Canadian Airgun Forum

The HW100 is a product of German engineering excellence and quality construction.
It design is well thought out. All major function groups are in modules, bolted together with quality grade 8 hex bolts. Very easy to service.
All parts are well made and of high quality material. All parts fit with precision with zero slop.



A - Sound Moderator: Used to reduce the report of the HW100. Held onto the 16", 16mm dia. barrel with bonding agent and a set screw. It is of decent performance, reports are kept to a bit above a HW95/R9.

B - Barrel Band: It is made of cast aluminum which has over-sized clearance holes for the barrel and air cylinder. At the mid-point of the holes are grooves for O-rings, which laterally restrains but allow free linear movements of the barrel and air cylinder. Also dampens barrel vibrations.

C - Action Block Front: The aluminum action block if made of two pieces, bolted together. The HW100 action would benefit from a rigid one piece scope mount. The action block front holds the barrel, breech, valve, regulator and air cylinder mount. Yes indeed, the HW100 is a regulated PCP. Only the front action block/barrel assembly needs to be changed to give you the various power versions of the HW100.

D - Action Block Back: The back portion of the block holds the pellet probe, magazine index and hammer mechanisms.

E - Trigger Block: It is made of a single piece of cast aluminum, with trigger guard. More sophisticated than Rekord and has more adjustments. Internal components are similar in quality to the Rekord. Performance is close to match quality. Excellent out of the box.

Excellent info, keep it comin' ..... any suggestion on mod ?

A - Sound Moderator, depending on country where purchased: Made of blued steel; 7/8" OD. and 6" in length. Front of moderator extends 4" beyond the muzzle. It has a single baffle at 1 1/4" from the muzzle. More descriptions of other parts to come.

Lets have a closer look at C - Action Block Front:

The front section of the action block is the 'motivation' part of the HW100. All the parts that contain and control the flow of the compressed air propellant are in this section. Two large grade 8 hex bolts hold the two parts of the action block together.





Part C1 is the part that directs the compress air to the pellet. It contains the breech, probe seal, porting and valve seat. Two hex bolt hold this part to the front action block C.



Part C2 is the valve assembly. A harden steel pin embedded into a Delrin or nylon valve. The valve body also served as a spring guide for a rather heavy valve spring. In front of the valve seat is a brass bushing (flow control device?). (*After some more work on the HW100, I notice that this brass bushing does help to keep the valve stem O-ring in place. With this bushing removed, the O-ring might come out of its groove and travel along the valve stem affecting velocity. I have since installed a trumpet shaped bushing which improved velocity slightly versus no brass bushing and, at the same time, kept the O-ring in place*)
The parts that control of the propellant in the HW100 is not much different then that in Crosman 22XXs or QBs.



Beneath the valve assembly is a pressure regulator. It is in-line with the inlet of the air cylinder. C3 is the regulator adjustment screw. The entrance of the barrel has an O-ring seal on its face to seal to part C1.
I was quit surprised at the amount of factory oil that is in this area.



A well thought out modular design. Easy to service and trouble shoot.

Would that C3 to regulate the power ?

Increasing the regulated pressure will also cause an increased force exerted on the valve. If the hammer do not have enough force to open up the valve, the power will go down. Power will go up with the increased pressure if the hammer force is strong enough to open it up. It is a balance.

So which means reducing the valve spring tension and increasing the hammer spring, it would do a good trick to increase power ?

The valve spring has very little effect on power.
I did a quick calculation. At 1500psi, there is more then 100lb force on the valve just from the air pressure. The valve spring contributes about 5 to 10lb at the most.
Increasing the hammer spring stiffness is more effective.

From your tech. analysis observation, what other parts beside the spring would you say that makes the different of 3 versions power of HW100 between the 35j, 16.3j and the 7.5j ?


THX

The HW100 is mainly designed for 16J.
To get the 7.5J version, a limiter is used to reduce the overall power the rifle can develope. To get the 35J version, a 7.5" longer barrel is added, the regulator is reworked, and internal springs are changed. This version is not very efficient as show on the specs., Only 30 shots. The air cylinder is a bit too small for this power level. You definitely do not want to pump up the air cylinder after every 30 shots. Unless you want a good workout.

true, would be a pain, pumping every 30 shots ....
every 140 or 420 shouldn't be too bad.

