I would like to try my hands on an Anschütz rifle. To see what it takes to convert the 7.5 joule 10 meter version to a 12 footpound / 16 joule Field Target rifle. I have already done a few Walther models (LG200, LG300 and LG400) and the Feinwerkbau P70.
In the past Anschütz produced a Field target version of this model. It was the model 2020 in 16 Joule / 12 footpound and the model 2025 in 21 joule / 15,5 footpound (fpe).
Anschutz stopped making these when the company acquired a majority share in the Austian company Steyr Sportwaffen this was around the year 2001. Apparently Steyr was to be the “field target” part of the new company and successfully so, looking at the number of Steyr rifles used at the Field Target world championships. See https://airgunaccuracy.wordpress.com/field-target-equipment-at-the-2015-world-championships/.
I got the chance to buy an Anschutz 2002 Compressed Air (2002CA). This is the first pre charged pneumatic rifle that Anschutz developed. It came on the market in 1997. A year after the Feinwerkbau and Steyr PCP’s were introduced and the same year that Walther released the LG200 PCP rifle. The 2002CA is based on the single stroke pneumatic 2002 Superair model.
Knowing that Anschutz build a field target version of this rifle, and that a few have been converted in the UK by Dave Welham and others, gave me the confidence that this new project could be successful. From various sources on the internet I also learned that it would take more effort than converting a Walther LG200, LG300 or LG400.
I will keep you posted on the progress. And show what’s needed to get the Anschütz 2002 CA to be an accurate field target rifle.
Unfortunately I could not find any spare part drawing or exploded view drawings of the 16 joule Anschutz 2020 Field Target rifle. I did find a cut away picture of an Anschütz 8002 S1. This 8002 S1 model has the same regulator, valve, valve block that the 2002 CA has (but a different valve spring guide). The difference is mainly in the triggerblock. The Anschutz 8002, 9003 and 9015 have 4 bolts that fix the barrelblock to the triggerblock.
The picture below shows the barrelblock (blue) and its parts. The yellow arrows show the path that the air follows. It’s clear from this picture that the valve chamber is very close to the regulator chamber. The valve chamber contains a spring to return the valve to the closed position. This spring sits around its spring guide, on the 2002CA the valve return spring sits inside a guide (see down below for pictures).
I found info on the internet that there is a lot of experience with Anschutz conversions in the UK. Dave Welham, Jon Harris, Tench/Simon and others have successfully converted the 10 meter Anschutz rifles to 12 footpound. Pieces of info on the work needed for a 16 joule or 12 fpe conversion where found at different places. Pimpmyairgun.com, airgunforum.net and of course the highly valued field target website http://www.shooting-the-breeze.com.
I puzzled these pieces together and with the invaluable help from Tench (thanks again, Simon) I found out what was needed:
- The regulated air volume is too small for 12 footpound / 16 joule and needs to be increased. To achieve this the barrel block needs to be bored, the regulator diameter decreased and the valve block can be modified.
- The output pressure of the regulator can be increased to get more air behind the pellet. Jon Harris seems to achieve 12 fpe / 16 joule without increasing the pressure. The reg pressure is factory set at around 68 bar.
- The cocking handle needs to be replaced by a model that will clear the scope and scope rings. This type of cocking handle can be ordered from Anschütz. I found one on http://www.eGun.de.
The Anschutz 2002 barrelblock has 5 holes through it. So the boring of the valve chamber needs to be done very careful not to bore into an existing hole. I wouldn’t want to bore too far and damage the 150 euro barrelblock.
Before starting to bore away in the barrelblock I thought it would be wise to make a drawing of the original block to be sure were all the holes are located. So I downloaded a technical drawing software and thought myself a bit of CAD drawing 😉
This is the resulting drawing:
This is a left hand cut away view of the 2002CA barrelblock. The stepped 15mm hole at the top is the hole for the barrel. The barrel is not in the drawing but it would point to the left. The red hole in the middle is the valve chamber containing the regulated air. The bottom hole houses the regulator. There is of course a hole connecting the regulator chamber and the air chamber above it. I did not draw the 2 holes for the screws that connect the barrel block to the trigger housing.
