2100 PCP Build

[Big Bore Bart]

   I started collecting parts for this project in Nov., and started cutting metal about three weeks ago.    So far I have made the end plug with integrated fill, and the reservoir tube/action tube.    I started on the valve, and then decided to go in a different direction with it.  So back to the lathe for it.     Today I started making a Maple butt stock.     Still to go is final pinning of the valve and end plug, a new barrel support/ air stripper, (yes it'll be invisibly shrouded), barrel band, and the fore end.   I hope to test fire within the next two weeks.
 
    Here are some pics.   

[JTB530]

Cool stuff Bart! Can't wait to see more.

[Rex]

I'll be following your progress with great interest.

[one_shot]

interesting...I was just reading this article on a $100 pcp from a 2100b.

https://www.pyramydair.com/blog/2014/01/building-the-100-precharged-pneumatic-air-rifle-part-2/

[Big Bore Bart]

     Well I finally got the time and tooling to get back to this.      Had to find a #5 counterbore then reduce the pilot to .104" for the valve and fill plug retention screws.       Got it put together Friday afternoon and took it to the paintball field to fill.(no tank or pump yet)   It leaked out the fill port.     But it dry fired even with over 4k in the tube.     The tube is designed for a 3:1+ safety factor at 4500 psi.   I started the dry fire tests @1500 and went up in stages.     Brought it home, tore it down and made a new Teflon fill plug check seal and inspected the valve seating.    I had made a steel on steel valve, and the body is too soft.   So I also made a new Delrin and tool steel stem.   I had company for the day today and by the time they left and I reassembled the rifle, there was no time to go for a fill.      In the morning I will go test again.     The wood stock is not yet done so I currently only have a factory plastic one on, with no fore-end.
     The manager of the field also invited me to bring some pellets and other guns for some GS removal.      

     Some pics of the parts.


The valve


  The fill/end plug


  The bolt probe


  The end plug in place showing the retention.

[jmdavis984]

Is this project at all related to what Tom Gaylord and Dennis Quackenbush just worked up?

https://www.pyramydair.com/blog/2014/04/building-the-100-precharged-pneumatic-air-rifle-part-6/

[Bryan Heimann]

Pretty cool project.  Do you intend to modify it so that it is still capable of shooting BB's?  I have thought of drilling a small hole big enough to pour BB's in front of the spot where the spring/follower are in the BB magazine so a wood stock can be added without losing the capability of loading BB's directly into the mag.  Also- will the bb magazine still function properly with lead balls, or does it rely on the magnetized probe and steel projectiles to prevent double feeding or dumping the whole mag?

[Big Bore Bart]

    It works!!!    Filled to 4500 psi shots started at 720.   It started to wake up at 3400psi, 895fps with 9.68 gr Winchesters.  And it stacks them.   I forgot to take my phone for pics.      I'll shoot some more groups later when I put a better scope on it.  But the little 4x Crosman was good enough for today.  (off to the hunting gate)

Is this project at all related to what Tom Gaylord and Dennis Quackenbush just worked up?

Nope.   I came up with the idea last October and started collecting parts then.   I was originally going to convert a 2200, but wound up with a 2100 first.

Pretty cool project.  Do you intend to modify it so that it is still capable of shooting BB's?  I have thought of drilling a small hole big enough to pour BB's in front of the spot where the spring/follower are in the BB magazine so a wood stock can be added without losing the capability of loading BB's directly into the mag.  Also- will the bb magazine still function properly with lead balls, or does it rely on the magnetized probe and steel projectiles to prevent double feeding or dumping the whole mag?

   No more BB's for this rifle.  The BB mag follower is gone, as is the detent and the magnet.

[Bryan Heimann]

The sweetest 2100 on the block! 

[Big Bore Bart]

The sweetest 2100 on the block!

  Thanks   The guys at the paintball field thought it was pretty cool too. 

[Matt15]

How many shots do you get per fill?

[Big Bore Bart]

How many shots do you get per fill?

  That's a good question.   I haven't finished the tuning yet.   So far 20+, it's just now getting down in pressure and starting to have serious hammer bounce.      It's bouncing so bad it sound like a Minigun in burst mode.    I'm trying to do a bstaley, but the striker has a long nose.   I have been into it three times, and still haven't added enough O-rings.

[K.O.]

 

Did you use the straw barrel?

[Big Bore Bart]

Did you use the straw barrel?

   With two bushings.    At the paintball place it was stacking the pellet splats.    I'll have some more chrony data in a bit, gotta add another O-ring to the stack.

[Matt15]

Hey just curious how much it cost to build? How will you fill it up besides the paintball place?

[Big Bore Bart]

   Build cost, The materials are under $50.00, not counting the base rifle.    The labor is where the cost would be.   Figuring I have over 12 hours on the lathe making the parts, at a lowball wage of $25.00/hr that's $300.00.    If the parts were made by CNC, the cost could be brought waaayy down.   As the programming cost can be covered by quantity.

   As for filling, a follow forum member has made an offer that can't be refused.   He's sending some non-working handpumps for repair, and I get to keep one.    I am also collecting material for a conversion project involving a Datsun Z20 engine.

[Big Bore Bart]

   Last testing for a few days, I'm outta air.      I finally made a sleeve, added three O-rings and got it to stop burping.   Chronied it and it was shooting at 504, pulled the O-rings and it's at 545, took .010" off the sleeve and it shot 502, the next shot was 498, then 489.     I think when this thing is tuned, it'll have a monster shot count.    I'll be very happy with 17-18 fpe for 20+ shots. 

[K.O.]

Man I wish we where next door neighbors...

[Bryan Heimann]

Stilll waiting to see that stock... Is it finished?

[Big Bore Bart]

Stilll waiting to see that stock... Is it finished?

 

   The stock's on hold until I get the mounting bracket done.   I'm currently using a factory plastic one.  The plastic one is actually better at this time, as I've had the rifle open almost as much as it's been together.    Tuning is change this and test, change that and test.     

  I am at the point of going to a shorter main spring as the striker bounce is horrendous.