Hi guys. I have a UK restricted crown. I have changed the 22 barrel for .25. And main spring for fac. Changed valve spring for fac international version Cranked up regulator to 150 bar. Tightened spring tensioning screw to full and have power wheel on max the front wheel that turns from 177. .22. .25. .30. Low. I have drilled out the hole on .25. I have drilled out the barrel hole to max but still I can only get 25 ft lb and 680 FPS. What else should I do? I need to get up to 900fps would a huma regulator get me there ? Do I drill out the regulator port to let more air through?? Anybody please help I am desperate.
Fx crown
- Thread starter Karly64
- Start date
Correct me if I am wrong but isn't that illegal in the UK? I thought there was a 12 FP limit.
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It would be illegal if I didn’t have an fac licence lol I could have bought an fac version but thought it would be more fun and rewarding actually working on it myself
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Hammer weight might be the additional difference between FAC and Non-FAC versions. I tried doing the opposite and get a Wildcat down to 11.5 FPE and the hammer is the only thing that FX USA mentioned that's different than you mention. For me it was a smaller TP, lighter spring (hammer and valve) reg adjustment and a lighter hammer... You are doing the reverse. You might not be getting the gains from the higher reg pressure and heavier spring. I'm not a fan of hitting the valve harder but that 'MIGHT' be a stumbling point. I don't know who you might call in the UK but think FX USA techs might be able to help. If you call around, I'd also ask if the valve is the same between the versions. No point in breaking the valve/stem by hitting it with a heavier hammer.
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Did you try to increase both hammerspring tension and regpressure in steps, rather then go all the way? Your gauge might be wrong, and you have to much regpressure?
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Thanks for the information regarding the hammer. It is a fair point I did look around to see if there was a heavier hammer but couldn’t see one. Maybe it’s a special order. Il have to re look
the reg pressure idea is a fair one too I did think tonight maybe I should try dropping the pressure a bit but when you here all these guys with 50- 60 ft lb and regs set at 150 bar. It’s strange I have got it to 25ft lb but the FPS is very poor
the reg pressure idea is a fair one too I did think tonight maybe I should try dropping the pressure a bit but when you here all these guys with 50- 60 ft lb and regs set at 150 bar. It’s strange I have got it to 25ft lb but the FPS is very poor
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I just tightened the hammer spring then adjust the reg pressure. I do notice though as I shoot a few magazines and bottle pressure drops. So does reg pressure
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Thanks for that information jcd it’s very helpful
i understand that it’s not .30 so 70ft lbs and 1000fps is probably not achievable but at leat hi 700’s to bottom 800 FPS would be nice
i understand that it’s not .30 so 70ft lbs and 1000fps is probably not achievable but at leat hi 700’s to bottom 800 FPS would be nice
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Just found online the fac hammer and bought it. I already have the fac valve spring so that should compensate and with a little luck it may add a few more FPS. Thanks for all your help guys
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It might also have a smaller diameter valve seat. My unregulated Royale 500 came with a smaller seat, so they do switch things around for different gun designs.
Jking
Jking
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That’s an interesting thought. Where is the valve seat? Does the regulator port hole need to be bigger
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I get my power with the reg at 160. (61ftlbs) I dont think your reg is too high. I think its the other points you are exploring
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Perhaps change light hammer for heavier hammer and change regulator this may be enough. I drilled barrel to 8mm and the front wheel port hole to 7mm so a massive flow but is there anything else that needs to be drilled I have missed?
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Isn't there some 'hidden' widget on 12 lb guns that needs to be removed or adjusted. I recall seeing a foil covered piece that needed to be removed, then you could adjust it to the rest of the world's specs.
Maybe I'm off base here, but I recall something about it. Perhaps it was just one manufacturer doing that?
mike
Maybe I'm off base here, but I recall something about it. Perhaps it was just one manufacturer doing that?
mike
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You definitely need a hammer weight to crack open the valve at or above 150bar. You might be able to go over that pressure with a spacer to add hammer spring pretension, but I have spent a fair bit of time building hammer weights and finding the minimum hammer weight and spring tension to utilize higher reg pressure settings in my Crown.
