FX Crown .177 cal 600 mm Barrel

[ThomasT]

Hello everyone,

I have a FX Crown MK II .177 cal 600 mm Barrel that I have had pretty good luck shooting JSB 13.43 Monster Redesigned pellets but would like to try and tune it to shoot JSB Exact Heavy Diabolo 10.43. I am hoping that someone here on the Forum has the same rifle that they have already tuned to shoot the 10.43 to be very accurate. I would appreciate you sharing what, 1) Power Level, 2) Hammer Spring Setting and 3) Pressure you are using. I am not wanting any suggestions using a different length barrel, please.

EDIT: I forgot to say that I do have the new wheel that reads 0 to 23, so I need to know which wheel you have.

Thank you,
ThomasT

 

[airgunner1042]

My MK 11 was originally purchased new from FX as a .22 cal. 600mm bbl. Factory reg. set at 135, power wheel at 177/22 adjusted hammer spring to #5. shooting 18.13 JSB's lights out. After a long search, located an the AGN forum an original FX 600mm 177 barrel. Screwed it onto the receiver, changed the probe and mag. left the power setting alone, and the reg at 130. After some playing with the hammer spring, found the #4 setting resulted in the best accuracy shooting the 10.34's with a spread of 10 and SD of 4.4. @ avg.fps.913 @ 19.6 ft lbs. a little hot, but almost same hole at 25 yds. and 1/2" or better at 50 yds. { doing my part with good conditions }. This is an un-usual case as most of my buddies who have the same rifle, have the reg setting anywhere from 90 -110. Just lucked out with the outcome as noted. Now have best of both worlds. can shoot BR and FT under 20 lb max. limit. Guess I just lucked out. who knows, try it, might just work for you
Richard

 

[qball]

Without the new micro preload adjuster everyone's HS preload is different so there is no way to repeatably replicate a tune between guns. Best and easiest thing to do is simply reduce your hammer spring, you will likely need a newer style power wheel with more finer steps between PW settings.

 

[ThomasT]

My MK 11 was originally purchased new from FX as a .22 cal. 600mm bbl. Factory reg. set at 135, power wheel at 177/22 adjusted hammer spring to #5. shooting 18.13 JSB's lights out. After a long search, located an the AGN forum an original FX 600mm 177 barrel. Screwed it onto the receiver, changed the probe and mag. left the power setting alone, and the reg at 130. After some playing with the hammer spring, found the #4 setting resulted in the best accuracy shooting the 10.34's with a spread of 10 and SD of 4.4. @ avg.fps.913 @ 19.6 ft lbs. a little hot, but almost same hole at 25 yds. and 1/2" or better at 50 yds. { doing my part with good conditions }. This is an un-usual case as most of my buddies who have the same rifle, have the reg setting anywhere from 90 -110. Just lucked out with the outcome as noted. Now have best of both worlds. can shoot BR and FT under 20 lb max. limit. Guess I just lucked out. who knows, try it, might just work for you
Richard

Hello @airgunner1042 ,

Thanks for the information. I have tried the 130 pressure and with no luck, around 122 is the highest pressure that my gun likes for the 10.34. I truly believe my barrel is "odd" or a "one off", but I will try anything at least once .

Thanks again,
ThomasT

 

[tcarlson777]

@ThomasT - I could never get my 500mm .177 FX barrel to shoot the 10.34s nearly as good as the 13.43s. And it really hated the JSB 8.44s. I hope you can find a tune that your gun likes. The 10.34s have better overall consistency (of head size and weight), in my opinion. Sorting the 13.43s by head size and weight is relaxing, but kind of a pain.

 

[ThomasT]

@ThomasT - I could never get my 500mm .177 FX barrel to shoot the 10.34s nearly as good as the 13.43s. And it really hated the JSB 8.44s. I hope you can find a tune that your gun likes. The 10.34s have better overall consistency (of head size and weight), in my opinion. Sorting the 13.43s by head size and weight is relaxing, but kind of a pain.

Hello @tcarlson777

As you know Tom my gun shoots the 13.43 pretty good but I am hoping that I can tune it to shoot the 10.34's even better. Thanks for your help and have a great day,

ThomasT

 

[Humdinger]

Within the past month I bought my first Crown MKII in .177 with the 600mm barrel. I own an Impact MkII in .25 so I'm familiar with the hammer spring adjuster. I'm sure this Crown was factory set as a sub 12 ft. lb. .177. I must add that mine has the newer hammer spring wheel with 24 steps which is so much nicer to use than the older ABCDE/12345 that's on my Impact. As @TCarlson previously stated it is impossible to correlate settings between Crowns without the micro adjuster hammer spring setting capabilities of the Impact Mk3. I've had to tinker with my Crown to add about 4 complete turns of the hammer adjustment pin in order to bring the power up to FAC levels. Mine is currently set to 90 bar on the reg, 13 on the power wheel (halfway) and medium (.177/.22) on the transfer port. This is giving me 880 fps using CP 10.34s with one ragged hole at 25 yards and 1/2" groups at 50 yards in low wind. I really like the low reg pressure because I'm getting a lot more shots between fills without max settings on the hammer spring.

