Tuning Fx crown reg creeping.

[airprsr]

I recently was lucky enough to obtain an fx crown .22 with a 500 mm stx barrel. I tuned it to shoot 22.5 .217 varmint knockers with the reg at 155 and hammer spring roughly tuned for best group/peek power. (No chrono just watching my groups shift.) Just now I was shooting and noticed it throwing flyers and increased air consumption. I checked the reg and it had gone to 148 from 155. Has anyone else had this? Did it just need to "settle" or wil it need a repair?

 

[nervoustrig]

Step 1: Do a little test to distinguish between creep or setpoint shift (whether due to break-in, self-adjustment, or some other reason).

Send a few shots downrange, record the pressure, then set it aside and record the pressure after 5 minutes, 10 minutes, 30 minutes, and an hour.

Step 2: Go online now and order a chronograph. Spend $120 for a full size one or $30 for one of clamp-on models, but get a chronograph. It is absolutely essential for any form of PCP tuning or troubleshooting.

Not having one is a false economy. Not just in the general sense but in the specific...already we can see you are hamstrung without one. Why do I say that? Well, if the air consumption went up as a result of the regulated pressure increasing from 148 bar to 155 bar, it means the hammer spring tension was set too high and it is tuned up on the velocity plateau, wasting air and negatively affecting the extreme spread.

 

[srtmat]

Is this a new gun? Regs can take some time to settle in when new.

I find it pretty common on my Crown if I adjust the reg up from say 140 bar to 145 bar I check it after 5 or 10 shots and it settles down a few bar 143ish. I just make small 1/8 turn adjustments shoot, settle in and repeat until it’s where you want it.

 

[airprsr]

UPDATE; Adjusted the reg up to155 again. Shot a dozen times or so, right back down to 148. Could it just be maxxed out?

 

[qball]

Nah, it’s just settling. Keep doing that till it settles on the pressure you want. 

 

[airprsr]

No I bought it used. 

 

[jmmartinez573]

I too have this happening, but only when I'm shooting light ammo on a heavy ammo/slug tune. I think the plenum does not get filled to set point pressure consistently when tapping the valve lightly on a high reg pressure. Once I pop in some slugs or heavy ammo and hit the valve hard, it fills the plenum to my set point. (150 bar)

Having a chronograph is a necessity if you want to the your airgun. Otherwise you are working blind.

 

[FX-USA]

I recently was lucky enough to obtain an fx crown .22 with a 500 mm stx barrel. I tuned it to shoot 22.5 .217 varmint knockers with the reg at 155 and hammer spring roughly tuned for best group/peek power. (No chrono just watching my groups shift.) Just now I was shooting and noticed it throwing flyers and increased air consumption. I checked the reg and it had gone to 148 from 155. Has anyone else had this? Did it just need to "settle" or wil it need a repair?

Hi Airprsr, 

If you are still facing difficulties and need some help please feel free to give our customer service and/or technician department a phone call/E-mail. 

Regards, 

FX Airguns USA

Contact 

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Fridays 9 AM - 3 PM EST
Phone: +1 866 639 0772
[email protected]

 

[airprsr]

Hey an update on my crown; Thanks for the helpful replies. I think what the problem is/was, was the reg just needed to "settle". After repeated adjustments ive gotten it to stay where I want it with this exception; when I put the gun away for a day or so the reg will creep upward as if it’s slowly leaking. However after one shot the pressure goes right back where it belongs. 
I would also like to respond to the comments I’ve received about a chronograph being essential. This is for others who may be on here who’s budget is strained nearly to the breaking point like mine by the price of these guns. While I intend to get a chrono when possible, ive certainly not found myself "hamstrung" without one. To tune the crown I set the reg where I wanted it then shot a series of three shot groups with different settings of the power wheel. In this way I was able to find the peek velocity for the reg setting as faster sluggs group higher. I then go to the next lower setting on the power wheel, which is where I get the tightest groups. (@ 1/2 inch at 50 yds.) My Dad always said there’s more than one way to skin a cat.

 

[qball]

Hey an update on my crown; Thanks for the helpful replies. I think what the problem is/was, was the reg just needed to "settle". After repeated adjustments ive gotten it to stay where I want it with this exception; when I put the gun away for a day or so the reg will creep upward as if it’s slowly leaking. However after one shot the pressure goes right back where it belongs. 
I would also like to respond to the comments I’ve received about a chronograph being essential. This is for others who may be on here who’s budget is strained nearly to the breaking point like mine by the price of these guns. While I intend to get a chrono when possible, ive certainly not found myself "hamstrung" without one. To tune the crown I set the reg where I wanted it then shot a series of three shot groups with different settings of the power wheel. In this way I was able to find the peek velocity for the reg setting as faster sluggs group higher. I then go to the next lower setting on the power wheel, which is where I get the tightest groups. (@ 1/2 inch at 50 yds.) My Dad always said there’s more than one way to skin a cat.

Good to hear you got it sorted. First shot reg creep is VERY normal after storage, there isn't a reg that doesn't creep over time although the dual reg M3 and Maverick do much better than single reg guns. Some people claim their gun's reg never creeps but that's because the tune is overpowering the HS/TP so the creep won't show. I can tune my crown to do that too but it won't be nearly as efficient, everything is a compromised. Just scrub 1 shot/dry fire before you shoot and problem solved! 



Only way to not ever have no reg creep is not to have a reg to begin with, but they are a PIA to tune in comparison with regulated guns.