Still Messing With the Benjamin 3030

I’ve been busy with my visiting family but I did mess around a bit more with the Benjamin 3030.

There’s about 1/8” of slack between the point where the cartridge is contacted by the piercing pin and the hammer. Thus the valve opens up a lot more than I think is needed.

So I made a rubber spacer…

Installed.

It still pierced the CO2 cart, but not as much.

However the spacer slid and got between the hammer and the trigger (you can see the indent).

There’s a hardened steel insert in the hammer that the trigger engages. I only got a few more shots over the paltry 10 I was getting though so I pronounced it a failure, at least for now.

Then I thought about the hammer spring. Right is the “original” but probably not stock hammer spring. Center is the replacement I dug up, and left is an even weaker replacement I found in my big box of springs. I may need to make an even weaker one.

I also added an o-ring to the valve where it contacts the tube. I doubt that’s why there’s a groove there but I noticed that the valve was sliding back and forth a but as the hole in the tube that the screw sits in was larger in diameter than the head of the screw. Obviously the solution is to make a screw with a larger head…

Anyway I managed to get 20 shots with the weaker spring. Which is not a success, but lets me know that I’m on the right track. I think if I keep the valve from moving altogether I may see a slight increase as well. I think the hammer hits the valve, knocks open the seal, but then the entire valve body rebounds and bounces a but, preventing the seal from closing in a timely fashion. Or I could be wrong, which is likely. I also suspect that gas is leaking around the barrel, through the valve body and into the space between the hammer and the valve body, as well as the shot tube – sometimes the bbs bounce out of the loading port, but I don’t know if it’s the rebound or a gas leak.

The goal is the advertised “up to” 30 shots, so if I could just get it up around 25 I’d be happy. I still need to run it across the chronograph but it’s been raining for a week.

Benjamin 3030 Reassembly, Part 1

Putting it back together…for now…

Drilling the exhaust seal.

Turning the OD.

Facing.

Boring for the screw.

Cut off, next to old seal.

Not too happy with the face.

Inserted a new o-ring in the valve body.

Reassembling, used a spent CO2 cart to push the innards in.

All together. It works…but not well. The valve is staying open far too long, leading to that dreaded “braaap” sound and only yielding 10 shots per cartridge.

I forgot the screen,maybe that’s the problem? Nope. Didn’t change how it behaved when I replaced it.

The barrel comes back pretty far to knock open the valve. Perhaps I’ll try a shim between the hammer and valve and see if reducing that depth helps.

Also the valve seat is worn, probably a good idea to clean it up.

The holes the piercing pin makes in the cartridges is pretty large, I think reducing the hammer strike will also limit that hole, which could be good or may not matter. It’s possible the pin is sticking in the cartridge as well.

The main spring has a rough end. Maybe it’s a replacement?

I substituted a shorter spring. It behaved exactly the same. So at least I know it isn’t that?

I’m wondering if an even shorter spring would be good as that’s how much preload there is – the bolt hole still isn’t visible in the slot. But I think that the valve face could be the culprit. We’ll see.

Benjamin 3030 Disassembly, Part 4

Just about done.

Stock screw removed.

The bent c-washer captures the screw so you can take down the rifle for transport.

This is a rough approximation of how it loads.

BBs are inserted into the tube.

When the muzzle is raised a BB rolls into the valve assembly.

Without the barrel in place it’s easy to see how the magnet works.

The BB captured by the magnet.

The barrel at the receiver end. 4 ports for gas flow.

Again, a BB dropped into the hole is stopped by the barrel.

When the rifle is cocked by moving the hammer forward the BB drops down. When the rifle is fired the barrel moves back, picks up the BB and knocks open the valve.

As you can see here, the barrel sticking through the valve chamber would have knocked open the valve and gas would flow through the ports and propelled the BB out the barrel.

I think I may just clean the 3030 and see if I can get it to work before thinking of any refinishing. Now where’s my 5 gallon steel pail?

Benjamin 3030 Disassembly, Part 3

On I go…

I took up the force of the hammer spring by holding the safety (smaller of the two screw headed posts) back and unscrewed the cocking handle.

Again I pushed down on the bench which took up the spring force and allowed me to remove the safety post.

Here’s a shot showing how the end of the barrel protrudes just past the housing.

With the safety post removed the barrel comes out.

Followed by the hammer spring.

The hammer is soldered to the barrel. Notice the revolving cutaway ring, that’s for the safety post and allows it to be rotated into the slot in the housing.

A collar is soldered on the barrel as a stop for the hammer spring, which is captured between it and the front (muzzle) of the housing.

Removing the safety ring. I rotated it and it dropped down.

The o-ring in between the brass and the spring needs to come out.

I pushed down on the spring so I could dig the o-ring out. It was rock hard, which is undesirable in an o-ring.

With the o-ring removed the valve spring can come out.

The now disintegrated o-ring and valve spring.

Then the exhaust valve drops out.

That’s a heck of a piercing pin.

The screen removed. I don’t see how it does much to capture debris?

The exhaust valve face. The flats on the larger diameter allow the CO2 to flow around the open valve.

The piercing pin unscrews.

The seal comes out easily. Not sure what it’s made from. I may try and see if it works before making a replacement.

A typical valve seat inside the valve.

More to come…