Crosman 2100b with just a old style metal piston

[K.O.]

Recently I picked up a trio from a member.  pistol carbine and rifle.

The rifle was a 2100b.  I finally got caught up on my projects and had time to check its performance.

Stock its performance was a bit on the low side

pumps     fps

6            548
8            576
10          605
12          600

that was with 7.9 CPHP the 7.4 points were  Consistently about 30 fps higher.

I have a couple  of the old style 2100/2200 metal pistons and so I finally had the chance to install one.
I did not stuff the 13xx portion of the piston.
I did not match the nose of the valve to the cup.
I did not use the old style cup that matched the valves nose (The one I have is old and hardened)

I just installed the piston.

pumps      fps
6             610
8             664
10           710
12           737
15           762

with CPHP 7.9g  the   7.4 points were 20+ higher

Of course pump effort was increased and pretty stiff after  10 pumps.

So if you can make a piston or do a good job of stiffening the plastic piston it is well worth it and you do not even have to open the receiver...   

[K.O.]

I wish the aftermarket guys would pay some attention to  the 2100b just an adjustable piston and extended valve nose would get these shooting very hot.

Bart showed what a flat top can do

Me I like the larger valve volume  I feel it stresses the whole works a little less...

I do not understand why pumpers have been crippled rather than developed  I guess they are afraid that if the sell a honest 800 fps pumper for 75-100$

it will hurt the PCP sales...

[vigilandy]

Hey KO.  I just took delivery of an older 2100 (with the pinstripe).  Just like my old one.     Love seeing your posts about these guns.  Will need to run it over the chrony soon to see how it compares to your numbers.  Thanks for posting those.

[Matt15]

I bought a Flat top piston from Bart and  I am waiting on my o rings. Should be here next week.

[K.O.]

I bought a Flat top piston from Bart and  I am waiting on my o rings. Should be here next week.

and valve...?

[K.O.]

Hey KO.  I just took delivery of an older 2100 (with the pinstripe).  Just like my old one.     Love seeing your posts about these guns.  Will need to run it over the chrony soon to see how it compares to your numbers.  Thanks for posting those.

Considering I did not  open the receiver to address the valve to breech leak(it does can feel it coming out the bottom of the receiver) it is  doing durn good... probably leaks at the bolt a touch also...

[K.O.]

Leaks will be addressed when it tune it to be its best.  I will also be doing leade/breech/barrel work at that time

It only likes the 7.4 points at this time they are the only pellet that is feeding well into that area. It could be misalignment  or sharp rifling edge or ?

Using a seating tool it is very hard to get any thing but the 7.4s to seat past the port. very heavy pressure then it breaks past and seats the plastic tool I made will not do it it takes an allen wrench...

I also have not made barrel stabilizers yet will do that within a short while...

The barrel only needed the tiniest bit of tape at the front sight...

I did quick 5 shot groups with 7.4gr and 7.9gr Crosman pells at 25 yards I bet from what I said you can tell which is which.

it shows that just with the stabilizers it will stack pellets and shows  signs that with attention to detail it will respond very well to tuning

its new-reborn first groups pics ( 4x15  tasco still at pre piston install 20 yard zero)

[avator]

Does Bart have any more of the F/T piston and valves? Any idea how much $? I guess I could ask him. Just curious. We have a couple we put nice walnut stocks on. Sure would be nice to upgrade a bit.

[K.O.]

Oh the Groups are standing side rest I still do not bench even though I know for testing I should...

[K.O.]

Does Bart have any more of the F/T piston and valves? Any idea how much $? I guess I could ask him. Just curious. We have a couple we put nice walnut stocks on. Sure would be nice to upgrade a bit.

Honestly do not know but it was a pretty small run so it would not surprise me if they all sold...

[Matt15]

Does Bart have any more of the F/T piston and valves? Any idea how much $? I guess I could ask him. Just curious. We have a couple we put nice walnut stocks on. Sure would be nice to upgrade a bit.

I got mine for $30. I ruined several o rings trying to install it so I deburred the tube good this time and I am getting Mil spec for better durability. I almost forgot to add that I bought the FTP from BBB back in March.

 

I bought a Flat top piston from Bart and  I am waiting on my o rings. Should be here next week.

and valve...?

Yes and the valve cap.

[Big Bore Bart]

   I don't have any valve caps at this time.     I do still have the tool to make more.     The thread that started it all.   Instructions for adapting a 13xx FTP to the 2100 are in the above thread.    The end results are here.   

[vigilandy]

Between getting home from work and sitting down for dinner I had time for one shot across the chrony... Oiled the felt piece,  10 pumps,  8.4gr AA pellet = 703 fps.  Bonus was that it took out a chunk of the rear of chrony on its way.  From 12 inches away.   Still works. 

[K.O.]

well at least it was not locked in the safe...

If you are not seating the pellets just past the port it can be worth 15-30 fps.

the plastic bolt has a hole in it and if you pull the probe forward carefully with needle nose pliers till it is open it will then seat the pellets just right.


at least that is how it is on the 2100b and be careful it is a magnet not steel so it breaks easy...