Weihrauch HW100

The Weihrauch Range of PCP Air Rifles.

Weihrauch have an established a presence in Australia with the Weihrauch HW100T and the

HW100S, both as leading PCP* air rifles in their class. For those of you unfamiliar with

Weihrauch air rifles, the designation ‘T’ stands for Thumbhole stock while the ‘S’ stands for

Sporter stock. However, there are several other Weihrauch HW100 models that are not often

imported for reasons that evade me, and they are the carbine versions of the HW00T and the

HW100S, currently designated HW100TK and HW100SK. Weihrauch also has a FSB model,

which stands for Fully Shrouded Barrel and currently this is not allowed into Australia under the

misguided belief that the shroud qualifies as a form of silencer.

I will attempt to cover each model separately over several articles to allow you, the reader, to

get a more comprehensive understanding of the Weihrauch PCP range. * PCP, is an acronym

for Pre Charged Pneumatic, as it is powered by compressed air at 200 Bar, or nearly 3,000 psi.

The Weihrauch HW100T.

Statistically with me anyway, the HW100T in .22 calibre is the most popular HW100 series PCP

that Weihrauch make. Both the HW100T and HW100S come with 600mm barrels that I feel

are an improvement over their early barrels around 2005 and earlier. In my experience shooting

the Weihrauch HW100 PCPs, they are very accurate, with reasonable groups right out to 100

metres using a .22 calibre quality pellet like the H&N Baracuda or H&N Baracuda Hunter.

Weihrauch HW100T with Hawke Sidewinder Scope

Weihrauch HW100T

The .177 HW100 is an accurate combination out to 50 metres in its factory form and after that

distance the pellets tend to loose stability and develop an increasing spiral, thus affecting the

accuracy past this point. To overcome this problem you can do one of two things, or in fact

both if you like, and that is use a heavier pellet and/or wind back the hammer spring to reduce

the velocity a bit. Both work.

Firstly, let’s look at the heavier pellet option. This heavier pellet by virtue of its weight, co-

efficient of drag and cross sectional dynamics will drop like a stone over distance but will suffer

less from spiraling. The drop is no big deal as this is easily calculated and you can compensate

for it with hold-over using your Mil Dots – I will have an article on setting up your scope for

distance and using Mil Dots very shortly and this will include some custom targets so you can’t

get it wrong.

Now the hammer spring adjustment. This is a straightforward procedure that will require

dropping out the mechanism, undoing the guide plate and locking screw and then taking out the

hammer spring tension by up to 2 turns. This is not set in stone, so I would suggest 1 turn then

test the rifle and so on. What you will effectively do is reduce the pellet speed which in a

HW100 in .177 calibre is too fast with their rifling as it stands.

I will be working on the HW100 air rifle over the coming months as we are keen to develop a

tuning procedure for this PCP as the hammer spring adjustment only gives marginal controls. It

will give you extra shots per fill but once we develop a correct procedure for pressure

adjustment and hopefully a variable charging port (not manually variable) we will have the

ability to regulate the speed/power and give additional shots per cylinder charge.

Weihrauch HW100T


Presently the HW100T comes with an ambidextrous wood thumbhole stock in Australia though

I believe shortly we will be getting the laminate and synthetic versions that are available in

Europe at present. Being in Australia we are at the bottom of the food chain so don’t expect

anything to happen too quickly (the date writing this is mid February, 2015).

Personally I find the Weihrauch HW100 stock options kinda boring and this is one of the

reasons that influenced me into purchasing the Clone 4D stock duplicating machine. I will soon

be offering the Weihrauch HW100T and HW100S in custom woods or laminates directly from

this site.

The Weihrauch HW100S.

The HW100S is the Sporter version of the HW100 PCP range and is currently only available in

wood in Australia. This is not an ambidextrous stock unfortunately though anyone purchasing a

Weihrauch HW100S from me that is left handed, I can quite possibly make either a new stock

or modify the current stock. Note however, the cocking lever, even though it is only small, is on

the right hand side of the action which basically means releasing your hand to cock it.

Weihrauch HW100S air rifle

Weihrauch HW100S

The stock however, is extremely well finished and a compliment to the manufacturers, making

the HW100S more attractive than many other and more expensive PCP Sporters out there. The

action is a deep black with a high gloss finish and minimalistic appearance with minimal

projections such as loading bolt etc. Unfortunately, Australian Customs in their ‘wisdom’ have

regulated that the barrel weight not be fitted coming into the country as they deem it to be an

incomplete silencer, can you believe this crap? Hence these air rifles tend to look a little bare

so if you don’t like the looks then I can fit an Air Stripper for you or quite possibly an Air

Shredder if I can keep stocks up. Neither of these items will reduce the noise level.

Air Strippers for a HW100

Air Strippers for HW100

The Scope dovetail on these air rifles is 11mm and while it straddles the Rotary Magazine port,

you can still fit a one piece scope mount without interference. However guys, please note that

the HW100 does not have a locating dimple like the HW77 series does at the rear of the action

that prevents the scope from walking backwards due to recoil, so please unscrew the vertical

allen key (if fitted) and bin it.

HW100S with Sidewinder

HW100S with 3-12 x 50 Sidewinder

I have recently had a guy who did not notice that the rear mount vertical locating screw was

protruding slightly and he tightened up his scope ah la ‘Arnie’ style and put a bend in it…..

As the Weihrauch PCP air rifles do not have recoil as such, they do not need or employ the

locating dimple that stops the scope from walking backwards, so please check your mounts for

this locating screw or peg that is sometimes fitted.

The HW100 Charging System.

The HW100 PCPs come with 2 magazines that hold 14 shots each and with the standard air

chamber will deliver around 35 effective shots before you start to recognize speed decay.

When shooting at close range, say 30 metres, then you can quite easily get more shots from

each refill if you are shooting at targets as speed decay at close quarters has little effect.

However, many of you reading this use a HW100 for vermin control such as rabbits, and

therefore shoot out at longer ranges. You are likely to notice speed decay and pellet drop

earlier than those guys shooting close up at targets.

Unfortunately, Weihrauch have not made this rifle with a manually adjustable pressure

regulator and to me this is its main flaw. There are a number of ways to increase the shots per

air cylinder charge and they are:

  • Lower the speed/energy (by the hammer spring).
  • Use a larger cylinder such as the lightweight FX cylinders that we sell.
  • Get the charging port and hammer spring customized as mentioned earlier in this article.

The main issue is that the HW100 uses excessive air to propel the pellets and by customizing

the charging port so that this volume is reduced and the regulator pressure reset, more

consistent shots will follow as a result. Just got to work out how….

I will provide a graph an shot count verses pressure in a coming article on the Weihrauch

HW100 where Joe Tonga and I field test this air rifle out to 100 metres and provide you will

heaps of tables and graphs to assist you in both shooting and tuning your HW100.

HW100T and 100S Summary.

This article is but 1 of several planned as the HW100 will take more than just a few articles

before you for truly understand the complexities and characteristics of the HW100. I will also be

breaking down the components to give you comparisons between the HW100T, S, and the

carbine versions being the HW100TK and SK. This will give you the benefits of PCP air rifles

over springers such as the Weihrauch HW77K.

Over the next few months we will take testing to the next level prior to customizing the actions

in a bid to give you more shots and better accuracy, especially in the .177 calibre. The

Weihrauch HW100 is truly a great air rifle, very well built and priced below that of some of its

competitors with which it is their equal.

Author: Ian McIntosh