I am hoping that that someone can help me find a solution for my FX Crown Mk11 . I can not get pellets speed much over 700 FPS even with reg up to 160 and settings for high power I recently changed the reg and it was Ok for a short while . It not breech seals because I tried it with 2 different barrels .Any help will be appreciated Thanks
FX cant get velocity from FX Crown
- Thread starter Sharp Pog
- Start date
Your reg pressure seems correct for the Crowns...maybe like said above about your HS or maybe it needs more pre-load? Or maybe the HS is broken?
Upvote 0
I went through a similar rodeo in the last couple of months. It sounds to me like your reg is high and the hammer does not have enough energy to open the vale fully. Increasing reg pressure has to be paired with increased hammer energy. The Crown's method of increasing hammer spring tension is, for me, counter intuitive. I only understood it after I had the macro and micro adjusters out a couple of times and studied them. Also, my gun is a .22 and they do not come with a hammer weight installed. I think that this, in my case, sets an upper power limit that is not mentioned in the manual or often in the threads.
Back off on the reg and see if the power starts to go up. Then work your way back up until you get what you want. It worked for me.
Ron
Back off on the reg and see if the power starts to go up. Then work your way back up until you get what you want. It worked for me.
Ron
Upvote 0
On a Vulcan I once had a problem with fps because the hammer was not reaching properly the valve.
Reassemble it and the problem was fixed.
Reassemble it and the problem was fixed.
Upvote 0
I shoot a Crown .25 caliber. My regulator is set at around 135bar. It shoots 25.4gr pellets at 920FPS and I can get around 80 shots in a single fill before topping-off.
This is using the "C" setting on the rear dial and of course the 25-30 setting on the front dial. It can go faster if I choose, but 920ish is a good speed for good accuracy.
That said, I believe that your regulator is set too high. The suggestion above to bring it down is a solid one.
mike
This is using the "C" setting on the rear dial and of course the 25-30 setting on the front dial. It can go faster if I choose, but 920ish is a good speed for good accuracy.
That said, I believe that your regulator is set too high. The suggestion above to bring it down is a solid one.
mike
Upvote 0
Reg seems correct?
Realy?
Reed the manual before posting things like this
Sorry but .....let i go dingens ,let it go
Upvote 0
You shouldn’t need 160 on the reg. Agree you should check your hammer. Don’t forget that you may need to remove the stock to get the hammer spring low/high enough if someone else has adjusted it there. The hammer wheel is just part of the adjustment range. You can adjust it more by removing the stock if the hammer wheel isn’t doing enough.
Upvote 0
It should be an equilibrium among pressure on the regulator and strength of the hammer.
Too much pressure on regulator, valve do not open property at the hit of the hammer.
Too much hammer force on hammer with low regulator, waist of air.
Too much pressure on regulator, valve do not open property at the hit of the hammer.
Too much hammer force on hammer with low regulator, waist of air.
Upvote 0
In some rifles (like Delta Wolf), If the probe that pushes the pellet has the hole looking upwards in stead of downwards, the air do not flow adequately to the barrel and fps is low.
Upvote 0
Your reg pressure is way to high causing the hammer to not be able to fully open the valve. You're at partial valve lock. Lower reg to 100 bar and work up from there.
Upvote 0
I actually work on my friends Crown in .22..... tested the reg pressure @ 160bar had a friend who works for AirTanksforSale re-test it, yeah, 160bar factory was normal because of the small plenum and he works on plenty of FX guns and said that was how they come from FX....sorry but the post is correct.....friends is a 380mm barrel.
Last edited:
Upvote 0
No. The old crown even states in the manual that 150 is the max.
From the manual: NOTICE – NEVER adjust the regulator above 150 BAR as damage to the system may occur and will void your warranty!
I don't see any pellet weight or caliber listed but on my .22 (albeit the mk2 model) the regulator sits at 110 for 880fps on the JSB RS with the spring set to lowest. Pushing it up to the middle tension gets me to 880 with Exact Jumbos.
160 is too much. He should start at 100 - 130 and go from there. I would go to 100 and balance the valve first and then see how fast I want to go with my pellets.
Upvote 0
You are correct in what the manual says for an Mkii but my friends Crown MKi was factory set to 160bar maybe because of such a short barrel length. That's why I took it to Joe's shop because I live 1 mile from him after I tested it. He got the same readings and works on many FX rifles and said that is normal for such a small plenum 380mm barrel set up to shoot 18gr @ 880fps because of shot count and the distance he shoots it, my friend wanted more FPS but I talked him out of that, unusually high reg set point from my perspective but it has had zero issues since 2019 and it's quiet and accurate. Mkii' do have larger plenums friends is an mki.
Last edited:
Upvote 0
Some things to check.
1) is your reg gage correct. 160bar is max for AMP reg's normally.
2) did you try backing the reg down and working up with the hammer spring?
4) the mk2 has a ~54cc plenum, so should hit 50+fpe with correct weight pellets and barrel length without problems.
I thought the OP was talking mk2?
My two Mk2 Crowns have not needed that kind of reg pressure and I wouldn't call 54cc small. It is true short barrels like higher reg pressures but there is a reward/ benefit cutoff where you just need more barrel.
My 177 Mk2 is shooting 10gr pellets @ 880 fps with a 100 bar reg
1) is your reg gage correct. 160bar is max for AMP reg's normally.
2) did you try backing the reg down and working up with the hammer spring?
4) the mk2 has a ~54cc plenum, so should hit 50+fpe with correct weight pellets and barrel length without problems.
I thought the OP was talking mk2?
My two Mk2 Crowns have not needed that kind of reg pressure and I wouldn't call 54cc small. It is true short barrels like higher reg pressures but there is a reward/ benefit cutoff where you just need more barrel.
My 177 Mk2 is shooting 10gr pellets @ 880 fps with a 100 bar reg
Upvote 0
Hi,
An interesting string of comments set off by your question. But to really help you out it would be extremely useful for you to tell us something about your rifle and what pellets you are looking to shoot at what range. There is an extensive knowledge base on Crowns in this forum as many of us love the rifle and often have more than one.
It might also help if you let us know of your comfort level on working on the rifle. The Crowns are fairly straight forward mechanically and are very well machined without too many o-rings. There is quite a bit that can be upgraded/change (not as much as on an Impact) to make the rifle more suited to a shooter specific desire.
Cheers,
Greg
Upvote 0
Hi Bob,
I don’t believe the Crown Mk2 has a 54cc plenum volume.
The Crown is a “medium powered” FX platform - somewhat due to its relatively small plenum size. I believe the Crown Mk1 was about 28cc plenum and the Crown Mk2 was touted as “25% larger” by FX marketing - which equates to about a 35cc plenum.
I’d agree with the advice given by numerous AGN posters - the 160bar reg pressure is too high - likely resulting in partial valve lock (not enough hammer strike to fully open valve) and the resultant low fps.
To the original poster - pull out your hammer adjuster and measure it with calipers.
Here is a couple recent settings I’ve used on my 3 Crown Mk2s - see hammer adjuster preload measurements below.
-Ed
Upvote 0
My FX crown MK2 reg is 95bar micro wheel on 3, shooting JSB 18.1 avg 923fps for 100 shots or better w/700mm barrel. What barrel are you shooting needs to be figured in also.
Upvote 0
EPG, You may well be right FX has been rather cagy about its size. I read somewhere they admitted to 54cc on the mk2 but I don't know if it's true. The idea gains some credence from looking at the different models and their max power ratings on the FX site. They seem to follow the 1cc/fpe give or take but that's highly speculative with different bbl length, calibers etc.
we do need more info
we do need more info
Upvote 0