This report covers:
- The kit
- Trigger out
- Stop here!
- Job done
- Cocking effort
Today I install a Vortek HW50-PG4-Steel (7.5 ft. pound/10 Joule) Tune Kit in my .177-caliber HW-50S air rifle. If you remember, back in December of 2021 I installed a ProGuide4 Steel High Output kit in this rifle. It produced over 16 foot-pounds of energy with a Falcon pellet, but the cocking effort was raised from a factory 32 pounds to 37 pounds of force. That is way too much for a light rifle like this 50. In fact, after testing it here is what I said,
“Where does this leave us? Well, this HW 50S is shooting with far more power than I need. And it cocks with greater effort than I want to apply. At this point I wish I had bought the lower-powered kit instead of the SHO. Maybe with time the cocking effort will change.”
“The shot cycle is quite smooth, but quick. The forward jolt is still there but it’s greatly reduced.”
I quit shooting the HW 50S after that experience because it was too much work for too little return. And then when my HW-30S turned out so nice following a similar Vortek tune I figured I needed to try the lower-powered kit in the 50S. That thought was reinforced when reader RidgeRunner’s Diana 34 turned out so well with a lower-powered PG4 Steel kit installed. Oh boy, here we go!
The kit I received from Vortek looks like the one I’m replacing. The only difference is the spring wire is 0.113-inches in diameter instead of 0.119-inches for the wire in the high output kit. Hopefully that will make a big difference in the cocking effort.
As you can see, there is no appreciable difference in the length of the mainsprings between the two kits. The new lower-powered kit came with red grease instead of the brown grease Vortek used to supply with its kits.
I really dislike how the HJW 50S disassembles. It has four tabs (Weirauch calls them locking plugs) that must be pushed out of their holes to let the back block (Weihrauch’s name for the part the trigger and safety fit in) come free of the spring tube. There is also one tab on the back block that requires the whole block to be rotated to clear a notch in the spring tube. Removing this back block is definitely a job for a mainspring compressor.
The first thing to come out of the barreled action after removing the stock is the trigger. Press out the two cross pins to accomplish this. Then the Rekord trigger will slide out. And don’t forget the spring-loaded safety pin at the back of the spring tube.
Once the trigger is gone and the safety is removed the back block can be removed. That will be as far as we need to go on this rifle because a new 26mm piston seal was installed in Part 6
The four locking tabs (blue arrow points at one) must be removed first by pushing from the inside, then the back block is rotated until its tab (yellow arrow) clears the notch in the spring tube. That allows the back block to slide out of the spring tube.
Let’s stop right here because what I just showed in the three photos above is the secret to the disassembly of many of the Weihrauch spring rifles. The four tabs can be difficult to remove unless you know the trick. The trick is in two parts. First you adjust the spring compressor to take all tension off those tabs so they want to pop out easily when pushed from the inside. Combine that with the second part, which is to insert a pin punch through the spring tube holes where the Rekord trigger pins came out. As you adjust the mainspring tension you wiggle the pin punch to align the holes in the back block and the tabs will almost pop out on their own.
You can make a small tool to push the tabs out from the inside. I made one from a bent nail. An Allen wrench cut off on the short end makes a good tab pusher, as well.
What I just described makes the difference between a 5-minute disassembly and one that takes an hour. It takes practice, but it can be learned.
Once the old kit (shown in the first picture) was out I lubed the new one and slid it in. No need to disassemble the barrel from the spring tube. Then the assembly was the reverse of the disassembly, except it helps to cock the trigger to install it in the rifle. If you forget how that’s done, read it here.
Then put the assembled barreled action into the stock and the job is almost done. After the rifle is together don’t forget to pull the trigger or the rifle won’t cock.
Now just cock the rifle and test fire. Oh, oh! The rifle refused to fire. Did I need to disassemble the rifle again while the action was cocked? Nope. The safety sometimes gets its coiled spring wire stuck in the hole it passes through and that will stop it from being disengaged. Just press harder and it should go off. Point the muzzle in a direction you want the gun to fire (pellet trap) when you do this.
Where are we now? This rifle cocked with 32 pounds of effort from the factory and 37 pounds after installing the Vortek High Output kit. With the new kit installed it cocks with 32 pounds of effort. Well, that’s underwhelming. We’re back to the factory specs for cocking.
I wonder where the power is? With Air Arms Falcon pellet the factory tune averaged 810 f.p.s. And with this new tune the same pellet averages 902 f.p.s. Yep, this 7.5 foot-pound kit that has SMALLER wire (I measured it!) than the Vortek High Output kit produces 92 f.p.s. higher velocity than the factory spring that cocks with the same effort. It’s 98 f.p.s. slower than the High Output kit (1,000 f.p.s.). So this time Vortek missed the mark and gave me a 13.25 foot-pound rifle instead of a 7.5 foot-pound one.
I dislike the cocking effort! The shooting is reasonably smooth. and the trigger is adjusted to perfection — 2 stages that break at 14 ounces. But this isn’t what I wanted and I’m calling Vortek on it. On the other hand, if your R9 seems too heavy this might be just the airgun and tune for you.
We ain’t done yet. Somehow I think a wrong mainspring snuck into the kit, or the whole kit is wrong. We shall see.