2100 converted to .22 cal

[plinker99]

 i finally got my $40. reman 2100 converted to .22cal
  i used mrod barrel #2263-001.  used a drill & file to turn the breech down to about 3/8" when the oring in the breech came through.  it worked out quite well as after removing the oring channel, the transfer port on the barrel support & the barrel lined up with just enough space for the oring to fit to seal the bolt.
   i drilled out the barrel support to just fit the turned down breech end.  then drilled out the breech to 7/32" then used a chain saw file to get the load port & magazine to fit a .22 cphp. 
   for the bolt, i used a a short piece of 7/32" od brass tubing epoxied to the 2100 bolt.
   the barrel band needed the little tit trimmed to clear the larger diameter barrel & the front sight needed to be drilled out to fit the larger barrel. then a few layers of electrical tape to support the barrel in the housing.
    i used hot glue to seal the leak in the barrel support,  & replaced the clipped hammer spring with a new one, here's some chrony numbers using cphp 14.3g.

pumps  fps
3      414.9
4      473.1
5      525.2
6      534.2
7      581.5
9      589.7 & 598.3
10     610.0 & 606.1
12     630.9
15     653.2
20     669.5

   i'm thinking that this will work out quite well.  i'll shoot most of the time 5-7 pumps.
   next will be some work on the trigger.

   here's a pic of the parts modded.
   thanks to big bore bart & K.O. for their input.  i still need to get the math figured out,  some day.

[Big Bore Bart]

    Great work!   Knew it could be done.      Now go into the valve and replace the spring, the stock one is far too heavy.    You'll get your 14 fpe with fewer pumps, and may even get to 16 fpe.   Also will help out at lower pump #s.

[K.O.]

Hail yeah,  way to go,  coolest part is it should be very accurate and none of that pellet fussiness since the barrel is choked,  yep not bad at

all...

[cwlongshot]

Nice work!  ENJOY iT!!

CW

[plinker99]

   bart,  thanks for the tip on the spring.   i tried a softer spring that i had.  it pumps easier but the fps is still the same. it still pumps without needing to be cocked first, so i'm thinking that i can go with a softer spring.  i'll try to find another spring for it.  one thing i noticed after converting to .22, it's a lot louder than a stock 2100 in .177.  has a sharp crack!! sound.

   K.O.,   i tried to zero my 4x20 tasco scope on it & it hits single holes a lot.  but not where i'm aiming.  the adjustments don't change like you would expect.  i'll put a new 3x7x20 tasco that i got & it should be better.  i got one on my stock 2100 & it's accurate enough for me.  so far i'm only using cphp's & they shoot quite good.
 
   cw, thanks for the complement & the incentive to try this.  by any chance, do you have any chrony numbers for your 2200 magnum?  i'm interested in seeing how this compares to it.
    thanks.
plinker99

[Big Bore Bart]

   Did you match the porting to the M-rod T-port?    Take them out to ~.160".     You'll see good gains.

[plinker99]

bart,
     if my conversion is correct, .160" is about 5/32".   the mrod barrel port was slightly smaller than 5/32. i drilled it out to 5/32.  i also drilled out the barrel support tp.  so i got 5/32 on the valve, tp & barrel.   i didn't angle the valve port.  i'm pretty sure there's no leaks as when i took it apart to change the spring,  i didn't see any signs of oil inside the receiver.
    i was thinking of going bigger, to 11/64" but thought that was too risky for now.

thanks.

[Big Bore Bart]

    5/32 = .156 so close enough.      You say it has a "craaack" to it.   Download SoftChrono, and shoot a few shots, not for the velocity, but for the sound pattern.     It may be you need a Disco spring, as you may have hammer bounce.   SoftChrono shows the wave form and all the rifles sins show up.

[BerkshireHunter]

If Crosman brought back the 2200, Id buy it in a minute.

[Big Bore Bart]

If Crosman brought back the 2200, Id buy it in a minute.

   I'd buy three or four, they are good great for tinkering.

[K.O.]

If Crosman brought back the 2200, Id buy it in a minute.

I do believe I have said that also...

I would pay a good bit more if it was up to the first gen 2200s and had a good piston with a wiper.

[plinker99]

   Well guys, I used to think I would get a 2200 if crosman started to make them again.  After converting this 2100 to .22 now I'm not too sure.

   Bart, I got softchrono working & can see the shot wave form.  I'm not sure what I should see or look for.  I recorded a shot with audacity & got a similar wave for it.  After shooting today,  the sound is not so much a crack.  More like a low pop. Seems like the sound  reflecting of my trap behind the crony has a different sound than shooting to my 10 yd target    I still need to get another spring for the valve.  When I get it & change it, I'll try the adjustable piston that I made.  Something changed since now the pump arm wants to drop open at 5+ pumps.
  More later.
   Thanks.

[Big Bore Bart]

   Hammer bounce will show up as another spike (or two or three) right after the main shot.    As for the pump arm falling, have you pinned the valve yet, and what are you using for a pump pivot pin?     This is what hammer bounce looks like.   You can see the two impulses after the shot, and before the impact.

[plinker99]

Bart,
     Thanks for the picture. I tried to get  a similar waveform but so far no success.  I got the mic @ 5' & a can @ 10'.  I need to get a longer cable so I can move the mic out to 10' or 15' & the can out to 20' or 30'.
      As for the pump arm,  I'm using the stock roll pin.  I have not pinned the valve yet.  A post that  K.O. directed me to gave me the idea of using the tp to lock the valve to the pump tube.  The od of the last part of the valve port is slightly bigger than 1/4".  The hole in the pump tube is about the same.  I'm thinking of making a brass insert that will lock the two together.that should keep the valve secure.


 

[Big Bore Bart]

  My mic is at 16.5' and a 14 ga steel plate is at 33'.   Gives a nice clanngggg,   Two or three set screws just behind the T-port, into the valve body, is the best way to pin the valve, drill, tap, twist, and no more shift.

[plinker99]

   today i tried to get a shot waveform from softchrono & still no success.  could be where i'm shooting has too much echo since if i fire with no pellet softchrono shows 714fps or 1040fps depending on what i set the max fps to be.
   anyway i swapped the stuffed piston with the adjustable one i made.  i adjusted it a little more than 1/16" longer than the stuffed piston.  the pump arm stays locked better now.  i think i can still adjust it to make it longer.  there was some gains over the stuffed piston.  strangely on the second round of chrony testing, the numbers dropped & the pump arm got looser.  i'm thinking that i need to adjust it again & pin the valve.  here's the numbers using cphp 14.3g.

pumps     1st pass     2nd pass
3                422.8          415.1
5                532.3          527.0
7                596.0          584.3
10              653.5          630.7
12              660.4          640.7
15              682.7          650.0
20              683.4          671.1


    another thing i discovered....
    using my bathroom scale, so this this is just ballpark figures,  the original valve spring opens around 7-8 lbs.  the striker spring puts about 3-4 lbs. on the poppet end at rest. the spring i'm using in the valve opens around 5-6 lbs.  this spring allows pumping without needing to cock the gun first.

   here's pics of the adjustable piston.