place the nut end of the rod in the center of the scale top and with a metric ruler, compress the spring to 137mm. Read the weight from the scale. Continue compressing to 87mm and read the scale weight again. Subtract the 137mm reading from the 87mm reading. This is the static or added energy of the spring.

The above is all academic though. All guns are different. The prime rule in both internal and external ballistics is, "You can engineer the hell out of a weapons system, but you never know what it will do until after you pull the trigger." The moral is simple. Clean your gun, lube it, then take it out to your field's chronograph. That is the only way you will know what velocity that spring will give in that gun.

Before chronographing, wait until after the temperature of the gun, CO2 cylinder and paint have stabilized. Normalize your gas system with three shots pointed up in the air, and then shoot three round sequences holding the barrel level without pointing it down until done.Keep the muzzle well to the rear of the light cell to prevent falsing. Keep in mind that changes in the ambient temperature, and hence the CO2 pressure will vary velocities considerably. Guns equipped with an All Weather Tank will record higher velocities with the same spring. You should make a set of springs cut to different lengths.

To adjust spring energies, cut off several coils at a time and retest. Use nippers, not your side cutters if you value them. Do not attempt to increase the tension by stretching the spring. You will be torquing the wire coils beyond design specs and weakening them.  The length will recede in time and the spring will have less energy than it started with. If you want more tension, order one or more high pressure springs and chronograph them to get the tension you desire. USE ONLY FACTORY SPRINGS! Spring design is very intricate. One that, "looks about right", may eventually damage the gun valve internals, receiver, or end cap threads. Cutting more than 10% of  spring length may give erratic velocities. High pressure springs cannot be cut down far enough to equal a low pressure one.

To verify one claim that adding spring coils to a regular spring increased velocity, we conducted our own experiments. We found that very little extra spring can be added as there is only a small amount of available room. The additional spring coils crowding into this space resulted in a binding and over-compression of the springs, AND A NET LOSS OF ENERGY OF APPROXIMATELY 10%! Therefore, only a spring DESIGNED with a certain amount of energy, at a certain compression will work in the SMG Series of guns.

RELATED INFORMATION: All SMG-68's were equipped with the standard 2.5 lb. spring until late 1988. All are now equipped with the 4.0 lb. high pressure spring. Some guns sneaked thru with 5.0 lb. winter springs. These yield 400 fps in summer and are dangerous. SMG-68's and Special's normally only use a standard pressure spring. Springs must be kept very clean and well lubed, as they will wear from friction and lose energy over a period of time. See also TIL-GENVEL, TIL-SPCVEA, TIL-SMGCLN and TIL-SMGOIL.

This document is retyped from a low quality copy that was hard to read. I don't type but the information is so important that it had to be done. Note that because the 68s are liquid fed, seasonal spring changes are not needed.                                                            SML


Blogger.com user StrayBlackCatsMeow

Address http://68-special.blogspot.com/
Blog "The 68-Special from Tippmann Pneumatics Inc"
Blog Reference page number 04
Title - TIL-SMGSPG
Revised - 10/18/14

TIL-GENORID

INSTRUCTION SHEET - GENORID (030891)

Tippman O-Ring Identification and Use

REVISION B - DESTROY ALL OTHER COPIES

DISCUSSION: User trouble in identifying o-rings purchased in kits for Tippmanns Pneumatic's paintball guns, and in determining when to replace them or where to use them. See also TIL-SMGSEAL AND TIL-SMGOIL. Pneumatic Ordnance o-ring kits are total kits, comprising ALL the o-rings in the guns concerned. Certain kits have extra tank valve o-rings. Some o-rings are used less often than other's or only in specific situations. All are also sold separately or in packages of two.

     One o-ring can have different uses in the same gun and unrelated uses in other models. It is therefore difficult to name them separately. They are identified by size, and are measured by their internal diameter and cross section thickness. The outer diameter is rarely used but is given here for ease of identification. The color, material, particular gun, service and probable usage rate are also listed for consumer information.

     Whenever an o-ring is suspect, replace it without hesitation. Never attempt to salvage one, or try to determine if it is usable by eye or touch. These methods are unreliable and problem prone. Junk it for the slightest reason. Noeprene o-rings should not be used in conjunction with petroleum based oils or in high pressure conditions unless well restrained. Urethane tolerates oils and high pressure better but may  be more expensive. Buna resists chemical attack very well, and is more cost effective than urethane. Teflon should not be used in sliding applications. Viton strikes a balance between rough service, attack and absorption. Liquid operation and using siphon cylinders may cause gas and gun valve seals to erode and leak sooner.

