B50 Screw #26

[DresdenHeep]

When I got the B50, I pumped it up to 2K psi and it locked up.  I forget how I got the pressure down for it to shoot but I did.  After that, I mentioned that in a post and someone said something about screw #26.  I'm no gunsmith and was reluctant to mess with anything but its sitting there unused and I'd like to be able to use it.  Can anyone tell me what to do with that screw?

[Taso1000]

Part #26 is a pin that keeps the hammer/striker from rotating.  You can operate the rifle without it.

Thanks,

Taso

[DresdenHeep]

Thank you.  Does it have anything to do with the gun locking up with too much pressure?

[WildCJ5]

Are you saying you don’t have that screw in the bolt? That can cause it to lock up. The hammer can rotate down and catch on the trigger.

It could also be your exhaust valve. The bam50 were way over powered with the hammer sling and will push the metal part right through the plastic exhaust.

Both have happened to me.

[DresdenHeep]

No, the rifle is intact.  I got one of the last ones available on the Continent--in Canada so I think it was tuned to shoot under 12 fpe.  I understood that if you filled it past a certain psi, that would cause it to lock up and that part #26 had something to do with it.  I should probably just call and see if Mac works on them. LOL

[demarisl]

Get http://www.lebedev.com/airgun/technical_details_for_adjusting_the_bam_b50_51.pdf if you don't already have it.  Link in the GTA Library doesn't work.

[DresdenHeep]

Yes, thank you I did have that link.  I guess I'll just take the screw out and see what happens.  Thank you all for your time and attention.

Ken

[WildCJ5]

You are local, take it to Mac1. Tim knows these inside out. They are simple rifles.

[Taso1000]

Ken,

If you got your rifle from the Canadian Airgun Forum Store, the two .177's that I've fired from there were running at full steam out of the box.  Unless Dan "Sniper" was detuning rifles?  I never knew it was an option.

To release pressure connect a hand pump to the fill foster and pump till you hear the fill valve on the rifle release and open the air path.  With the muzzle pointed up, as much as you can, slowly open the bleed valve on the pump.  If you open the bleed too fast the valve may be forced by the pressure and seal again.

You can do the same if you're filling from a tank.  Add pressure till the fill valve releases, close your bottle valve and bleed off the pressure slowly with your fill whips bleeder valve.

Don't go over the max working pressure of the gun though.

Another way to release pressure is to very slightly loosen the foster fill fitting.  Very little, 1/4 turn ish, to where you hear air escaping.  Be very careful and don't rush it as there's a lot of pressure involved.

Another thing that may have happened is that if left at max working pressure for a very long time, years, the poppet valve may have been forced into the firing valve like a cork.  The Canadian Airgun Forum Store rifles are "new old stock" and I don't know when they were manufactured but it was a long time ago.

Also as WildCJ5 stated, Tim at Mac1 Airguns used to sell and tune these rifles.  He tried to convince the factory to reduce spring and striker weights so that the rifles would not beat themselves up and last longer.  Also, never dry fire a factory stock rifle with zero pressure in the tank.  It will destroy the firing valve poppet.

I haven't messed with my B51's in a while.  I've gotten sidetracked with other projects!   

Thanks,

Taso

[moorepower]

Are you saying you don’t have that screw in the bolt? That can cause it to lock up. The hammer can rotate down and catch on the trigger.

It could also be your exhaust valve. The bam50 were way over powered with the hammer sling and will push the metal part right through the plastic exhaust.

Both have happened to me.

How is this happening? The hammer has a 360 degree sear surface. Lots of them not in the hammer with no issues.

[Ribbonstone]

You'll have to check.

That screw (#26) really only keeps the striker from rotating. It's a circular striker,so without the screw in place it could rotate when being cocked/fired(considering the torque of the spring, it likely would rotate.


Sometimes  the reciecer isn't really ound on the inside, the striker isn't really round,or it has worn a wear pattern during use that has made the fit not-round...could check for that, but gnenerally if it runs slick and smooth with the screw...use the screw.

The only other problem with screw #26 is that if you over tighten it,can kind of spread the screw slow...which makes it wider.  Is a prrtty tight fit, bugger it up and it can become a binding fit.

[Taso1000]

Part #26 is a pin that keeps the hammer/striker from rotating.  You can operate the rifle without it.

Thanks,

Taso

So my memory is wrong.  It is a screw.  People remove it to eliminate a potential binding/dragging in the slot that would affect hammer strike consistency.  Also with the screw removed you can adjust the striker throw a little easier versus having to also remove the barreled receiver.  The screw stops the striker from completely coming out of the tube if you remove the rear endcap.

I guess I had the Crosman striker and pin image in my mind.  I apologize.

Thanks,

Taso