I started off with the hollowed brass ER weight, which weighed in at 7.6(?) grams, which didn't open the valve over ~153bar (this causing velocity to drop past 153bar). I filled the weight with lead, increasing the weight to 9.9grams, which allowed me to open the valve over 160bar before velocity once again dropped.
Fast-forward to my current configuration, I'm using a 12.6gr hammer weight with a fair bit of spring pretension, and I can use all of the 190bar in my Huma extra-high pressure regulator for 76FPE in .22 caliber. I could probably do further tweaking and tuning and get the numbers up higher, but I'm VERY pleased with how my rifle shoots 28-30gr slugs closer to 60FPE and the shot count with that tune - so I'm not at all compelled to push it further at the moment.
The larger hammer weight also makes it difficult to tune for light pellets (<=16gr), but it has been very compatible for an 18gr pellet tune (@970fps with my 380mm barrel). If I want to shoot anything lighter, I have to reinstall the stock hammer spring guide and remove my weight.
I started off with the hollowed brass ER weight, which weighed in at 7.6(?) grams, which didn't open the valve over ~153bar (this causing velocity to drop past 153bar). I filled the weight with lead, increasing the weight to 9.9grams, which allowed me to open the valve over 160bar before velocity once again dropped.
Fast-forward to my current configuration, I'm using a 12.6gr hammer weight with a fair bit of spring pretension, and I can use all of the 190bar in my Huma extra-high pressure regulator for 76FPE in .22 caliber. I could probably do further tweaking and tuning and get the numbers up higher, but I'm VERY pleased with how my rifle shoots 28-30gr slugs closer to 60FPE and the shot count with that tune - so I'm not at all compelled to push it further at the moment.
The larger hammer weight also makes it difficult to tune for light pellets (<=16gr), but it has been very compatible for an 18gr pellet tune (@970fps with my 380mm barrel). If I want to shoot anything lighter, I have to reinstall the stock hammer spring guide and remove my weight.
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Karly im shooting a .25 cal 32.8 grain slug at 920 fps. I get about 35 shots on this tune. Its a monster from a 600mm barrel.
I wont say this is absolutely normal, as mike at utah air says i got a “hot one”.
But my point is my hammer is more than capable of dealing with reg pressures up to 160 bar. I believe my bar gauges as they are verified against other trusted gauges. I do not say or think that all fx factory gauges are accurate. Norms gauges gave him fits on his impact.
If interested we address my crown and some of the settings in “our gear part one”. And if you watch our hunts you can see how hard it hits even past 200. Its a beast in the world of crowns.
keith
I wont say this is absolutely normal, as mike at utah air says i got a “hot one”.
But my point is my hammer is more than capable of dealing with reg pressures up to 160 bar. I believe my bar gauges as they are verified against other trusted gauges. I do not say or think that all fx factory gauges are accurate. Norms gauges gave him fits on his impact.
If interested we address my crown and some of the settings in “our gear part one”. And if you watch our hunts you can see how hard it hits even past 200. Its a beast in the world of crowns.
keith
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That’s very interesting Keith, I really appreciate that
where can I watch “our gear part 1” ?
where can I watch “our gear part 1” ?
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Yeah it's possible Keith might have a spring that is heavier or cut / ground differently than most. I bought a bunch of different springs that were in and around the three Crown hammer springs and tested them out, but I still needed a weight to get my valve open up to my target pressures.
If all that you're looking for is low 160's, source some high quality springs using precision measurements from your factory spring and experiment
If all that you're looking for is low 160's, source some high quality springs using precision measurements from your factory spring and experiment
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I did put the fac hammer spring in which is slightly thicker but shorter than the UK version and it did make a real difference however I am certain you guys are right about the hammer itself. It all makes sense to put a heavier one in I’ve ordered an fac one so il weight it more with lead and see how that fares. Once I change the regulator I should be flying. Many thanks guys for all your valuable help
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