Diana Air King 54 Pro - Incomplete cocking cycle or bear trap issue

Well, I went ahead and disassembled the air rifle.  Everything looks spot on from what I can tell.  Nothing appears broken or bent.  Nothing out of place.  Piston and rod all seem to be attached and no excessive play anywhere.  This one has got me stumped.  Everything went back together and still the same behavior:  after cocking, I cannot move the cocking lever closed because it catches on the last stop on the bear trap.  Pull the lever back a little, release the bear trap, sear catches and I'm ready to fire.  Don't have a chronograph, so can't really tell if I'm getting an incomplete stroke and losing fps.  Doesn't seem to be any loss of power.  Still dead on at 50 yards.

Time to send it off somewhere?

Thanks,

Thomas

seeing that the trigger assembly either captures the piston rod end or it doesn't 

i have read this many times and i can't figure out if the rifle is cocked and will not return because of the bear trap, or because it is not cocked, and the second effort cocks the rifle and clears the bear trap

after cock there should be no pressure on the cocking arm at all but blocked by the bear trap 

in theory the bear trap could be removed altogether it is just a safety feature 

Hi Mike!  Agree....I thought about just filing off some of the last edge on the bear trap also.  This would fix my clearance issue, but kinda would like to know what happened?  I just don't see how it's physically possible for this behavior to even be happening.  Only thing I can rationally think of is the piston and piston rod assembly have gotten loose/elongated somehow.  But the "play" seems minimal to me, but wouldn't take much to start catching on that bear trap.

@marflow The cocking lever will not return because of the bear trap.  It is always cocked on the first attempt. Only issue is just can't close the cocking lever until I take pressure off the bear trap.

so, question 

you always have to press the bear trap down to secure the barrel closed 

so, has it been closing without the bear trap being pushed down in the past

SIDE-LEVER — Before returning the side lever to its original position, depress
the cocking safety lever (see illustration 4b) on the left side of the cylinder.
Grasp the side-lever, close to its original position. NOTE: There should be
NO pressure on cocking lever when returning it to original position. If there is
pressure, the air rifle has not been fully cocked.

Posted by: @essickt

↑

Well, I went ahead and disassembled the air rifle.  Everything looks spot on from what I can tell.  Nothing appears broken or bent.  Nothing out of place.  Piston and rod all seem to be attached and no excessive play anywhere.  This one has got me stumped.  Everything went back together and still the same behavior:  after cocking, I cannot move the cocking lever closed because it catches on the last stop on the bear trap.  Pull the lever back a little, release the bear trap, sear catches and I'm ready to fire.  Don't have a chronograph, so can't really tell if I'm getting an incomplete stroke and losing fps.  Doesn't seem to be any loss of power.  Still dead on at 50 yards.

Time to send it off somewhere?

 

Thanks,

Thomas

An OEM T06 piston should measure 7.070"± 0.010 from end to end.

If yours is measuring more than that, let me know and do not shoot the gun.

THANKS!

HM

@hector-j-medina-g Hi Hector!  Thanks for that info.  Time to disassemble again and measure.  Here is a video of the behavior:  Cycle the charging handle and sear engages but cannot release the bear trap.  Pull back slightly on the charging handle to relieve the pressure, sear stays engaged and charging handle closes.  No spring resistance on the charging handle.  Rifle fires and anti-recoil mechanism functions.

@essickt 

Please, please, please, measure the piston.

THANKS!

HM

is the bear trap adjustable for engagement 

wouldn't the bear trap if unscrewed a half of turn from where it is, drop the engagement level when fully depressed 

Hector,

Finally got some time to measure the piston.  Seems mine is 7.1. difficult for me to measure that precisely, but there is some significant play.  I can pull the central shaft out quite a bit.  Here are the photos.  About 1/8 inch variation in length when pushing in the shaft by hand and then pulling it out.  That seems significant.

Posted by: @essickt

↑

Hector,

Finally got some time to measure the piston.  Seems mine is 7.1. difficult for me to measure that precisely, but there is some significant play.  I can pull the central shaft out quite a bit.  Here are the photos.  About 1/8 inch variation in length when pushing in the shaft by hand and then pulling it out.  That seems significant.

-- attachment is not available --
-- attachment is not available --
-- attachment is not available --

 

Dear Essickt, thanks for the pictures and the measurements. Please accept DIANA's apologies, this should not have happened. We are sorry that it happened to you.

1/8" variation! Yes, that is significant.

PLEASE, do NOT shoot it.

Look for your proof of purchase (it can be an electronic .PDF receipt)

You have two options:

The lengthy one: 1.- Go to:  https://blueline.global/warranty

Read all the terms and conditions and follow the blue button to the warranty claim form. Fill the form enclosing all requested documents (proof of purchase), and they SHOULD tell you to return the gun.  They MIGHT want to tell you that you opened the gun and therefore the warranty is no longer aplicable ("Product modification or disassembly beyond field stripping will void the product's warranty."). If that was the case, it will be a lengthy process to get someone's attention.

A Shortcut: 2.- Contact BLS directly at: 

Warranty@blueline.global 

and tell them you have a faulty piston (loose stem).

Send the pictures you have posted here as well as a scan of the proof of purchase. It might also help if in the pictures, you include a picture of the "Caution" engraving where it states that this particular rifle was distributed by BLS.

Tell them that you feel this is a safety issue in a part where the user CAN HAVE NO IMPACT, and therefore it was a problem at the manufacturing stage.

Request (in a polite way, of course) a replacement piston.

Let's hope it will be easier for them to simply send the piston than to go through all the hoops and loops.

Keep us posted!

HM

Thanks Hector!  For me, time is my most valuable asset right now.  Yes, I could warranty it perhaps, but if I just wanted to quickly buy a new piston, where is the best place to request that?  I've seen some websites offering replacement pistons.

Thomas

Thomas;

If you commit to send me your defective piston, I can send you a re-worked DIANA piston (it's new, but the curve at the rear of the bell was causing problems with some slightly longer than normal compression chambers, so it had to be ground a bit). Tested, and it is in perfect working order. New Piston seal.

Just pay for the shipping of BOTH pistons (yours to me and this one to you).

I will then send the defective piston to DIANA, as this is something we had discussed in the past and, "measures had been taken". Clearly, the "measures" are no longer being followed, or something slipped.

I'll make sure that the Tech CEO takes this up with the production floor.

It is the ONLY case of manufacturing defects that REALLY makes me shiver. EVERYTHING else is just a "bother" but this one does make me shiver.

If you agree, contact me through my webpage: https://www.ctcustomairguns.com/contact-us.html

We will then proceed over EMail.

Thanks!

HM

Thanks Hector. Contact sent on your web page.

Posted by: @essickt

↑

Thanks Hector. Contact sent on your web page.

Part picked up by Postman today.

Keep me posted.

HM

@hector-j-medina-g 

The replacement piston from Hector has resolved the strange incomplete cocking issue!  Thank you Hector!  Defective piston and your shipping expenses are heading your way tomorrow!  Thanks to Diana airguns for supporting Hector!