7/8" x 1" x 1/16" - Black Buna (Milky urethane from factory)
   SMG60 1st Gen, SMG60 2nd Gen, SMG-68 and 68 Special - Used as main or rear bolt seal, and as gun valve ring seal. Low pressure and only under fire. High movement on bolt, moderate movement on gun valve ring, dirty environment. Moderate usage, replace at the beginning of season and more often if regular use or in dusty conditions. Set of two.

3/4" x 15/16" x 3/32" - Black Buna
   68 Special Only - Used as power tube face seal. Low pressure and under fire. No movement, clean environment. Zero to low usage, replace only if lost or damaged. One o-ring.

5/8" x 3/4" x 1/16" - Black Buna
   SMG60 1st Gen Only - Used as gun valve body seal. High and constant pressure. Moderate movement, clean environment. Moderate usage, replace at beginning of season, when in heavy use or whenever the gun valve is removed. Set of two.

9/16" x 11/16" x 1/16" White Teflon (Milky urethane from factory)
   SMG60 1st Gen, SMG60 2nd Gen, SMG68, 68 Special and SL68 - Used as cylinder pin valve seal. High and constant pressure. Low movement but dirty environment and rough service. High usage if not kept clean and greased, or if cylinder is not inserted vertically. Clean, inspect and re-grease whenever cylinder is refilled. Replace instantly if the slightest imperfection is seen. Do not use black neoprene or buna. One o-ring, spares recommended.

9/16" x 11/16" x 1/16" - Black Buna
   68 Special - Used as front bolt breech seal. Low pressure and only under fire. Moderate movement, dirty environment. Moderate usage, replace each season, more often if in regular use or in dusty conditions. One o-ring.
   SL68 II - Used as receiver end cap seal. High and constant pressure. Low movement, but dirty environment and rough service. High usage if not kept clean and greased. One o-ring, spares recommended.
1/2" x 11/16" x 3/32" - Black Buna (Milky Urethane from factory)
   SL68 Only - Used as bolt breech seal. Low pressure area and only when under fire. Moderate movement, dirty environment. Low usage, replace each season or if no compression is felt on closing bolt. One o-ring.

7/16" x 5/8" x 3/32" - Brown Viton (black neoprene or buna from factory)
   CAM Constant Air Magnum Steel 4.5 and 9 Ounce CO2 Cylinders - Used for pin valve end seal. High and constant pressure. No movement, but dirty environment and rough service. High usage if not glued in with gasket cement. Buna or urethane o-rings will pop out easily from CO2 absorption and expansion on depressurization. Replace as necessary from loss or damage. Do not peen in, keep greased. One o-ring.

3/8" x 1/2" x 1/16" - Black Buna (Milky Urethane from factory for SL68 only)
   SMG60 1st Gen, SMG60 2nd Gen, SMG68 and 68 Special - Used for gun valve plunger cup seals (gun valve plunger collars or seats). High and constant pressure area. no movement, clean environment. Low usage, replace if gun valve is disassembled or leaking. Easily damaged on removal of plunger. Do not mistake for plunger seal leakage. Set of two.
   SL68 - Used for gas valve body seal. High and constant pressure area. Low movement, clean environment. Low usage on SL II, high on 1st gen. SL. Easily damaged on 1st gen SL68 valve removal. Do not mistake for valve seal leakage. One o-ring on 1st gen., two on SL68 II.

5/16" x 7/16" x 1/16" - Black Buna
   68 Special Only - Used for retaining bolt link to bolt handle and front bolt arm. No pressure. Low usage, replace as necessary or if visibly damaged or worn. Set of two.

3/16" x 5/16" x 1/16" - Black Buna
   SMG 1st Gen - Used for gas line elbow and gun valve screw (rear sight) seals. High and constant pressure. No movement, dirty environment. Low usage, replace if damaged or slow leaks develop. Set of three.
   SMG60 2nd Gen, SMG68 and 68 Special - Used as packing for rear gas tube ferrule compression screw protrusion adjustment. High and constant pressure. No movement, clean environment. Zero to low usage, replace equal number when gas tube is replaced, add or remove as necessary to change protrusion of screw. One to three may be needed.
   Tippmann Pneumatic's 3.5, 7 and 20 Ounce CO2 Cylinders - Used as pin valve rupture disk seal. High and constant pressure. No movement. clean environment. Low usage, replace whenever rupture disk is replaced. One o-ring.

5/32" x 7/32" x 1/32" - Black Buna
   SMG60 1st Gen Only - Used for gas line screw seals. High and constant pressure. No movement, clean environment. Low usage, not available except when purchasing the entire gas line assembly. Use 3/16" x 1/4" x 1/32" o-rings with slight bevel on the edge of the screw hole, or automotive form-a-gasket compounds.


