N/A Crosman Icon - how to flatten the shot string

I received and shot my Crosman Icon in .177/.22 for the past few days.

I am getting a 50-60 FPS spread in .177 or .22 over 3 magazines, not matter the adjustments of the hammer spring and start/end air pressure.

Has anybody done any concrete mods on the Crosman Icon to flatten the shot string?
I am familiar with the options available to flatten/improve a shot string (SSG, TSG, BStaley, etc) but I need something concrete which works.
If you did, please provide details.

I believe that the Beeman Chief 2, 1357/1358, 2027 and other variants are very similar to the Icon, trigger, hammer spring, magazines, etc
Maybe someone has improved the shot string for the Beeman PCPs above?
 
I really like the 2 Crosman Icon .177 and .22.
Solid build, very accurate, only added a barrel band and moderator.

I still think that the shot string can be made flatter.
For instance the Beeman 1358 gives me 40 shots with the same 50-60 FPS spread.
That was a great sale on them.

I think it’s a solid gun.
It’s fps spread seems pretty typical for a unreged small tanked pcp.

I’m sure it can be tweaked
 
That was a great sale on them.

I think it’s a solid gun.
It’s fps spread seems pretty typical for a unreged small tanked pcp.

I’m sure it can be tweaked
Yes, the spread is about average for a PCP with that air tank size (135cc).

But, for instance the Kral NP03 (180cc air tank) gives me 50 shots at a spread of less than 40 FPS.
That is because I can use the transfer port adjuster/power adjuster to get that spread.
An unregulated PCP would really benefit from a transfer port adjuster.
 
You get that many shots from your NP. In what caliber ?
I don’t mess with my transfer port on my NP I get about 35 shots wide open in .17
I have a Kral NP3 in .177 and one in .22.
My goal was 4 magazines of shots.

I replaced the hammer spring with a stronger one so I can slightly overfill.
My shot strings start around 250 bar (instead the max 200 bar) and end around 150 bar.
I reduced the power using the transfer port until I found the balance I wanted.

The Kral NP3 has a burst disk which has burst on mine.
I replaced the burst disk with a round piece cut from a metal pellet tin.
I have been shooting them like this for 2 years without issues.
I fill them up to about 250 bar and shoot them in the next few hours, always the same day.
 
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I grabbed an Icon during that big sale like many folks did. Haven't had too much time to shoot it yet but I like it. Think I'll put a reg in eventually and tune to 20fp for HFT. Try other mods. Lap the barrel and perhaps recrown.
Figure that at $130 I can't lose for learning alone. If I ruin the gun I'm only out $130. If I succeed I have an HFT gun for the retail price of the icon or less. :cool:
 
I grabbed an Icon during that big sale like many folks did. Haven't had too much time to shoot it yet but I like it. Think I'll put a reg in eventually and tune to 20fp for HFT. Try other mods. Lap the barrel and perhaps recrown.
Figure that at $130 I can't lose for learning alone. If I ruin the gun I'm only out $130. If I succeed I have an HFT gun for the retail price of the icon or less. :cool:
My Icons are accurate already and did not even clean the barrels.
I am not sure how a barrel recrown could improve the shot string.
 
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