by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3

Diana 34P
The Diana RWS 34P is a classic breakbarrel spring-piston air rifle.

This report covers:

  • Happy birthday, America!
  • Vortek Pro Guide 2
  • Disassembly — Rail Lock Spring-Compressor
  • Spring break!
  • Removing the piston
  • Trouble
  • Lubrication
  • Assembly

Happy birthday, America!

Today the U.S. celebrates 241 years as a nation. It will be loud tonight (fireworks)!

Today I install the Vortek Pro Guide 2 tuneup kit in Geo791’s .22 caliber Diana RWS 34P. Now that we know his rifle is accurate it will be nice to also know that it shoots at the top of its form.

Vortek Pro Guide 2

Pyramyd Air doesn’t sell this kit, so if you want one you’ll have to get it direct from Vortek. The kit consists of instructions, a new mainspring, a special new spring guide, a synthetic top hat/forward spring guide, new piston seal, new breech seal and grease.

Diana 34P Pro Guide 2
The Vortek Pro Guide 2 kit comes with everything you need to tune your Diana 34.

The mainspring in this kit appears to be made of good spring steel. I know that Diana has had problems in the past from over-hardening their mainsprings, so this tuneup should ensure George a long time of good operation with his rifle. The piston seal is also special and I will cover it in a little bit.

The new spring guide fits around the outside of the mainspring instead of the inside. You may remember that a coiled mainspring expands slightly when compressed, so this guide will become tighter rather than looser when the gun is cocked. As the kit comes, the guide is already on the spring extremely tight, so there isn’t going to be any vibration in this area!

Disassembly — Rail Lock Spring-Compressor

To fit the kit the rifle must first be disassembled. I used the Air Venturi Rail Lock Spring Compressor to remove the mainspring. This is the second type of action I have used the Rail Lock on and it works like it was made for Dianas!

Diana 34P Rail Lock Compressor
The threaded rod of the Rail Lock Compressor spans the Diana safety and presses in on the back of the trigger — exactly where you want it!

Once the compressor was in place, I put a little tension on the trigger block and both pins that hold the trigger block in the spring tube came out. The action came apart in seconds, making this the fastest I have ever disassembled a Diana. The Rail Lock is the reason for that.

Diana 34P spring relaxed
The trigger block is pushed out this far by the mainspring. All tension is off at this point.

Spring break!

Now the spring guide and mainspring could be removed and, once they were out, I saw something that I have seen many times before. The mainspring was broken about one inch from the end on the spring guide end! This is a very common fault with Diana spring rifles, though I thought they had corrected it in the past decade. The unbroken end of the mainspring has a small cant in it, as well. So, George was lucky that I decided to tune his rifle! I actually wrote a report about this in 2006 titled, Spring Break.

Diana 34P spring break
A broken mainspring is a common Diana fault. They typically break about an inch from the end like this. Notice the last coil on the other end is canted.

Remove the piston

The next step is to remove the piston. The barrel has to come off for this, because the cocking link must be separated from the piston body. Dianas are made to come apart easily this way and I had the barrel off in less than a minute.

Diana 34P powerplant parts
All the powerplant parts are out of the gun.

Trouble

The piston seal in the rifle was like new, but since the Vortek kit has a new one, I removed the Diana seal. Getting the new Vortek seal back on the piston, though, was not easy. It took me all of 45 minutes. I found that the seal material likes to be warmed by flexing, before it will hook the flared top of the piston. But I got it.

Diana 34P piston seal
The Vortek piston seal is made from different material than the Diana seal, plus it has a groove around the circumference. That groove prevents lubrication from migrating forward from the mainspring.

Lubrication

I lubricated the piston seal (very sparingly), the rear of the piston body and the mainspring with the special grease that came in the Vortek kit. The Vortek owner, Tom Gore, tells me this piston seal will wear in to become incredibly slick with use, so it doesn’t need much lubrication.

I put a bit of extra grease at the mouth of the spring guide, since I couldn’t get the mainspring out to lube all of the coils. Cocking the rifle will spread this grease back on the back coils of the spring.

Assembly

The rifle went together just like it came apart. Once more the Rail Lock compressor was easy to install and operate. I discovered the Vortek spring was a little longer than the factory spring that had the last inch broken off.

Diana 34P assembly
The Vortek mainspring is ever-so-slightly longer than the broken Diana spring.

The last job was to replace the breech seal. The old one looked fine, but since the kit came with a new one, I installed it.

Start to finish this job took 2 hours. That time includes taking pictures and 45 minutes fiddling with the piston seal.

After that I finished the assembly and went to my range to test-fire the rifle. How did it do? That’s coming tomorrow.