FX Crown .177 accuracy

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Arvid

Arvid

Member
Jul 24, 2018
47
3
Trøndelag, Norway
Hi!

I`m struggling to get any kind of accuracy out of my new FX Crown .177. I have tested various FPS, reg.settings and hammer spring tension. In addition to that I have testet a lot of different pellets. Nothing really works. Not even at 20 meters where it should shoot pellets on top of each other. For a while i tought that it could be someting wrong with my scope, so I tried two other scopes and also tested those scopes on my AA S510. I will also try my brand new scope (Vortex Viper PST GEN II 5-25x50). But so far I have concluded that the scopes are OK. 

I will upload some pictures of groupings later. But for now I`ll post an example of shot string from some of the testing I have done. Did not test for accuracy at this time since I have to by another type of chrono for that. And yes, it is running hot for these light pellets. I used them only for to test the reg.

I am going to change to .22 or .25, but i would like to get the gun to work also in cal .177. On this level and hot price i should do better. 

Barrel is cleaned and inspected for burrs. No pellet clipping. Tried different positions with the shroud. I can sometimes clearly see pellets hitting the target from different directiones. This occurs with all different pellets.


Pellet: H&N Sniper Medium 8,49gr. (Cheap pellets used for this chrono test only)

Reg.: 95 bar

HS: 20mm

Fill: 250-220 bar

Shots: 21

993

964

986

961

964

1000

961

990

972

993

982

990

990

990

990

993

990

986

986

982

982


Pellet: H&N Sniper Medium 8,49gr. 

Reg.: 95 bar

HS: 20mm

Fill: 220-200 bar

Shots: 21

972

986

986

972

972

972

972

972

972

972

972

972

972

972

972

972

972

972

972

972

972


Pellet: H&N Sniper Medium 8,49gr. 

Reg.: 95 bar

HS: 19mm

Fill: 200-180 bar

Shots: 21

All 21 shots at 972 fps.


Pellet: H&N Sniper Medium 8,49gr. 

Reg.: 100 bar

HS: 19mm

Fill: 180-165 bar

Shots: 21

1000

1004

1000

1000

1000

1004

1000

1000

1000

1000

1000

993

1000

1000

1004

993

1000

1000

1000

1000

1000


Pellet: H&N Sniper Medium 8,49gr. 

Reg.: 110 bar

HS: 19mm

Fill: 165-148 bar

Shots: 21

1029

1029

1029

1029

1022

1022

1036

1047

1036

1036

1047

1036

1040

1040

1040

1040

1029

1036

1047

1040

1040


 
Nope, love it! looks handling shot count everything, except that I have no confidence in it whatsoever! I have .177 and .22 guns, ordered spare barrels and all do the same!

They shoot fantastic groups on minute and the next they dont! (I have owned 3 Crowns from new).

I chrono'd the other night and the Crown properly bedded in and messed about with, hammer spring and reg pressure struggles to get 20FPS EX spread!

So I bought my third Redwold and shot it straight out of the box, ES 3FPS and a 25 shot group measuring .3.

Go figure! I am having a custom Walther barrel fitted this week and will compare like for like, if I get no joy the whole world will know about it LOL!
 
Upvote 0
Hi,

Please try and get some JSB 10.34 and send then at about 890-920 FPS. I haven't ever used 8.44 but I think the recommended velocity is around 960 fps for that pellet, but I haven't seen anyone get great results with the 8.44 grain. I really like the JSB brand in the FX guns, I have tried a few of the H&N pellets in different calibres but have found them not as accurate generally.

The first string you show indicates a reg and hammer spring imbalance, the gun seems to settle after the first mag so at least we know that the potential for a good string is there, Sorry I don't have a .177 crown pellet probe yet otherwise I could give you a few settings to duplicate. My impact is at 105 bar and shoots the 10.34 at 910fps very well, maybe not hole in hole at 20 meters but they all touch each other in a 15mm cluster, is your transfer port wheel on .22/.177 or on min?

I am watching this thread with interest...
 
Upvote 0
my rapid air weapons bm500 177 came from the factory doing 915 fps jas 10.3s... I detuned to 880 fps and the accuracy got even better.. bench rest quality.

30 yards groups of 3 too 4 mm ctc all day long out doors

before detuning the groups were 1 mm bigger on average...

as of now I can easly get 10 shot groups of 12 mm ctc no problem out doors .. consisantly
 
Upvote 0
I agree with the above posters... your velocity is far to high to hold accuracy... at those speeds those little .177 pellets are spiraling badly... drop your speed down to 880-900 and you’ll see your groups tighten up a TON! 



The concerns about the .177 were mainly in the old FX smooth twist... the smaller pellets didn’t catch the “rifling” good enough... the new X Barrels shoot them MUCH better... 



Good Luck!

Sharkman


 
Upvote 0
Hi and thank you for replies.

I know its to hot for those light pellets. Used them only to test if the reg is holding up.

I would prefer to get accuracy with JSB 10.34, 13.40 or 16,20 and have tried those in the range 860-920.

The transfer port is set to .22/.177.

And yes, I could just buy or return for another airgun. But per now I have this and would like it to work as advertised.

thor47 recommended to try another pellet size (4,53mm) but I have not got hold of any here in Norway.

Maybe just go for .22 og .25 right away. 

I checked if the pellets are catching the rifling and it seems to be ok. 

Anyone who hav tried to remove the o-ring around the barrel with any luck? Should not be the case, but who knows..
 
Upvote 0
i also have a crown in 177 with the same problem. accuracy is terrible. it is now back at FX USA for the second time. they have had it more than i have. very disappointed to say the least. as others have said, use the jsbs either the 8gr or the 10gr and get your speed around 880. i'm wondering (having had 12 fx guns) if the smooth twist is a better option in 177 than the X barrel. good luck with this. keep us updated.
 
Upvote 0
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