HW 30S : Part 8
The Mendoza sporting peep sight is mounted too far forward on the HW 30S.
This report covers:
- A couple updates
- Removing the mainspring
- Mainspring out
- Why is the spring bent?
- Tune in a Tube?
- Removing the piston
- One more thing
- State of factory lube
- State of TIAT
Today we disassemble the HW 30S and see what’s what. You will remember that this rifle was a little buzzy when new and I tuned it with Tune in a Tube through the cocking slot. That is all that has been done to this rifle, other than shooting it. It’s also helpful to remember than the first time I tested the velocity in Part 2 it was slow, shooting Falcon pellets at an average 601 f.p.s. After some shooting in Part 5, they averaged 647 f.p.s., so a small break-in occurred.
A couple updates
You also remember that the trigger was too light in the last accuracy test? I discovered that the aluminum adjustment screw had backed out all the way and needed to be reattached. The trigger blade was just flopping around.
And remember that the Mendoza peep sight didn’t adjust low enough? Reader RidgeRunner suggested that I try mounting the AirForce peep sight from the Edge, which I did. It fits fine and is super-adjustable, so after the tune I will test it.
The Edge peep sight fits the 30S fine. Hopefully it will adjust low enough.
Step one is to remove the barreled action from the stock. The 30S has a single screw in the bottom of the forearm and two triggerguard screws. Then the action comes out of the stock.
The barreled action is out of the stock.
Step two is to punch out the two pins holding the Rekord trigger assembly in the rifle. Then the trigger and the safety and spring come out.
Punch out two pins and the trigger assembly, safety and safety spring come out.
Removing the mainspring
Now for the hard part, which is not hard at all, if you know the “secret”. You don’t need a mainspring compressor for this. If you are careful, you can safely remove the mainspring without a compressor.
The HW 30S has an internal end cap that restrains the mainspring, not unlike the HW 95 and Beeman R9. But on the HW 30S, this end cap is held in the spring tube by a single small screw.
That single screw (arrow) holds the end cap against the mainspring.
Obviously the mainspring is under some tension. What you do is place something to cushion the end cap when the screw releases it, then carefully unscrew that screw while pressing down on the barreled action.
I used an old piston seal. But anything that will cushion the end cap will do.
An old piston seal cushioned the end cap when the retaining screw was removed.
The end cap came out of the gun about 2-inches when the screw released. It’s almost all the way out, but not quite.
That’s how much tension was on the mainspring pushing against the end cap when the retaining screw released. That’s the screw above the spring tube.
With the end cap out the mainspring slides right out. Oh, oh! There is a small kink in the spring. That’s where the small amount of buzziness came from. If you can’t see it, when the spring is rolled on a flat surface it becomes apparent.
The mainspring is canted (bent)! I pointed to the area with the pin punch, but you should be able to tell without that. The bend is gradual, and to the right of where the pin punch points. This spring is toast!
Why is the spring bent?
If you are going to be a serious airgunner, this is a lesson you need to learn. Making and hardening a coiled steel mainspring is something of an art. Ask anyone who has ever tried to make a spring of any kind and they will tell you there is a very fine line between too soft and too brittle. You try to harden the spring within those parameters. When you make hundreds of the same springs, a couple are bound to be outside either limit, like this one. It is too soft in the area where the bend is.
Is this common? Not really, except I have experienced that many Diana springs are slightly too brittle at their ends, which makes them break off.
So, whaddaya do? Well, I chose not to get a replacement Weihrauch mainspring. I could have bought one and it probably would have lasted for many years, but I was going to install a Vortek PG3 SHO spring kit in this rifle anyway. This became the right time and I ordered one.
Pyramyd Air was out of the Vortek kits for the R7/HW 30S so I went straight to Vortek. I also ordered a new piston seal on the recommendation of Tom Gore, the owner of Vortek. Until the kit arrives the rifle will not go back together.
I will also tell you that the factory mainspring was loose on the spring guide. That helped me decide not to replace the factory spring, because I would have to do something about the loose plastic guide.
Tune in a Tube?
I found that the small amount of TIAT that I put into the rifle was more or less evenly distributed around, with the least being on the coils that are inside the piston.
Removing the piston
We are not done with the disassembly yet. The piston still needs to come out so we can examine the piston seal. To get the piston out the barrel has to be removed from the spring tube. The pivot nut on the right side of the barrel and the pivot bolt on the left side need to come out. If you break the barrel open the tension on the pivot bolt will be released.
On the right side of the barreled action remove the barrel pivot nut and washer.
Flip the gun over and unscrew the pivot bolt. If you break the barrel open the tension on the pivot bolt will be released.
Now the base block and barrel slide out of the action forks, revealing the thin base block washers on both sides.
With the pivot bolt out the barrel and base block slide out of the action forks.
One more thing
If this was a conventional breakbarrel you could now disconnect the cocking linkage from the piston, but on this rifle there is a steel bridge in the way. Remove the pin from this bridge and the cocking link pulls away from the piston. The HW 30S has no cocking “shoe” like other Weihrauch rifles. The end of the cocking link connects directly to the piston.
Drive that silver pin out of the bridge to allow the cocking link to withdraw from the piston.
With the barrel separated it’s possible to pull the end of the cocking link out of the piston and slide it back out of the bridge.
Now remove the piston. The cocking link was all that held the piston in the spring tube, so it now slides right out.
The piston slides right out.
State of factory lube
The rifle I have was lubricated well from the factory. I don’t care for the thin grease they use, but they never know where in the world their rifle may be going. I’m sure they selected something appropriate for everywhere.
State of TIAT
The Tune in a Tube was applied ultra-thin, yet it coated the mainspring very well. It did not get on the piston, nor does it need to.
That is a complete disassembly of the HW 30S powerplant. Even if I hadn’t planned to scrap the factory spring, I wasn’t going to assemble the rifle in this report. I will take my time and show you all the things I look for and do. I have some experience with those Vortek kits, having installed a couple of them, and I am anticipating a smooth tune with this is finished.
I know the Vortek kit produces more power than the factory 30S, but that’s not what I want. I want smooth shooting and easy cocking. Anything more than that is a waste, in my opinion. We shall see.