HW 30S
The HW 30S.

Part 1
Part 2
Part 3
Part 4 — Rekord trigger
Part 5 — lube tune
Part 6
Part 7
Part 8

This report covers:

  • Is the Weihrauch mainspring bad?
  • The Vortek kit
  • Vortek grease
  • Vortek piston seal
  • The welds
  • Check for burrs
  • Assembly and lubrication
  • Don’t do this
  • Assembling the barrel to the spring tube
  • Lube the end of the cocking link and the slot in the piston.
  • Install the pivot washers
  • Install the Rekord trigger
  • Summary

Today we install the Vortek PG3 SHO tuning kit in the HW 30S. There was a big surprise along the way, so I made today a complete tutorial.

As you remember, in Part 8 I disassembled the HW 30S, thinking I could give it a lube tune and compare that with the Vortek PG3 SHO kit I planned to install next. But on the discovery that the mainspring was bent, I decided to go straight to the Vortek kit. I had to buy it direct from Vortek, because Pyramyd Air was out of them at the time. As a result I had the chance to talk to Tom Gore about the kit a little.

Is the Weihrauch mainspring bad?

I have read several comments that the Weihrauch mainspring ends are not ground properly, plus a You Tube video makes the same comment, so I first decided to take a picture and show you what this one looks like.

HW 30S mainspring end
The mainspring that came out of this HW 30S was perfectly ground flat on both ends, and one coil was collapsed, which is just as it should be.

The Vortek kit

The PG3 SHO kit from Vortek consists of a spring guide, a mainspring and a tophat. The spring guide has another guide down inside that keeps the mainspring from kinking as it’s compressed. There is also a  small plastic jar of grease that you are supposed to only use a third of when lubricating the new mainspring. I will have more to say about the grease in a moment.

I also bought a Vortek piston seal on Tom Gore’s recommendation. I know what some of you are thinking — he sells them so of course he’s going to recommend them! And no doubt that is the case. But I have used many Vortek piston seals and I know they are superior to what the factory puts out.

HW 30S Vortek kit
The Vortek PG3 SHO kit with the Weihrauch piston.

HW 30S Vortek spring guide
There is a second spring guide deep down inside the rear guide that fits outside the mainspring. This one keeps the spring from kinking inside the rear guide as it compresses. The white threads you see are threads of the special grease Vortek uses.

Vortek grease

Tom Gore told me to stick my finger into the grease in the kit then pull it out and watch what happens. So I did. The grease clings to the finger and draws out in a long tenuous string. 

HW 30S Vortek grease
The Vortek grease clings to things with tenacity!

Vortek piston seal

I also bought a piston seal, so the factory seal had to come off the piston for the new seal to go on. I stated prying the factory seal with the blade of a pocketknife, and once there was room I got a screwdriver blade underneath. The factory seal is soft and it pried off easily.

HW 30Sfactory seal off
The factory piston seal comes off easily.

Now it’s time to install the new Vortek seal. In the past these seals have been hard and difficult to install, but this one went on right away. This seal is chamfered underneath where it fits over the piston head and that chamfer guides the seal to a good fit. 

Once on the piston the seal is loose enough to rotate easily. In my experience that’s what you want, unless there is a specific reason not to (like alignment of the air transfer port with a part of the piston — I’ve seen that once). The HW 30S has no such reason, so this seal will probably still be with the rifle at my estate sale.

HW 30S Vortek seal on
The Vortek seal went right on. The seal rotates easily.

Shop Benjamin Rifles

The welds

Reader Yogi made a disparaging comment about the welds on the bridge that keeps the cocking link parallel with the piston. I looked at the picture and had to agree. So I promised to take better pictures so you could see the welds more closely.

HW 30S weld 1
This weld is ugly as sin, but it penetrated the steel and will hold. Probably put on by a novice welder.

HW 30S weld 2
The other weld is ugly, too. But it may have flowed better.

The bridge is on the spring tube to stay. And the ugly welds hide beneath the stock.

It’s time to clean the powerplant and install the kit. I already cleaned the piston so the new seal could be installed.

