Crosman 2300KT – Is this normal??

[Alex70]

I started this hobby shooting springers a little over a year ago and decided to try CO2.
I ordered a Crosman 2300kt (4.5mm) from the custom shop and went out to try it today.  I encountered a few unexpected situations and was hoping to get some advice/confirmation from you.  As said, I am new to CO2, so excuse any silly questions:

1. The cap doesn’t screw all the way in with the CO2 tank inside.  Is this normal?  I tightened the cap, but didn’t want to force it.
2. I got 48 shots out of the tank.  I was expecting around 60. Is less than 50 shots acceptable?
3. This one concerns me in particular:  I ran the 48 shots through the Chrony and each one of them was invariably slower than the previous one.  Shot #1 was 560 fps and shot #48 was 138fps.  Actually, the last pellet is still in the barrel because the gun had no power to shot it out.  Is this normal??!!

I used Crosman Premier Hollow points (7.9g) and the temperature was 66°F

Many thanks!

[DavidS]

I started this hobby shooting springers a little over a year ago and decided to try CO2.
I ordered a Crosman 2300kt (4.5mm) from the custom shop and went out to try it today.  I encountered a few unexpected situations and was hoping to get some advice/confirmation from you.  As said, I am new to CO2, so excuse any silly questions:

1. The cap doesn’t screw all the way in with the CO2 tank inside.  Is this normal?  I tightened the cap, but didn’t want to force it.
2. I got 48 shots out of the tank.  I was expecting around 60. Is less than 50 shots acceptable?
3. This one concerns me in particular:  I ran the 48 shots through the Chrony and each one of them was invariably slower than the previous one.  Shot #1 was 560 fps and shot #48 was 138fps.  Actually, the last pellet is still in the barrel because the gun had no power to shot it out.  Is this normal??!!

I used Crosman Premier Hollow points (7.9g) and the temperature was 66°F

Many thanks!

1: Most of the 2240's I have had have had the same trouble, so I think it is normal.
2: I am surprised you got that many shots.
3:  2 part answer: A: Shooting to fast (with out a good long pause between shots) reduces the temperature of the CO2 powerlet thus reducing power. B: Once most of the liquid CO2 is gone the power drops off the bottom for the last 10 to 15 shots, I would only count the shots that you get consistent power with a full minute between shots.

Hope that helps.

[AgentWD40_FL]

I also have a 2300KT CCS ... but your questions are relevant to any Co2 gun.

1. The cap doesn’t screw all the way in with the CO2 tank inside.  Is this normal?  I tightened the cap, but didn’t want to force it.

You should only screw the cap in finger tight. Don't use any tools. Your not trying to pierce the powerlet with the cap. To pierce the powerlet, cock the gun, point in a safe direction (unloaded!) and pull the trigger. I have to do this twice.

2. I got 48 shots out of the tank.  I was expecting around 60. Is less than 50 shots acceptable?

That shot count is about right, but only 40 of those are usable.  Maybe on a really warm day, the shot count will increase.  Theres a couple things you can do to raise the shot count .... but it will be at the expense of FPS.

3. This one concerns me in particular:  I ran the 48 shots through the Chrony and each one of them was invariably slower than the previous one.  Shot #1 was 560 fps and shot #48 was 138fps.  Actually, the last pellet is still in the barrel because the gun had no power to shot it out.  Is this normal??!!

Using a chrony, you have to make every shot equal to the last.  As previously said, you should wait 1 minute between shots to allow the powerlet to come back up to temperature ---> max power available. Record your shot strings and if you can imagine a graphed curve of the overall powerlet .... you'll notice a point at which the power really starts to fall.  This is the break point of 'usable' shots.  On all of my Co2 pistols, as soon as I notice the drastic dropoff, a) store the gun away (yes, stored with some Co2 pressure in the gun); b) dry fire the gun once or twice, until I can unscrew the cap with my fingers, and install a new powerlet to continue the session at peak performance

You should also put a drop of PellGun lube on every other powerlet, and every once in awhile put a drop on the probe o-ring,

[AgentWD40_FL]

By the way .... nice shooter you have there.  I havent done anything to mine except add a scope and adjust the trigger spring to my liking.  Accurate, consistent and a joy to shoot.

