$40 reman 2100

[plinker99]

 following cwlongshot....
   i got the new $40.00 remanufactured 2100 last month.  i finally got a chance to mess with it.  it has a number of issues out of the box......
1) the cocking bolt lever/arm is super tight. it feels like it will break off to cock the gun.
2) i ran it over my chrony & got really low numbers.  my other 2100 @ 3 pumps gets about 550 fps.  this new one got 255-290 fps.  i did my leak test & the bolt leaks big time.  after seating a cphp it too leaks.  the pellet is not seating quite right.  i took out the pump & found the plastic pump rod twisted & slightly bent.

   i figured i got this 2100 to convert to .22 cal. so i'll just fuss with it as it is.  i ordered a mrod .22 cal barrel & a bunch of other parts yesterday.
   in the mean time...
   i got #1) fixed or at least better,  i found that the bolt knob has a little tab next to the spring that is a little too long.  that causes the bolt to bind making it hard to cock.  another post recommended to loosen the screws holding the receiver halves together.  while this helps, filing the tab really fixes it.  what is happening is the back end of the receiver tapers slightly & when the bolt is pulled back it jams on the tapered area.  filing the tab gives the bolt the clearance needed. another thing that was making the cocking hard is the hammer spring seems to be binding when compressed.  it almost feels like the spring is too long or the diameter is slightly bigger than the older 2100 i have.  i did not get a chance to compare the 2.  anyway, i clipped about 2 turns off the hammer spring & reformed the end.  that made the cocking better.  i can still feel a binding when the hammer is just about to latch up.  i got a new spring on order.

   as for problem #2) i trimmed the valve nose a little.  this one was really pointed.  i tried something different on the pump cup.  i punched out a little disk from a tire tube & super glued it inside the cup instead of shimming the back side.  the twist & bent pump rod seems ok for now.  i'll do something with it later.  i'm thinking of just using another rod or tubing to replace the bent part.  that way i won't have to worry about the cup end & the link end to the pump arm.  i  think that will do it for the pump/valve for now.
    for the  bolt/probe, i pulled the magnet out a bit & did my leak test with a pointed pellet & it's not leaking when seated.  the pointed pellet has a deeper skirt than the cphp.  next is the bolt seal.  for now i just wound 3-4 turns of #22 guage bare copper telephone wire supper glued in the grove just back of the magnet probe.  then coated it again with another layer of supper glue & left to dry.  after drying, slight sanding for a snug fit in the breech. big difference on my leak test.  while not a total seal, it's ok for now.  after getting it back together, shot over the chrony shows around 500 fps.with 3 pumps. so it's quite close to my other 2100.
    i may do some trigger work while waiting for my parts order to arrive.
    more later.
plinker99

[Big Bore Bart]

  I am going to presume you have a lathe, 'cause you're gonna need it.    The barrel support will need to be bored for the barrel and for the larger pellets.  The Mrod barrel will need to be turned down slightly as the max the support should be taken to is ~3/8 id.  The 2100 "magazine" will need it's channel enlarged for the .22 pellets.     The best way to seal the breech end of a 2100 barrel is to install an O-Ring between the barrel and the barrel support.
http://www.network54.com/Forum/275684thread1379450609

Flat-top valve caps are available.
http://www.gatewaytoairguns.org/GTA/index.php?topic=54854.0

And there are other mods that can be done.
http://www.network54.com/Forum/275684/thread/1388948735/Are+there+any+Mods+for+the+Crosman+2100-

As you can see, I've given this conversion a lot of thought myself.

    HTH   Bart

[plinker99]

bart,
   thanks for the reply.
   first of, i don't have access to a lathe.  i was afraid that would be needed for this. but anyway i'll try & see what can be done when i get the parts.
    as for the .22 bolt, i made a flow through bolt probe for my other 2100 & it seals quite nicely.  i am planing to use the same setup but add on a larger tube for the .22.  the load port & magazine will need to be enlarged & i'll figure out something.  since it's plastic & pewter?, i'm thinking it should not be too hard to drill it bigger somehow.

   anyway i'll see how it goes.

    one more thing about the reman 2100 i just remembered,  the barrel to barrel support also leaked air a lot.  i used 2 wraps of regular clear scotch tape & it worked just fine.  i tried plumbers teflon tape & electrical tape with no success.

    i 'll try to get some pictures as i progress with this.


plinker99

[K.O.]

When I first picked up my 2100 30$ used the first thing I did was see about turning it into a 2200 and found that Crosman did not carry the

parts oh well  then I thought about modding what is there and decided that it in my opinion it would be better to just buy one they still can be

found it may take a while but...