It would be nice if the Crown incorporated a micro adjustment setting like the Impacts. I don't know if it would fit in the Crown stock or if FX hasn't considered it since the Crown stock still must be removed in order to adjust the hammer pin extension.

 

[ThomasT]

Within the past month I bought my first Crown MKII in .177 with the 600mm barrel. I own an Impact MkII in .25 so I'm familiar with the hammer spring adjuster. I'm sure this Crown was factory set as a sub 12 ft. lb. .177. I must add that mine has the newer hammer spring wheel with 26 steps which is so much nicer to use than the older ABCDE/12345 that's on my Impact. As @TCarlson previously stated it is impossible to correlate settings between Crowns without the micro adjuster hammer spring setting capabilities of the Impact Mk3. I've had to tinker with my Crown to add about 4 complete turns of the hammer adjustment pin in order to bring the power up to FAC levels. Mine is currently set to 90 bar on the reg, 13 on the power wheel (halfway) and medium (.177/.22) on the transfer port. This is giving me 880 fps using CP 10.34s with one ragged hole at 25 yards and 1/2" groups at 50 yards in low wind. I really like the low reg pressure because I'm getting a lot more shots between fills without max settings on the hammer spring.

It would be nice if the Crown incorporated a micro adjustment setting like the Impacts. I don't know if it would fit in the Crown stock or if FX hasn't considered it since the Crown stock still must be removed in order to adjust the hammer pin extension.

Hello @Humdinger

Thanks for this information, boy it is so close to what I have just shot after I made some changes. See my post below.

Thanks again,
ThomasT

 

[ThomasT]

Hello everyone,

First off, thanks for all the help and sharing of information.

OK here is what I did: I reduced the Pressure from 120 down to 90, left the Power at Medium and set the HS at #22.

I had the scope already zeroed on the rifle so my first shot with the lower pressure dropped a little ( look at photo #1 ). I felt real good with this shot right on the windage line so I turned the elevation up and shot the second pellet, still on windage. Third shot dead center of the 10-Ring and I shot 6 more pellets. That is only .1315" center to center group. Then I shot the four outer 10-Rings with 5 pellets each.

At this point I am really pleased so I set up a 25-Yard MOA Target ( second photo ) and put all 30 shots within the MOA.

Too bad this next target does not count because it is the 30-Yard Challenge target which I shot at only 25 yards. However I am still very happy with the results with all but one pellet scoring an X.

At this point I will not make any changes until I can set up my Chronograph and keep a record of every change and the results.

Thanks again fellows for all the help,
ThomasT

 

[tcarlson777]

That is a fantastic .177 barrel! Never let it go.

 

[rsfrid]

Hello everyone,

First off, thanks for all the help and sharing of information.

OK here is what I did: I reduced the Pressure from 120 down to 90, left the Power at Medium and set the HS at #22.

I had the scope already zeroed on the rifle so my first shot with the lower pressure dropped a little ( look at photo #1 ). I felt real good with this shot right on the windage line so I turned the elevation up and shot the second pellet, still on windage. Third shot dead center of the 10-Ring and I shot 6 more pellets. That is only .1315" center to center group. Then I shot the four outer 10-Rings with 5 pellets each.

At this point I am really pleased so I set up a 25-Yard MOA Target ( second photo ) and put all 30 shots within the MOA.

Too bad this next target does not count because it is the 30-Yard Challenge target which I shot at only 25 yards. However I am still very happy with the results with all but one pellet scoring an X.

At this point I will not make any changes until I can set up my Chronograph and keep a record of every change and the results.

Thanks again fellows for all the help,
ThomasT

View attachment 330891View attachment 330892View attachment 330893

 

[ThomasT]

That is a fantastic .177 barrel! Never let it go.

Hello @tcarlson777

Boy this is quite a good surprise to get so close on my first attempt. You know how I like to "fiddle" with the settings but now I am "almost" afraid to touch this set up....note that I did say almost We have bad weather coming in tonight through Saturday so I will be shut down on my outside shooting.

Thanks
ThomasT

 

[ThomasT]

Hello @rsfrid

It is looking real good for shooting your One Hole Challenge once I fine tune this new set up . I am loving these 10.34's .

ThomasT

 

[rsfrid]

Hello @rsfrid

It is looking real good for shooting your One Hole Challenge once I fine tune this new set up . I am loving these 10.34's .

ThomasT

That's what I asked Tom to tune my Impact with. We shall see.

 

[ThomasT]

That's what I asked Tom to tune my Impact with. We shall see.

