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Weihrauch Air Rifle Tuning Basics

Being a WeihrauchWeihrauch air rifle stockist and a keen owner of some of their air rifles, I have taken to air rifle tuning of Weihrauchs only. Specifically I do not have the time to source parts for other brands and to learn the different idiosyncrasies of different air rifles. There is still plenty to learn about Weihrauch air rifles.

Weihrauch HW97K air rifle

Weihrauch HW97K

I am fielding calls about our database of pellet and Weihrauch functionality and comparisons almost daily, so in this article I hope to answer some of your questions.

Air Rifle Tuning Pre-Checks.

Before you go ahead and decide that your air rifle needs tuning, you need to establish that you have done and are currently doing everything correctly. If not, then no amount of tuning is going to provide better results for you and you will have wasted your money.

Air Rifle Pellet Selection.

Firstly, look at your pellet selection and pick a pellet that you feel gives you the best results. If you are using budget priced pellets then it maybe pertinent to invest in a higher quality pellet and track any improvement in your grouping.

H&N Baracuda Hunter Pellet

Baracuda Hunter

Such a pellet should be something like the H&N Baracuda, H&H Baracuda Hunter or the JSB Exact Jumbo Heavy pellets. There are also undoubtedly other high quality pellets that will provide consistent accurate grouping.

Parallax Errors.

The next thing I would be looking at is whether you are experiencing any parallax error through your scope. For those of you new to this, parallax error is when you view your target through the scope and the reticle ‘moves’ side to side on and off the target when you move your head side to side. In fact, what should happen is that the reticle should remain steady on the target even when you move your head side to side.

Hawke Scope 3-9 x 50 AO

Hawke Scope with Adjustable Objective (AO)

Causes of this are usually due to the setup of your scope being incorrect. Short story is to get your eye relief sorted so you are in a comfortable position with your scope and then adjust the eyepiece so you are fully focused on the reticle with no blurring.

Then adjust your Adjustable Objective (AO) to give you the best focus of your target and this will eliminate any parallax error most of the time. Should you have a scope with a fixed objective and you still have some parallax error creeping in, then please contact me and we can work through it together. I will do an article on parallax error down the track a bit – just remind me.

There is one thing that needs pointing out here and that is the distances stamped on the Adjustable Objective. These are a guide only and help in range finding, however, should you be shooting at 20 metres, don’t expect the AO to be exactly on 20 metres. It will be close but not necessarily exactly right on the money. So if you are experiencing some parallax error adjust for clarity and focus rather than using the setting on the AO.

Posture.

Quite often a guy will come to me saying that he can’t hit poop with his air rifle because it shoots like crap – no pun intended, just trying to be polite here. When asked to demonstrate this for me I have noticed on occasions that the shooter has to crane his neck at an awkward angle, lean forward or backward with his head and then crouch over the gun. He ends up looking like the hunchback of Notre Dame. No wonder he can’t hit anything and no amount of tuning is going to help him.

It is extremely important that the scope height and eye to scope distance is set up correctly for you; so that by just swinging the air rifle up to your shoulder is all that is required along with a slight head tilt. You need to get this part right so that muscle memory kicks in and you don’t need to re-establish your posture every time you want to shoot as this will save you “re-inventing the wheel.”

Trigger Pull.

As the reader you will know that I live in West Australia and here we have a firearms regulation that prohibits trigger pulls of less that 1kg unless you are shooting in a specific target shooting regime. That said, I reset the trigger pull of each air rifle I tune here down to 1kg though better results are often achievable with lighter trigger pulls of around 600 grams a lot of the time (I didn’t say that…).

This brings me to the point of setting your air rifle trigger pull into the realms of getting the right ‘feel’ and knowing just when it is going to shoot. I have had trigger pulls here of 3kgs and unless your name is Arnie, holding on target while squeezing the 3kg trigger is not going to be easy. So prior to deciding on whether your gun needs tuning make sure that your trigger pull is not causing your poor grouping.