BTW: how many strokes of pumping to fill the tube ?
how about carrying a spare tube, is it possible ? or do you have to fill with the tube installed on the gun ?

THX for all the info's.

Sniper,
It takes about 80 strokes on the FX pump to fill the air cylinder from 90 to 180bar. Twice the number of pumps for my CZ200T air cylinder.
The HW100 air cylinder needs to be detached from the rifle to fill. Yes, you can get spare air cylinders.
There are after market air cylinders for the HW100 with QC at the front so one can fill it without removing it from the gun.

D - Action Block Back:

This portion of the action contain the pellet probe linkages, the magazine indexing and hammer mechanisms.




At a glance, the HW100 pellet probe D3 look similar to the one in the QB with a hollow center and a hole on the on the side. The side hole is directly above the port.
On closer examination, the HW100 probe is a lot slimmer and the probe tip have very thin wall and nicely chamfered; which should make it one of the most efficient probe designs.
The probe does not have a O-ring seal like many other air guns. The probe sealing O-ring is inside the breech instead.

The design of the hammer D4 is very ingenious. It goes through the center of the pellet magazine, which allow the HW100 to have a short distance between the axis of the barrel and the valve and yet still have the magazine tuck inside the action. Other guns without this design would either have the magazine protrude out like a growth and limit scope mounting options or have an inefficiently long port from the valve to the breech.
The the tip of the hammer is stepped to fix the amount of valve opening. One drawback of the hammer through the magazine is the small area of the hammer stop. Do not dry fire the HW100. Otherwise, without air pressure to slow down the hammer, it will easily peen the breech C1 where it makes contact.



Here is the action block back D, with the trigger assembly E removed. Two hex bolts hold the trigger assembly.
The end cap D1 covers the access to the mechanisms inside the action block back. It is held in place by two small hex bolts.



With the end cap removed and the cocking lever pulled back, you can see the shuttle D2. At the center of shuttle is a hammer tension adjustment screw.
The shuttle compressed the hammer spring on the forward stroke of the cocking lever, much like a QB. IMHO a much safer system than rear cocking and loading of the hammer spring.
Do not attempt to turn the adjustment screw inside the action or you will for sure damage something. The screw is locked in place with a small grub screw and some semi-permanent Locktite.
To make any adjustment, you must first remove the shuttle D2 from the action. This is done by taping out the cocking lever hinge pin with a punch.



Access to the hinge pin is limited. A slim straight and a curved punch is needed. Carefully Tap the pin out from the bottom just enough to remove the cocking lever.
The shuttle D2 can now be taken out. Remove the grub screw. Place the shuttle in a strong vice with aluminum jaws, use a long hex key to ease out the adjustment screw.



Clean off the Locktite on the adjustment screw. If you are keen, polish off the sharp edges of the shuttle and smooth out the hammer spring ends.
Reverse the procedure for reassembly.
To make a secure and yet easily adjustible screw, put a very thin smear of hot melt glue spot on the threads and replace. Leave the grub screw off.

ETA,

This is an excellent strip down and very well presented …… thankyou .

I have owned a 16J version for almost 12 months and can confirm that they are a first class airgun, however, over the past few months mine had developed a slow leak, where it would loose about 60bar a week !

Rather than package it back to the importer I decided to investigate and found the breech seal (O ring) to be leaking …… like you I was surprised at the amount of factory oil in this area.

As a point of interest, here in the UK we have the MkII version which has a threaded barrel and a very much quieter silencer ………. the importer was able to change the older type barrel (which you have) for the newer version on a one for one basis for a small fee .

I was interested in what you referred to as the brass flow control device fitted on the firing pin. Mine also has this and I thought it was to keep the firing pin central.

Regards



Bob

Welcome GPS Guru,

The hammer spring should not be adjusted too high or it will jam and refuse to cock and the trigger will not function . Back it out a bit so the cocking action is smooth. Because of the mechanical advantage of the cocking mechanism, cocking effort should still be very low and smooth.
If you take a look at the picture of part C1. The valve pin is well supported by an O-ring and the hole of part C1. I am thinking a cone shape bushing might smooth the air flow from the valve to the port for more efficiency with less expansion.
Even if you were to get enough air flow as a 35J version, you still have a 7.5" shorter barrel; therefore air is wasted and more noise is created instead of moving the pellet. Hope that helps.