 The other route would be similar to how I plan to do my 1325 and that is just use a 1322 breech and trigger group of your choice and make a

 1322XLT.

It is simpler than what I am trying to do because the stock valve would do fine for .22 in fact I bet it would hit about 650 fps pretty easy...

But

It would not look like a 2100...

[Big Bore Bart]

  I just had a thought about the Mrod bbl, you will have to measure the ID of the O-ring groove, it may limit the amount removable from the OD.      As for opening the mag-support channel, a chainsaw file comes to mind.    The support is a zinc alloy,and the mag is nylon?.   I use Loc-Tite gasket maker to seal my bbl-support, a little smear allowed to set then installed, the stuff remains flexible and the set screw compresses it.

[K.O.]

Teflon did work on mine... huh

My pump rod was bent also but I stuffed it the other day and it will be use in my project for a while it is strait now.

mine was bent because the pump cup was pinned and was about .05 proud of the piston and the valve nose was also long.

once I fit the valve to the cup and let the cup seat all the way back in the piston I got lucky and it fit just right.


"i tried something different on the pump cup.  i punched out a little disk from a tire tube & super glued it inside the cup instead of shimming the back side."

Did you do this to fit the cup to the nose.  I would be worried about it coming  loose...

I just make sure that the leading edge of the cup hits very slightly before the nose hits the center otherwise there is just a bit of headspace.

Imo   

I still like the 2100 power plant but the execution is not what it use to be.

I would not mod an older 2100/2200/766 into a 13xxXLT but for the newer ones well honestly...

Change bolt and barrel and transfer port, easily to go between calibers is also a feature...

Just my opinion...

[plinker99]

bart & k.o.,
   thanks for the ideas.

k.o.
  i've been following your 1325xlt posts.  that's a lot you have to do.  but the end result sounds like a winner.
   i tried teflon tape to seal the barrel but it always got snagged.  same thing with electrical tape.  the scotch tape worked on this one.  on my other 2100, i used hot glue on the barrel before inserting it into the support.  that's working for now.
   as for the pump cup, i did trim the nose a bit.  i didn't measure how much. i'll keep an eye on it to be sure it stays put.  i have stuffed the piston & shimmed the cup on a 1377 after trimming the nose of the valve.  that gave me some great numbers.  i just thought i'll try something different, easier too.
   i was trying a 2289 for a .22 but like the 1377 i got, it jumps when i pull the trigger.  drove me crazy like a springer rifle. i thought of modding it to be like a rifle but the short pump stroke led me to the 2100.  so that's where i'm at now.

bart,
   i had a similar thought like you about using a chain saw file to size the load port to .22.  as for the barrel work, i need to wait till i get it to figure how i'll get i mounted.
   i saw quite a stir on the green forum about a cheap 2100 pcp.  i also saw that you have a build on the way for one.  i'll be following that one too.  thanks for sharing.
   by the way, for that build, i was thinking how about mounting the original 2100 pump with the valve side facing the muzzle?  that way plumbing to the fill valve will be shorter.  depending on the working pressure needed, it could be a self contained pcp.

[cwlongshot]

Neat project!!

 Mine is OK... I have had two pellet stick in the bore... never shot it with less then 8 pumps. I THOUGHT it leaked, but it holds air for weeks at a time...  ALL where the copper plated pellets I use for the rats... Maybe I should stay with lead.

Best of luck with yours!!!

CW

[Big Bore Bart]

Here's the thread with pics on the PCP.
http://www.gatewaytoairguns.org/GTA/index.php?topic=58868.0

[K.O.]

I think you probably plan on doing it but  here is a thread I saw about drilling the little tit or taking it off of and making a transfer port in order

to enlarge the port from  .140 to .160-.170 or so which I think the .22 needs... 

http://www.network54.com/Forum/275684/thread/1199223049/Bob+Dole,+2100+transfer+ports-

[K.O.]

Right now for me the hardest part is waiting on parts...

[plinker99]

Hi CW,
   Thanks for the tip on the $40 2100. 
   Did you have a chance to get any chrony numbers for your 2100?  I'm interested in seeing what you get at 3, 5, 7, 10 pumps.  I usually shoot my 1st one @ 3 pumps & get around 550 fps.  If you don't have the numbers, don't worry about it.
   As for the pellet getting stuck, i was thinking that it might be the transfer port seal getting loose during the shot.  I read somewhere a while back that the seal between the barrel & valve can get loose from the high pressure pulse that actually lifts the barrel away from the seal.  I have seen signs of this on my 760.  There always was oil sprayed inside the receiver in that area.  I used a zip tie to strap the barrel to the pump tube to keep it from separating.  Eventually I used some brass tubing to make a longer transfer port that gets inserted more into the valve so if the pressure moves the barrel, there still is a seal.
  Just my $.02.