If you don’t have a Trigger Pull Gauge you can get pretty close using a vertical lift off the trigger lifting a known weight. Go onto You Tube and search there and you will find several ways of calibrating your trigger pull. The Weihrauchs have the Rekord trigger which is very reliable and easily adjusted with a nice feel.

Extra Setback Trigger

Extra Setback Trigger Option

I can provide 3 different types of triggers for all the Weihrauch air rifles, from ‘Straight Triggers’ to ‘Extra Set-back Triggers’ in alloy, black anodised and brass along with 3rd party trigger guards.

Air rifle serviceability.

Prior to getting your Weihrauch air rifle tuned, make sure that the rifle is in fact in a serviceable condition as some of the problems I have experienced with customers air rifles are due to lack of servicing. If your air rifle is in generally poor condition then maybe a basic service/overhaul is all that is needed to bring it up to speed, after all, Weihrauchs are a solid and reliable air gun.

I say this because I recently had a guy bring in a Weihrauch air rifle for tuning and when looking it over I found several problems that were contributing to its poor performance such as trigger pull set too high, dust and crap in the trigger group, dry spring and a deteriorated barrel seal. After putting these right the air rifle shot very well and I was then able to set a benchmark by which I could compare the improvements made by fitting a kit.

Air Rifle Tuning.

So we are back full circle with regards to air rifleair rifle tuning. The bottom line is that if you are buying a new Weihrauch air rifle then I recommend that you get a kit fitted. Furthermore, if you let me know what you intend to use the air rifle for, I can specify one of several pellets and tune the rifle for that specific pellet as no air rifle tune covers all pellets.

With a V-Mach tuning kit fitted with the default shimming (Basic Tune) you will still have a formidable air rifle with a more controlled recoil and better accuracy. For those of you into hunting where you have to reach out further or if you are an avid target shooter, then a Stage 1 tuning kit will benefit your air rifle the best and help give you the grouping that you need.

Weihrauch Database.

In the past I used to do air rifle tuning by trial and error and by swapping out springs and cutting off coils etc., very primitive indeed even though I ended up with some good performances in the end. However, it is now 2014 and time is money and so I have taken it on myself to build a Weihrauch Air Rifle Tuning Database whereby I can fast forward and go into specific pellet and shim selection at a glance.

This has meant shooting 1,000s of pellets through both .177 and .22 Weihrauch HW97K, HW77k and HW77 models at distances of 10, 20, 25, 30, 40 and 50 metres all from a rail gun mount fixture. I have done this using my own rifles and those of several of my customers. Namely I wish to thank Mr. Mike Schifilliti of Adelaide and Mr. Kurt Carmichael of Townsville who allowed me to use their Weihrauch air rifles as comparison rifles in building the database which is still under construction. In doing this I have recorded the following into the database:

  1. Standard Deviation at the barrel and at the target using 2 Chronys.
  2. Highest velocities at the barrel and at the target.
  3. Lowest velocities at the barrel and at the target.
  4. Extreme Velocity Spreads at the barrel and at the target.
  5. Average velocities at the barrel and at the target.
  6. Pellet energies at the barrel and at the target.
  7. Groups.
  8. Decibels.
  9. Pellet speed decays.
  10. Pellet trajectories.
  11. Pellet to Pellet comparisons using 16 x .22 Pellet types and 20 x .177 Pellet types.
  12. Barrel Velocities over 1000s of pellets (spring conditioning, seal setting and bedding in)

When all the data has been entered into the database it will allow me to tune most Weihrauch air rifles more accurately and quickly and to a specific pellet.

Air Rifle Tuning summary.

While I would like to tune every Weihrauch air rifle I sell it is not always warranted and will say this to you: if you only want an air rifle to control vermin, do some casual target shooting or plinking, then the Weihrauch air rifle is plenty good enough.

However, if you are target shooting seriously or into hunting whereby you need to reach out more accurately and further, then do yourself a favour and get your Weihrauch air rifle fitted with a Tuning Kit that will reward you with better handling characteristics, smoother recoil, better grouping and ultimately better air rifle longevity.

Author: Ian McIntosh