Weihrauch HW100 PCP Air Rifles have an established a presence in Australia with the HW100T and the HW100S, both as leading PCPs* 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 in numbers for reasons that evade me. These are the carbine versions of the HW100T and the HW100S, currently designated HW100TK (KT) and HW100SK. The Weihrauch HW100 also has an FSB model, which stands for Fully Shrouded Barrel. 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 we sell. Both the Weihrauch 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 Match or H&N Baracuda Hunter.
The .177 HW100 is an accurate combination out to 50 metres in its factory form and after that distance the pellets tend to lose 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 sometimes 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. I am also “Mapping” the Weihrauch HW100 PCPs to find the ‘sweet spot’ of the regulator output: which varies with each gun.
Presently the HW100T comes with an ambidextrous wood thumbhole stock together with a laminate and synthetic versions that step this air rifle up in popularity. There are other things in the wind at Weihrauch, but being in Australia we are at the bottom of the food chain so don’t expect anything to happen too quickly (the date editing this is mid-July 2018). Edit: Both laminated and Synthetic are available here at present. The laminated model is designated SE for Special Edition. Date 2/7/18. Ian Mc.
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.
The stock however, is extremely well finished and a compliment to the manufacturers, making the Weihrauch 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.
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) in your Scope Ring Set and bin it.
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…..stupid is forever.
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 Weihrauch HW100 Charging System.
The HW100 PCPs come with 2 magazines that hold 14 shots each and with the standard air chamber will deliver around 35-45 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 negligible effect. However, many of you reading this use a Weihrauch 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.
- Get the charging port and hammer spring customized as mentioned earlier in this article.
- Get the Regulator ‘Mapped’ to increase the efficiency, power or shot count.
I will provide a graph and shot count verses pressure in a coming article on the Weihrauch HW100 where Joe Tonga and I field tested 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 Weihrauch.
Weihrauch HW100 Summary.
This article is but 1 of several planned, as the Weihrauch HW100 will take more than just a few articles before you for truly understand the complexities and characteristics of this PCP air rifle. 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 truly their equal.
Ian McIntosh 18/04/2018