Weihrauch HW77K part 2

Part 2 of buying a Weihrauch HW77K Air Rifle.

I will continue here with the second part of this series of 4 articles on the Weihrauch HW77K

spring powered air rifle. In this article I will discuss the HW77K in .20 calibre and other features

that are common to the remaining 3 calibres.

The .20 calibre HW77K is not a common calibre imported into Australia due to the limited number

of competition air rifle target shooters. We have a fledgling competitive air rifle following at

present in Australia (at the time of writing this) and so the demand for the .20 calibre HW77K is


I carry the .20 calibre HW77K in Blue and Stainless in limited numbers as they were specially

ordered and had to be flown in from Germany after a protracted wait of many months.

The .20 calibre HW77K as a target air rifle.

This particular air gun makes a great target rifle due to the flat trajectory of the pellet’s flight path

and it being a slightly heavier pellet than the .177 making it pretty stable. It has a limited but vocal

following of air gunners who insist that the HW77K in .20 calibre makes a better and more

accurate shooting rifle than the very popular HW77K in .177 calibre.

Not being a user of the HW77K in .20 calibre I can’t really comment on this one way or another, but

I will say this, and that is the .20 calibre HW77K rifles I have tested here shoot very well indeed. I

also think that if the large range of pellet types was available for the .20 as it is for the .177 then it

could well live up to the claims of its followers.

So it you want an air rifleair rifle that is in-between .177 and .22 and that has a flat trajectory, accuracy

and obviously an energy level midway between these two calibres, I suggest that you take a good

look at the .20 calibre HW77K. The features, accessories and support that are available for the .177

and .22 calibre HW77Ks is still the same: basically the same rifle just a different barrel.

Those of you who already shoot the HW77K in .20, if you have anything to add on the positives (or

negatives) of this air rifle that I don’t cover within these four articles, then please email me and I

will share it with everyone.

The .20 Calibre HW77K  straight out of the box.

As with all new spring powered air rifles, whatever the brand, they take quite a few shots before

they start shooting that well. The first 100 shots are usually the worst while the seal beds in and

the spring develops a ‘set’ and then the barrel slightly leading up.

Furthermore, it is not just the air rifle that improves with time, it is you the shooter as you develop

muscle memory and familiarity with the gun.

The graph below shows all four calibres of HW77K firing the first 15 shots out of the box and then

some 50 shots later, another 15 shots. You will see that the Extreme Spread has reduced along with

the speed to a small degree, while grouping also improved. The tests were done using the H&N

Baracuda in each calibre of the HW77K air rifles tested. This clearly demonstrates that as the

HW77K air rifles put through more pellets they settle down and with a reduced spread, the

consistency will help you with grouping.

The speeds below are not set in stone so to speak, they are individual speed results and what you

see here may vary quite a bit from what you may experience yourself with a HW77K.

Gunroom HW77K Spread sheet Results

HW77K .20 Cal Spread sheet


Gunroom HW77K Energy Graph

HW77K Energy Graph for a .20 Cal


Graph for HW77K showing Extreme Spread

Extreme Spread Graph for a .20 HW77K


HW77K Speed Graph Gunroom

Average Speed Graph for a HW77K in .20 Cal


Should you Tune and air rifle or not?

In my opinion, yes. WeihrauchWeihrauch  HW77K air rifles are mass produced and while the machining

specifications are un paralleled, variances do exist in spring technology, compression pressures,

tolerances and bore finishes. In saying that, I haven’t come across a HW77K or any other air rifle

that I have tuned that didn’t benefit from a V-Mach Tuning Kit.

I’m guessing if you just throw a V-Mach Tuning kit into a HW77K without doing the prep work and

then shimming ‘up and down’ against speed an grouping results, then the benefits may be marginal.

As for speed, detuning the .177 and .20 from FAC down to 12 ft. lbs. or less, generally gives better

results as the recoil is reduced and with the better V-Mach spring and guide, more consistent

speeds are obtained.

I sell the V-Mach kits and can talk you through fitting them if that is the way you want to go, or if

you are buying a new HW77K or similar Weihrauch spring air rifle, I can tune it for you. If you

already have a HW77K, HW97K or HW80 and you want it kitted out, just send me the action and

leave the stock at home.

HW77KT Air Rifle

HW77KT in Stainless


As for results, I have fitted kits in .177 and .20 HW77K and HW97K air rifles that have reduced the

group of 42mm and 18mm respectively at 25 metres, down to 6mm groups. The .177 suffers from

hot loads and the .20 does also to a degree. By detuning your FAC air rifle down to 12 ft. lbs. you

won’t shed that much speed that it is screamingly obvious, only you will have an air rifle that is

comfortable to shoot and also performs as placement is more important than speed.

HW77K Summary.

I haven’t covered dimensions, weights or options for the HW77K in .20 calibre yet, but as all the

‘77Ks are basically the same, I shall cover these issues over the next 2 articles.

So to generalise the .20 calibre, I would say this: if you are going to get involved with target

shooting then give the HW77K in .20 calibre a good look, however, if you are a hunter then maybe

look at the .22 calibre if you want to shoot larger vermin like rabbits.

Author: Ian McIntosh