HW 50S: Part 4
This report covers:
- Remove the stock
- Trigger comes out first
- Remove the 4 tabs
- Tabs not under tension
- Tab tool
- Remove the end cap
- Remove the mainspring
- Spring bent?
- Barrel off and piston out
This is a reminder that tomorrow BB Pelletier will be taking the American holiday of Thanksgiving off. So there won’t be a new blog. I will be back on Friday with a new one. Happy Thanksgiving!
Today I take the HW 50S apart to install the Vortek PG3 tune kit. I discovered some interesting things as I went, including something I have never seen before, so come along and watch.
Remove the stock
The first step is to remove the barreled action from the stock. Since the rifle has only one forearm screw on the bottom, there are just two more stock screws in the triggerguard to remove and the action comes free of the stock.
With the stock off I saw that the HW 50S end cap fastens like the R9 end cap. Four tabs must be driven out before the end cap can be rotated inside the spring tube to clear the small flange that holds the end cap in the tube. I don’t like this system because the first disassembly is always harder. Confused? Follow along.
Trigger comes out first
Step one is to drift out the two crosspins and remove the Rekord trigger. After it comes out don’t forget the safety and its coiled spring.
The Rekord is lubricated with the same thin Weihrauch grease that’s on the inside of the powerplant. When I install the tune kit I will clean and lubricate the trigger like I did for the trigger of the HW 30S. Since I wrote an entire report on just that I won’t do another one this time.
It’s impossible to see that all the silver parts except the trigger blade are covered with a thin coat of Weihrauch grease. Most of of the grease (except for what’s on the piston hook on the left) will be removed and the sear, in the window at the bottom right, will receive moly grease.
Remove the 4 tabs
The next step is to remove the four tabs that prevent the end cap from turning inside the spring tube. They don’t hold the end cap in the tube against the force of the mainspring. That’s done by a very small flange at the rear of the cap. But if that flange should rotate when the last tab is removed, the mainspring will launch the end cap, so it’s time to break out the mainspring compressor and make the job safe.
The end cap is inside the spring tube, so I use a long socket to push on the center of the cap while I’m removing the tabs. And here is a word to the wise.
Tabs not under tension
The four tabs are not under tension from the mainspring. So you don’t need to push on the end cap at this time. In fact, pushing makes the tabs harder to remove — ask me how I know, ha ha. The small flange at the rear of the cap holds the cap inside the spring tube against the mainspring. So get the action in the compressor securely right now, but put no additional tension on it.
You do need a tool to push out the tabs because they have to be pushed out from the inside, where the trigger was. A small Allen wrench with a short leg will work for this, but all my wrenches had legs that were too long. So I grabbed an old nail and made a tool by bending the end. Insert the small end of the tool in the tab hole from the inside of the end cap and use a screwdriver to press on the back of the tool. With a rocking motion on the tool the tab will come out.
Tabs do not come out easily the first time they are removed. But as they are removed and replaced time after time they wear in and get easier to remove.
Once a tab on one side pops out, use a thin pin punch through the tab hole to push out the tab on the other side. That’s easy.
Remove the end cap
Now we discover why the barreled action is in the mainspring compressor. It’s time to remove the end cap and let the tension off the mainspring. To do that put a little more tension on the end cap with the compressor and push the small flange out of its notch in the spring tube. A thin-bladed screwdriver behind the flange is perfect for this.
Now, use the mainspring compressor to put a little tension on the end cap. Then rotate the flange out of its slot.
The flange is out of the slot, allowing the end cap to be removed from the spring tube. This picture shows the small angle of the slot and the corresponding angle of the flange that ensures it will not rotate out while it’s under tension.
Relax the compressor
After the end cap is free to move you can relax the tension on the mainspring compressor. The cap will back out of the spring tube almost two inches.
Remove the mainspring
You can now pull the end cap out of the spring tube. The spring guide and mainspring will come out next.
You may remember that there was some buzzing in this rifle during testing and I thought it was due to a bent mainspring like we had in the HW 30S. When I examined the spring outside the rifle, though, it rolled straight. Only the last coil on the spring guide end seems to be bent and not very much. I’ve never seen just one coil out of alignment like this.
If this coil really is out of alignment, it doesn’t seem to be out enough to have caused all the buzzing. I think the buzzing was caused by general loose tolerances of the powerplant parts. Fortunately I will be replacing the spring with a new one from the kit.
Barrel off and piston out
The barrel pivot bolt can now come out and the barrel will come off the mainspring tube. Then the cocking link can be removed from the piston and the piston slid out of the tube. This is necessary because I bought a new piston seal with the kit.
Well the rifle is apart and that is where I’ll leave it today. Next I will install the Vortek kit and we’ll see what happened.