This document is retyped from a low quality copy that was hard to read. I don't type but the information is so important that it had to be done.                                                             SML


Blogger.com user StrayBlackCatsMeow

Address http://68-special.blogspot.com/
Blog "The 68-Special from Tippmann Pneumatics Inc"
Blog Reference page number 03
Title - TIL-GENORID
Revised - 08/22/13

68 Special: Out of the box Specifications

Tippmann Pneumatics 68 SPECIAL

Top half are the accessories that were available at the time: Stock Tippmann 20oz Siphon tank with generic buttstock, 100 Rnd Viewloader hopper (the biggest the store had but its expandable), Stock Tippmann Sniper Barrel, generic hopper adapter (painted pipe fitting). Shown in the lower half of the box is what you got. Owners manual, patch, spare O-rings, The 68 SPECIAL, 40 Rnd hopper, 7oz siphon tank, squeegee, sling and filler adapter with rubber washer. The marker with no accessories was purchased new in 1991 for $369.00+tax. This was their display marker, the 68 Specials were back-ordered with no scheduled delivery date. I can't remember what the accessories cost, they were purchased later. In those days stock Tippmann parts were expensive.
I have seen a number of recent 68 Special sales, all claiming to be in excellent condition, complete and original straight from the box. Most were actually in poor condition and damaged with ill fitted mods, as well as having non-Tippmann or missing original parts. I am posting this to show what really came in the box. Sorry, It's NOT FOR SALE, so please don't ask.

This is from the manual. Compare this to the ridiculous number of parts in modern markers. The earliest 68-Special design is shown on this diagram. Receiver tube is SMG-60 without the safety, the receiver is not yet milled for the valve retainer spacer which is not shown. Valve has not been milled for the valve retainer spacer.  Trigger is SMG-60 Gen2. Power tube is of first run design.. There is a roll pin under valve from SMG-60 Gen2 on this model. I have rendered from this diagram an accurate exploded view and parts list of the last model that I will upload at a later date.

Specifications of the Tippmann 68 SPECIAL

Caliber:........................................................................................................68
Power:.................................................................CO2 (7 oz. siphon cylinder)
Mag. Capacity...........................................................................................50+
CO2 Capacity..............................................................225 shots per cylinder
Cycle Rate:......................................................................................300 RPM
Standard Barrel Length.............................................................................11"
Length-Overall:..........................................................................................32"
Weight:....................................................................................................4.8 lb.
Effective Range:..................................................................................150+ ft.
Action:..........................................................Semi-auto (open bolt blow-back)
Tippmann Stock SNIPER Barrel Length...................................................16"

One thing to consider along with the roundness quality when selecting paint is the paint ball diameter size and size consistency. The 68 cal paintballs vary in size depending on the manufacturers or brands. They can range from .684" to .694". Modern paintball markers favor the smaller size. These can result in lower velocities, poor accuracy, and breakage issues in the 68 Special. The optimum size for consistent velocity and accuracy is .692". Charts are available on the net to check the nominal sizes of the brands your field carries for the best selection.

Due to the nature of the liquid CO2 "Wet System" , After the tank is installed and before paintballs are added at the chronograph station. The marker should be pointed upward and rapidly fired three to four times to "wet the system" (remove all gas from the lines and valve). This puts the marker at its maximum velocity for chronograph purposes. [Note that doing this with a dry CO2 marker will temporarily lower the velocity, a primary difference in the two systems.] Most likely your field will not be familiar with wet systems and rather than argue the fact chronograph the first seven shots, the last three being your velocity. Been there. done that.
     To save on tank seals when removing a still charged tank. Unscrew the tank 3/4 turn, invert marker to dump balls from feedneck back to hopper and fire marker in a safe direction. It will fire three to four times with remaining CO2 in the receiver  The bolt will remain closed when empty. The tank can then be removed without the hiss and O-ring damage. Lube the o-ring for longer life.

I am posting on this site the only two Technical Information Letters from Tippmann that I have found so far, TIL-SMGSPG and TIL-GENORID. These Refer to all early Tippmann markers but contain extremely useful information on the 68 Special's main spring and O-rings. I wish I had these when I bought my marker, I probably didn't need to replace the valve seats, only the o-rings. If anyone is aware of the location of the following TILs, Please direct me to them in comments so I can get and post them. The needed TILs are:
TIL-GENVEL

TIL-SMGCLN
TIL-SMGOIL
TIL-SMGSEAL

TIL-SPCVEA   < This one is of great interest as it may supply extremely useful information on the 68 Specials velocity adjustment system.The others may have useful references.

I copied my owners manual and will soon be posting it after I crop and size the scans.


                                                                                                                                         SML


Blogger.com user StrayBlackCatsMeow

Address http://68-special.blogspot.com/
Blog "The 68-Special from Tippmann Pneumatics Inc"
Blog Reference page number 03
Title - 68 Special: Out of the box Specifications
Revised - 08/22/13