I use some paper towel wrapped around thin screwdriver blades to get into tight spots like the inside of the piston. And a long screwdriver blade gets the inside of the compression chamber. There was very little grease in any of these places..

Check for burrs

After cleaning I run my fingers around the cocking slot and every other hole that penetrates the spring tube, checking for burrs. There were none on this rifle. That means Weihrauch left it in the tumbler long enough for the media to get rid of all the burrs left by machining before the tube was blued.

Assembly and lubrication

Now it’s time to put the kit into the rifle. Unlike other tuneup kits I’ve installed, this one slid right in with no obstruction of any kind. That was probably because there were no burrs, as I mentioned.

The Vortek spring is shorter than the factory spring, so it goes into the spring tube deeper.

HW 30S Vortek kit in
The Vortek kit slid into the spring tube deeper than the factory mainspring and guide.

HW 30S end cap Vortek
Here is how far the end cap slides into the spring tube with the Vortek kit installed.

HW 30S end cap out
And this is how far the same end cap stuck out with the factory mainspring.

Don’t do this

And this is where old BB went wrong. I assembled the spring tube all the way to completion with the Rekord trigger installed before it dawned on me that I couldn’t put the barrel on that way!

HW 30S powerplant assembled
Don’t do this! I was going to show you a clever way to avoid using a mainspring compressor, but I forgot that the barrel had to be assembled to the spring tube before the end cap was installed.

Assembling the barrel to the spring tube

You see, to assemble the barrel to the spring tube, the cocking link needs to push the piston back just a little. If it doesn’t, you can’t get the hole through the base block (where the pivot bolt goes) all the way into the forks of the spring tube. You can get it to within fractions of an inch, but it won’t quite align. So BB had to take out the trigger and the base block at this point and use a mainspring compressor for the final assembly. If you have two people you can probably make do without a compressor, but that little screw that holds the end cap against the mainspring is difficult to align and start for one man, if he’s also fighting the mainspring.

Lube the end of the cocking link and the slot in the piston.

HW 30S cocking link and piston slot
The end of the cocking link (shown upside-down here) fits through the bridge and into the enlarged hole in the spring tube. There is no separate sliding “shoe” for the link to attach to. I lube all contact points with moly grease. You can drive the pin back through the bridge at any time after this is done.

Install the pivot washers

Weihrauch uses paper-thin steel pivot washers on either side of the base block, where the pivot bolt goes through. I lube them with Moly grease, as well as the inside of the pivot bolt hole and the outside of the bolt. It’s a little fiddly to get both washers in with the base block, but the moly holds them in place and a small screwdriver or pin punch will move them to where they have to be.

HW 30S pivot washer
Put moly grease on both sides of each pivot washer, through the pivot hole and on the outside of the pivot bolt.

Now bolt the barrel to the spring tube and tighten it. The barrel needs to stay in place wherever you put it after the gun is cocked, so that pivot bolt needs to be tight. But don’t over-tighten the nut on the other side! Once assembled, the rifle can go into the mainspring compressor for assembly of the end cap.

HW 30S mainspring compressor
The rifle is in the mainspring compressor to install the end cap.

Install the Rekord trigger

Now that the rifle is assembled, it’s time to install the Rekord trigger. I lubricated the sear with moly grease in the last report, so it is okay. To install the trigger I like to cock the trigger, just so it goes in its slot easier.

HW 30S Rekord trigger uncocked
The Rekord is uncocked.

HW 30S Rekord trigger cocked
The Rekord is cocked so it will go into the end cap easier.

Install the trigger pins, pull the trigger (because you put it in cocked) and the barreled action is assembled. Now install the barreled action in the stock. Then cock it, insert a pellet and fire. It cocks easily, it shoots smoothly and it feels right. Job done!


There were a lot of steps in today’s report, but I found the Vortek kit very easy to install. It was the rifle that threw me a curve. Now that I have warned you — you can avoid my mistake.

I had hoped to test the velocity of this tune today, but when I made my blunder it cost me a lot of time backing up. So this is the end of this report, and I’m not sure I want to test velocity next time. 

Perhaps next time I will test accuracy with another peep sight and then test velocity after that. That will give this tune a chance to settle in.