Hey again @rsfrid

I remember you telling me that and that made me go to work on the Crown. Somewhere here on the Forum I have a thread where I tested a LOT of pellets with the Crown and the 10.34 kept showing up in the "good" values and I just did not spend enough time with just the 10.34's. By the way, I shot all of those targets plus quite a few others on one tank of air and it is still above 115 bar. I like that

ThomasT

 

[fderry]

Without the new micro preload adjuster everyone's HS preload is different so there is no way to repeatably replicate a tune between guns. Best and easiest thing to do is simply reduce your hammer spring, you will likely need a newer style power wheel with more finer steps between PW settings.

qball
We can actually measure, with repeatability, the hammer preload on the Crown Mk2. E. Rowe has an older video showing how to do it with a caliper on an Impact. Once you get your best setting for a given pellet you measure the distance of the opening with the slider against the hammer adjuster wheel. The new micro adjuster on an Impact Mk3 is essentially doing the same thing without the need for a caliper. See attached picture.
Frank

 

[qball]

qball
We can actually measure, with repeatability, the hammer preload on the Crown Mk2. E. Rowe has an older video showing how to do it with a caliper on an Impact. Once you get your best setting for a given pellet you measure the distance of the opening with the slider against the hammer adjuster wheel. The new micro adjuster on an Impact Mk3 is essentially doing the same thing without the need for a caliper. See attached picture.
Frank

View attachment 330916

Yes you can measure it but everyone’s caliper and or measuring angle is slightly different, it’s quite small and even tiny bit 1/100 inch off speed if different. Then, regulator reading is a suggestion/range. If stars align then you can be close but unlikely if you apply my Crown’s FT settings you will get exact same speed as my gun or even within 15-20 fps. Then how do you replicate a gun’s harmonic from one gun to another? There is no adjustment for that. Even on the impact with micro adjuster preload is still a range, not everyone’s C1 is within 1/100th of an inch from the end of the Rod. Lighter the ammo and lower the power larger the margins of error or larger the effect of 1/100 inch difference in preload makes.

Moral of the story is learn to fine tune your gun because no settings can be replicated exactly, think of other people’s settings as good starting points.

 

[fderry]

Yes you can measure it but everyone’s caliper and or measuring angle is slightly different, it’s quite small and even tiny bit 1/100 inch off speed if different. Then, regulator reading is a suggestion/range. If stars align then you can be close but unlikely if you apply my Crown’s FT settings you will get exact same speed as my gun or even within 15-20 fps. Then how do you replicate a gun’s harmonic from one gun to another? There is no adjustment for that. Even on the impact with micro adjuster preload is still a range, not everyone’s C1 is within 1/100th of an inch from the end of the Rod. Lighter the ammo and lower the power larger the margins of error or larger the effect of 1/100 inch difference in preload makes.

Moral of the story is learn to fine tune your gun because no settings can be replicated exactly, think of other people’s settings as good starting points.

qball
I agree that any measurement will only apply to the gun they are made on and depend on measuring accuracy. The issue I had with your initial comment is that the Crown micro hammer adjustment wasn't as measurable as the new micro preload adjuster. Both are valid but may be misleading for another person's airgun as you have just pointed out.
The advantage of sharing measurement data is that it may get somebody else into the ball park for the same configuration thus reducing the time and effort in tuning their airgun. The key is not to take the information as an absolute.
I have a problem with determining a good regulator starting point therefore I will ask for help. You provided me with a good starting point for my new Crown/pellet combination. I took that as a good starting point and got to a good initial tune faster than me just guessing at a starting pressure (thank you).
Frank

 

[ThomasT]

qball
I agree that any measurement will only apply to the gun they are made on and depend on measuring accuracy. The issue I had with your initial comment is that the Crown micro hammer adjustment wasn't as measurable as the new micro preload adjuster. Both are valid but may be misleading for another person's airgun as you have just pointed out.
The advantage of sharing measurement data is that it may get somebody else into the ball park for the same configuration thus reducing the time and effort in tuning their airgun. The key is not to take the information as an absolute.
I have a problem with determining a good regulator starting point therefore I will ask for help. You provided me with a good starting point for my new Crown/pellet combination. I took that as a good starting point and got to a good initial tune faster than me just guessing at a starting pressure (thank you).
Frank

Hello @fderry

Frank you understand my interest in asking for other Forum Members to share their settings on a "like gun", and in my case the FX Crown MK II .177 cal. What I was able to learn from the other members along with some of my past testing gave me a great starting point. As you can see from the results of this information I got pretty close on my first attempt. I truly appreciate any and all information that a Forum Member is so willing to share, I try to share my information as best that I can. Thank you Frank.

ThomasT

 

[cavedweller]

Hello everyone,

I have a FX Crown MK II .177 cal 600 mm Barrel that I have had pretty good luck shooting JSB 13.43 Monster Redesigned pellets but would like to try and tune it to shoot JSB Exact Heavy Diabolo 10.43. I am hoping that someone here on the Forum has the same rifle that they have already tuned to shoot the 10.43 to be very accurate. I would appreciate you sharing what, 1) Power Level, 2) Hammer Spring Setting and 3) Pressure you are using. I am not wanting any suggestions using a different length barrel, please.

EDIT: I forgot to say that I do have the new wheel that reads 0 to 23, so I need to know which wheel you have.

Thank you,
ThomasT

Contact @dougar he turned mine into a laser! I’m using 10.43 jsb to stay under 20 fpe