This is the drawing of the modified Anschütz 2002 CA barrelblock:
The red valve chamber has a much larger size and therefore a larger volume and can hold more air to propel the pellet.
When the valve chamber is bored out the original valve return spring guide will not fit. A new spring guide needs to be made to give the spring a secure seat in the larger and deeper hole. See the picture below.
To get a better airflow around the valve I bored the valve block t0 10mm diameter.
After I assembled the bored barrel block, valve block with the new valve spring and valve spring guide and the new cocking handle the rifle shot around 200 m/s ( 10.8 joule or 8 footpound). I adjusted the regulator. That’s a simple job on these Anschutz rifles because it can be set without disassembling the rifle. The barreled system needs to come out of the stock and the regulator setscrew can be reached with an allen key. It needed just over a full turn to get to 236 m/s (15.3 joule / 11.3 footpound).
The accuracy of this setup was moderate, say about 25 to 30mm 5 shot groups at 50 meters. I tried 4 batch numbers of JSB Exact.
I decided to free float the barrel to see what this would do for accuracy. The barrel is originally held very tight in the barrel holder by two M5 headless screws. And the barrel holder is fixed in the wooden stock. I enlarged the diameter of the hole by 2mm giving the barrel a 1mm space to move around in all directions. And off course I did not install the two screws that held the barrel originally.
This way the air cylinder is still fully supported and the barrel is protected against large bending forces that might knock it out of line when the barrel holder would be completely removed. Have to test for accuracy again, will keep you updated.
Testing for accuracy with the free floating barrel gave disappointing results. I tested several batches of JSB Exact at 50 meters distance but the 5 shot groups were 35 to 40 millimetre large.
When touching the barrel I noticed that it could move up and down and left to right quite easily when a little force was used. Apparently the bedding in the stock was not very solid. Normally the whole system of barrel and receiver/trigger block is tightly held at the front by the barrel holder. But because I had removed that front fixing point the single point bedding in the stock was not giving enough stability.
So I decided to create some extra bedding surface by using a method called “glass bedding”. It doesn’t have much to do with glass, but it uses a 2 component epoxy to sit between the stock and the rifles system block (receiver). It’s used a lot in benchrest rifles for instance.
I used Devcon Plastic Steel Epoxy that I bought on E-bay. Two small tubes of about 2 oz or 60 grammes. This was more than enough for this job. I think there is at least half the amount left in the tubes after the job was done.
I used some plasticine (kids playing clay) in the stock to make a ridge in front and to the rear so the epoxy could not run out of the desired place where I wanted it. I also put some masking tape to the sided where I did not want the expoy on the stock.
The picture above shows the expoxy after hardening with the plasticine (lighter gray) and masking tape still in place. The pip in the middle is plasticine that I put in the small hole in the barrel block. The aluminium ring you see at the bottom is the original Anschutz bedding area with the single bedding screw in the middle. Easy to see why the barrel and action could be pushed from left to right in the stock before the glass bedding was done.
I treated the barrel block of the rifle with a very thin layer Kiwi neutral color shoe polish. This prevents the permanent attachment of the barrel block to the stock. Otherwise the epoxy would act like a very strong glue and it would be impossible to remove the rifle action from the stock.
I removed the plasticine and the masking tape and bored a small hole where the pip was. This hole is meant to let the air escape when removing the air cylinder from the rifle. It takes the air pressure of the threads and makes it easier to unscrew the air cylinder.
The results where markedly improved after the epoxy bedding. The Anschutz 2002 now shoots groups of under 25 millimetre at 50 meters. I will post some pictures of the groups later.
Thanks for reading, Sven.