[avator]

+1 on everything said. We have 2 2240 converted to .177 bugouts and 1 2240 as a stock .22 pistol w/steel breech. I don't even waist pellets on the last 6 or so shots. I just dry fire it out and put in a new cart. I think I get around 35 good shots per cart. I just got a '57 180 and ordered a Heritage 2260. I expect virtually the same results from these.

[Alex70]

Great information.  Thanks much.

Now abusing of your patience a couple more novice questions:

1.  So, if I allow enough time between shots, will I get a good number of consistent ones?.  Larry talks about a curve, so I am more inclined to think that it is the nature of CO2 to deliver a little less power with each shot as the tank empties.  This I guess turns into a different POI for each shot.  How then can one adjust the sights under such conditions?
2.  My guess is that you learn this just by experience, but are there any signs of that “break point” in power, other than your pellets start hitting really low?

[AgentWD40_FL]

If your using a chrony .... wait the full minute between shots to get accurate FPS numbers.  However when paper punching or tin can plinking, I only wait as long as it takes to load another pellet in my single shot pistols.  POI /accuracy is going to stay constant through the 'usable shots'. 

[ac12]

co2 is interesting compared to compressed air.
While there is liquid co2 in the tank, the pressure is constant, about 800 psi.  The co2 evaporates to maintain that pressure.  So co2 is actually better than an unregulated CA/PCP gun, for constant pressure.  This constant pressure = consistent velocity.

The thing is you have to maintain constant temperature of the gun.  As the temp of the gun goes down, the pressure drops, and so does the velocity.   When you fire, the released co2 causes a temp drop in the gun.  This is why you have to wait between shots for the gun to warm up again. 

By the same token, when the ambient temp is higher, you will get more velocity out of the gun.  But when it gets too hot, the gun can "lock up" and fail to fire, due to the excess pressure of the co2.

[Alex70]

Quite interesting.  I appreciate your help.

It is indeed a nice shooter.  I did my research before deciding on this model and read about the reputation of the poor trigger that the 22XX series have.  But I liked the gun a lot and decided to acquire it and just do a major trigger job.  To my surprise, it is actually quite good.  I just adjusted it to the lightest pull with the mechanism it comes with, and it feels really very soft.  I mean, it’s not a match grade trigger of course, but much better than expected.  I don’t know if Crosman is improving that part all together, or is it only for the custom models ¿?

One thing that does need fixing:  I ordered the MIM open rear sight and a muzzle break with a pole as front sight.  Well, the combination of both hits too high even with the rear sight adjusted all the way down…  I am thinking about ways to slightly increase the pole length for a lower aim

Thanks again

[kj]

the colder it is the more you would have to wait to keep consistant. i usually set my co2 guns up to give me a even consistancy @ 70 degrees. at 70 i can shoot as fast as i want with no variation.  at lower temps not as consistant. however they can be tuned for cooler temps. you might get a whoosh of co2  near the end of the cartridge as there might not be enough pressure to close the valve. in 80* temps keep your gun out of the sun. like previously mentioned , the valve can lock if the co3 cart gets too warm. a heavier spring, or more pre-load can over-come this.

bob, rsterne, has posted alot of excellent info on this topic. perhaps you can find some of them on search. should be a sticky.

peace
kj

[dwk54rak]

I have 2 2300t one in 22 and one in .177 They both get about 40 shots per powerlet. I just count out 40 rounds and change when I get to that limit

[Alex70]

Just as a follow up on this, I want to thank you for your suggestions - I followed your advise this weekend and got great results! Here are the chrony numbers:

Low: 528.6
High: 541.4
Average: 535.9
Extreme spread: 12.84
Standard deviation:  4.35

I made 40 shots, but seems like the tank could deliver a few more. I will try 45 next time.

Thanks again!