Increasing shot count in the 2240

[Poorman Plinker]

Three different ways to increase shot count in the 2240 as posted in the Crosman PoormanPlinker Mods 2240/1377 facebook group:

You can TRIPLE YOUR SHOT COUNT if you are willing to DECREASE VELOCITY BY ONE THIRD. A test of my 2240 recently produced around an average of 426 fps for about 40 shots.

[agninja]

Interesting. I'm wondering if a longer barrel would help with that coefficient as well. For instance, the short barreled 2240 is a gas hog and is inefficient. If you have a longer barrel you get more power...or you get the same power with less gas, depending on how you look at it.

So basically what I'm saying is how would those mods look efficiency-wise on a short and long barrel? Could you get the same amount of shots but with a little more fps behind them if you had a long barrel?

[BillK]

For $10 or so you can have all of the adjustability at your finger tips. (Mellon Air)

[Poorman Plinker]

Mr. Agninja, those are very fair questions. Would barrel length effect efficiency of a gun with the above mods? And Would a longer barrel produce higher velocity than a 2240 barrel as used with the above mods?
Just guessing... I think that one would still get 120 shots with the vinyl cap ($0.03) in a 24" barrel, but I would be concerned that the 326 fps at 7" would be reduced by drag over the longer length. The valve spring shim and spring clip methods I would think could be tuned to produce greater efficiency in the 24' barrel than in the 7' barrel. However that is my next test (barrel length and pellet velocity on a factory valve in co2).
The gas use seems to be controlled by the valve, striker, tp, pellet, spring combinations and not barrel length. If barrel length has a positive effect on the factory settings is something I have read many different views on. Common belief is that longer barrels create more velocity from the same amount of gas.
Mr. K, I do like power adjusters, but unless you change the striker spring, valve, or other components in some way you can only go from factory efficiency to less efficiency ie: more gas use and not less. Not only will cranking down a power adjuster reduce shot count, it may also reduce the averaged energy of the total shot count.

[BillK]

Crosman provides a softer blue colored spring with their RPAs.  I think it's because their RPAs have so little adjustment.
The Mellon adjuster has a great deal of adjustability.  You can even make it soft enough to not pierce the powerlet.
  I think you assumed that I was referring to cranking down on the spring and not turning it out for less power. 
I have a 2240 valve w/spacer & RPA on a 1760 that shoots 500+/- fps for appx 60 shots.  Since most of my shooting is at paper my RPAs are turned out not in.  I like the 500 fps area because it puts such nice clean holes in the paper.

[arkmaker †]

From what I have experienced with the 22xx platform is that a longer barrel equal more fps with no loss in shot count. The longer barrel give the gas time to work increasing speed behind the pellet.


I know this is a .177 caliber barrel, but the principle remains the same. This was with the valve and no valve spacer and a stock 2240 spring. No other changes. I was getting about 520 fps with a stock crosman 7.5" barrel (in .177). When I put on the 10" LW .177 barrel it jumped up 20 fps. Bigger gains have been noted up to 24. I think I was just under 700 fps with the transformer 2 which had a 24" barrel and bulk filled with 88 gram carts.


This same 1740 is now tamed down to around 450 fps for a good 50 shots and I can stretch it out for another 5 - 8 if I can deal with not knowing when the POI will drop on me :-) The 2240 spring is cut in half and a PA installed backed off a few turns from a stock setting and there is a reducer in the valve.
Sometimes takes 3-4 hits to pierce the carts, but once it does tha shot curve remains within 15 fps. Opening up or restricting the TP can change things up a bit as well, but I try to stay away from that when at all possible.

[beerhippy]

That is something I need to try.  Shoot a whole cartridge across the chrono recording the velocities. I never seem to have trouble noticing when the cartridge is running down  but I've never counted the shots either.  This is a thought provoking post.

[arkmaker †]

Yep, and if you are shooting targets or for that matter hunting, you will know when to change out the cart 2-3 shots "before" the POI drops off the charts 


Just because the velocity drops doesn't necessarily mean that you will have a drop in Point of Impact, but at some point it will drop....and usually 1-1/2" to 2" quickly and progressively. At least that is what I have been seeing. The Challenger really just drops in FPS but stays on target for ever, but then bam, you see a substantial drop. If hunting, velocity may well be a factor so knowing what that magic cut off point for you is may just well save you from having to track a wounded animal?

[Poorman Plinker]

In all fairness Mr. K I do not own a Mellon adjuster just 2 different Crosman adjusters. The Crosman adjusters stop at the factory setting when backed off and (as we both suggested) you need to change the spring to reduce the gas use/striker speed. 
Thanks for the inspiration Arkmaker. You are absolutely correct about fps and poi. In the above tests I stopped shot count when (first) the shot dropped below 300 fps for 2 consecutive shots. In the second and third tests I stopped the shot count when fps fell below 400 fps for two consecutive shots.
It would be more meaningful to stop the shot count when the velocity spread reaches the point that it moves the poi... But, what velocity spread is that? And then for the hunters... velocity spread at range (do not even want to do that math ha ha ha).
PS Mr. Arkmaker, I like the 1740 tune you described... Did you buy the 1740 complete or build it from parts? 

[arkmaker †]

Ahh, the 1740! My pride and joy. Can always count on it making me smile, because when I miss with it, I know it is me and not the pistol 


It actually started as a brand new 2240. I built it for my father and added a steel breech, LDC, Scope and did the barrel and trigger work. Over time, I added the 1701P trigger frame for him and he picked out the RB Walnut Grips, which I added the Crosman Logo pin to. When he passed, I swapped the steel breech for the Anthony R. aluminum breech and Mellon PA. Then a very good gent on this forum pretty much gave me a 10" LW .177 barrel. I then added a valve reducer and tweaked the springs to where it is now. I do believe it is shooting in the 480 fps range for 40-45 shots before a drop in POI. Don't hold me to those numbers. I has been a while since I ran it over the chrony. It is my bench rest pistol.


Just today, I received the new 1740 tube from David (Davio). So tonight I will swap out the old 2240 tube and put the PA back on. That will be the last mod I make to it (unless I ever get the breech black anodized). It will officially be a knockoff 1740, but a really good knockoff 


Bet you are sorry you asked now 
Rich

[GreyCoyote]

That is a work of art and worth far more than every word you used to describe it!    It sounds like a real shooter, too. 

[Noah]

That is a nice set-up. You know me, numbers? 

[Poorman Plinker]

Not sorry at all Rich... Love the gun  Thanks for the pic and the description. I am probably going to stick to the 10' barrel myself just due to the results in .22. I am going to have to take out the chrono and set up a target and attempt to determine what range of fps change the poi??? Seems like that will be particular to each gun/pellet/valve/barrel/etc variable. 

[BillK]

Not sorry at all Rich... Love the gun  Thanks for the pic and the description. I am probably going to stick to the 10' barrel myself just due to the results in .22. I am going to have to take out the chrono and set up a target and attempt to determine what range of fps change the poi??? Seems like that will be particular to each gun/pellet/valve/barrel/etc variable. 

Ya also gotta make sure it makes nice, crisp, clean, well defined holes in the target.

[arkmaker †]

That is a nice set-up. You know me, numbers? 

Now that I have the 1740 tube on and the PA/spring back, I will try to run a couple of carts worth over the chrony. I have the next couple of days off and I do need to do some shooting!! I'll post a new thread in the General Airgun section when I'm done.


Sorry Plinker for going off topic in your thread.