[plinker99]

K.O.,
   Thanks for the info for the tp.  I knew i would have to enlarge it for .22 Cal.  That gives me a starting point.
   The wait for parts is on.  Crosman said 2-3 weeks for my order. I hope it's sooner.

[plinker99]

Since the wait for parts will be a while, today I decided to see what stuffing the piston will do.  To set a baseline I shot each #pumps twice.  I did 1-10, 15, 20.  After stuffing did 2 shots @ 3, 5, 7, 10 pumps.  Then 1 shot @ 15, 18, 19, 20.  My arm was getting shakey by this last bunch.
  K.O. was right about the rubber disk that i super glued coming loose from the pump cup.  I found it when i pulled the piston out to stuff it.  I just left the cup alone for the testing after stuffing the piston.  Here's the numbers. All using crosman pointed pellets @ 7.4g......
      Before.                After
1 - 298.3 & 293.0
2 - 428.7 & 425.9
3 - 488.0 & 503.1.       531.1 & 530.7
4 - 549.0 & 550.2
5 - 579.5 & 580.7.       618.3 & 628.1
6 - 609.3 & 606.7
7 - 624.1 & 623.1.       698.2 & 692.3
8 - 626.0 & 636.7
9 - 637.1 & 636.3
10 - 644.3 & 648.0.      739.7 & 738.5
15 - 669.0 & 659.0.      758.8
18 -                                770.9
19 -                                  770.3
20 - 675.1 & 675.9.       503.?/137.5 this one retained air for the second shot @137.5

So stuffing the piston did make a difference.  I think there is still more I can squeeze out of this one as I feel a puff of air coming out of the bb magazine slot on shots with more than 5 pumps.

[K.O.]

The really telling shot is at 10 pumps.
it puts it back to about what the older 2100s got
mine was shooting 690s pre stuffing.

Almost 100 fps gain it shows how much the stiffening  the floppy piston improves the pumps efficiency at higher pressures...

It also looks to top out at 16 pumps ( much smaller gains after) I am guessing about 15-1600 psi  and wonder if you might have just a tiny bit of headspace or if it is the practical limit of the cup system..

The math says these should get 1500-1700 psi in ten pumps but as pressure rises efficiency drops how much I do not know?

85% at 800 psi  50% at 1300 ? 

Thanks for posting I stuffed my piston but did not shot after and this tells me that it will do what I needed for my project...

I was pretty sure but it is nice to see real results!

[plinker99]

k.O.,
     I may have a little more headspace that can be removed as I think I may have trimmed the valve nose more than I should have.  The pump arm does not lockup as tight as on my other 2100.  Eventually I'll mod the pisrton to make it adjustable  & see how that goes.
    Thanks for your observations & tips.  The math part looks interesting.  I'm still trying to understand how that works.

[Big Bore Bart]

   The math is standard compression ratio stuff, and it works better in metric.    (Pump area x stroke + valve volume)/(valve volume - headspace) =CR.    CR x 14.7 = pressure rise in the valve per stroke.  P/R x # strokes = theoretical valve pressure.  Theoretical pressure x pump efficiency = valve pressure.    I personally use ~65% as a pump efficiency fudge factor.    Calculating the actual pump efficiency is not doable with out a gauge in the system.

 Are we here yet?            Bart

[K.O.]

This is close to the fit that you are looking for.

http://www.network54.com/Forum/275684/thread/1211140448/1211339438/some+interesting+valve+stuff+for+pumpers+%28Pics%29

Just a touch of squish area works best and you can see that there is a bit of leeway limited by how much you can collapse the cup.

I used a drill bit that fit perfect instead of the roll pin while testing fit and actually was unlucky that I was lucky when it fit with no headspace...

I wanted to have to shim a about .04 that way I could double wrap a Daisy 853 wiper in that area to give it back a wiper like the older versions.

I works very well in my 13xxs. 

[K.O.]

I will probably if need be just take that much off the front of the piston to be able to install a wiper.

there was a good size difference in fps between freshly oiled and 10-15 pumps later on my 13xxs  and the wiper evened it out and now it also I am sure gets less oil into the valve and of course it is longer between oiling...

 also the 2100 showed a bigger difference in fps if it was freshly oiled or not...

[K.O.]

Bart I want to steal your thunder  and use it with,


I want my parts yesterday

At least Crosman lets you know 7 to ten days

BnA  just sent your request has been received and charged my card no shipping confirmation yet...

And once I get the valves then off to you then back to me and then I finally get to see if I got it right???

Maybe I just need a "have patience grasshopper" from some of the gurus here like you...