Project Fury 20mm BIGbore. 3100FPE!

[MJP]

That is one impressive airgun Marko! I love how calm you remained and were when you told your buddy "that was something broke". I had to chuckle a little.

Thanks,
After history of drag racing and building engines for racing you get used of stuff happening when pushing the envelope. No point loosing your cool about it, it's already broken.
After all failure is a learning experience, you get to build it better.

Marko

[bear air]

Oh so very true sir.

[MJP]

So had some time to fix the rifle, balancer cylinder broke in two as valve buffer broke and the valve bottomed out on the cylinder head.

All is fixed and made a slight modification to prevent that from repeating.

Marko

[bear air]

Looking forward to some more videos. That thing is awesome!

[MJP]

Thanks Chris,
We will shoot some video next weekend, have stuff to shoot at, old helmet, harddrives etc..

Marko

[sb327]

Looking forward to seeing the vids !

Dave

[MJP]

Lets start by adding a statement to this, ALWAYS WEAR SAFETY GOOGLES!
Now that is out of the way, and yes I did wear mine. And that saved my eye for sure.

I have not been a fan of the two lever guns, bolt and separate cocking handle. It's an accident waiting to happen, and so it did happen. 

7mm steel safety pin on the bolt sheared clean off, and sealhead and O ring was gone somewhere.


What happened is I effed up somehow, cocked the hammer and at that point always secure the bolt with my thumb while holding the cocking lever. Just a routine to make sure it's locked.
But this time I noticed that I forgot my safety's and reached out to grab them from the table.
Either my hand hit the bolt handle and accidentally opened it or I didn't close it. No matter what but routine was disrupted and the bolt was not locked all the way or was completely open when I pulled the trigger.

Reconstructed picture after the shot.


That Tikka cheek rest and safety pin saved my head, it directed the bolt down and slowed it enough that I only have a bruised cheek and got a mild concussion. Felt like being hit in the head with a heavy fist. 

Every failure you walk away from is a learning experience, and I won't be shooting the rifle before it is modified so that it is impossible to actuate the valve when the breech is not fully locked.

I have feared what would happen if this freak accident of discharging the gun with the bolt open happens but thought that I'm careful enough always... clearly I was wrong, and it just takes that one split second disruption in your routine.
So stay safe and always wear the glasses, and be mindful of the danger of big bore airguns.

Marko

[sb327]

I’m glad you’re ok! Whew, bet that was scary.

Thanks for sharing, keeps us all humble.

Dave

[Mr.P]

Yikes - the way that stock piece trapped the bolt is a small miracle. Or maybe it reflects your choice of durable materials…

 Been checking this thread every time it updates - what a great project. 

[bear air]

Glad your okay. That's some scary stuff right there. I applaud your tenacity and humility Marko. Thanks for sharing.

[JuryRigger]

YIKES!!!! 
Glad you're OK, sure reminds you to keep those layers of redundancy in whatever you're doing! 
Jesse

[Rob M]

thank god youre okay! thats some serious force trying to eject the bolt.

[MJP]

Thanks guys,

There is some risks involved when pushing the boundaries, but when stuff starts to get downright dangerous it's time to rethink and redesign the system.

Can't rely on the human factor, needs to be foolproof it seems. Have made some things that way so I don't trust anyone else to operate them but it seems it includes myself too.

Well season is about over in the north amongst penguins and polar bears or what ever people thinks walks in here. Fall is here and shooting will about stop for the winter.
We will post some video of the fun from weekend. How many 4-5 liter water jugs it takes to stop a 20mm airgun? It takes about four to stop a  fifty cal BP as the bullet shatters on impact.

Marko

[bear air]

Sounds like your going to have some drawing board time. Good luck.

[rkr]

Scary, good to hear that you are OK - it could have been much worse.

[rsterne]

Glad to hear you are OK, Marko!.... It's not the static pressure you have to worry about with a bolt, it is the momentum the bolt has after accelerating backward until the air vents and the pressure drops (over 100mm, by the looks of it).... Lloyd did a great study on this, and the strength of the shear pin required on your Monster would be considerable.... Certainly a 7mm pin doesn't come close, if the gun has any possibility of being fired without the bolt being locked down.... A learning experience for sure.... 

Bob

[TPL]

It was propably the best possible outcome from insident like that you can imagine.

So many details where you were lucky.

[subscriber]

At some power level implementing a disconnector seems like a great idea.  A mechanical switch, interrupt or block that prevents firing, if the bolt is not fully closed and locked.  Standard on most PBs.

[MJP]

Long winter to make changes.
I uploaded short video on YT of season ending fun.


Marko

[jackssmirkingrevenge]

Good thing you specified that the frying pan was non-stick

Truly impressive effect on target, particularly the hydrostatic shock from the melon and jugs on the chair and table structure respectively.  That incompressible fluid is transmitting a lot of power.