FX Fx amp reg brass piston reg creep? (Updated after polished)

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Shinyknight

Shinyknight

Member
Feb 26, 2019
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Minnesota
Sorry guys I know this topic of the reg creep have been discussed many times. But this drives me crazy that it's still doing it after buying the brand new brass piston and it still does it. Everyone knows fx amps reg is prone to reg creep cause they used a plastic piston. So I ordered the new brass piston and installed in my impact mk2 and find out I'm still getting reg creep. I set reg to 145 bar. Shooting 36gr nsa slugs at 960-970 fps. Let the gun settle down for the night. Check and reg went up to 155 bar. I think might be the gauge not accurate so swap gauge from bottle and place in the reg port. Using wika qauges, not fx gauges. Still climbing from 145 to 155 bar over a few hours. So got chorny out to test what the first shot is. I find out first shot is shooting 36gr nsa at 870 fps. I was like that can't be. Shot the 2nd shot and it climb to 940 fps. Then 3rd shot climb to 960fps. 4th and upper shots settle in 960-970 fps. That's about 100 fps from 1st shot to when it settle down. This is unacceptable imo. For a 2k gun. I thought buying this new brass piston will fix the problem but still doesn't. Most guys will just say, well dry fired 2-3 shots. But when you out hunting you cant afford to fire any shots and scared away what you are hunting. I watch a lot of Matt dubber videos and he seem to be really knowledgeable on the impact but never have he mentioned anything about the impact having reg creep problems. Smh. Anyone else getting reg creep with the new brass piston?

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Since you have changed the reg piston, maybe it is the surface on the tip of the adjuster screw which have a microsopic imperfection? There is two surfaces which make the seal, not just the piston surface
A tiny scratch on the surface not being seen by naked eye, can lead to a small bypass of air, or creep.
Ernest Rowe has a video showing how to polish that surface
I would try to polish the surface on the adjuster screw, like how he doeas, and try again.
Maybe after that shoot a few hundred shoots to see if it improves, without doing any major adjustement?
 
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I did not polish anything. I just simply installed the brass piston thinking it would fix the reg creep problem I was having with the plastic piston. I will have to take the reg out again and try polish it and see if that will help. If the problem really is just to polish it. Why doesn't fx do that at the factory so customers do not have to. If they paid $2199 for a gun they shouldn't have to do anything to it.
 
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Shinyknight said:
I did not polish anything. I just simply installed the brass piston thinking it would fix the reg creep problem I was having with the plastic piston. I will have to take the reg out again and try polish it and see if that will help. If the problem really is just to polish it. Why doesn't fx do that at the factory so customers do not have to. If they paid $2199 for a gun they shouldn't have to do anything to it.
Click to expand...

Which is why I don't own, nor will ever own, any fx air rifles. So many people claim their build quality justifies the price, frankly, coping mechanisms are strong, no pellet gun should cost over 2 grand unless its due to inflation and the year is 2320...

-Matt
 
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to a minor degree I see this with all the brands I have owned.
Even with Huma Regs. or RAW or Air Arms, but
Not as drastic as what you are seeing. I see mine in reduced fps not 10 bar.

That said I think the AMP design because of its size and desire to be externally adjustable adds to the potential for leaking of O-rings from the bottle side to the plenum side.

What level of fill is your tank when you are getting this creeping?
 
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Shinyknight said:
I did not polish anything. I just simply installed the brass piston thinking it would fix the reg creep problem I was having with the plastic piston. I will have to take the reg out again and try polish it and see if that will help. If the problem really is just to polish it. Why doesn't fx do that at the factory so customers do not have to. If they paid $2199 for a gun they shouldn't have to do anything to it.
Click to expand...
Ahhhh, the eternal FX and "why didn't they" question, right along with the chicken and egg question. Personally I'm tired of chasing that, I've polished and I still have a bit of creep, and not only on my Mavericks, my first shots are a touch fast then settle down, I'm not going for a $25,000 check so....meh, 5 fps more isn't a deal breaker but for us OCD types it is annoying to say the least.
 
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HogKiller said:
Ahhhh, the eternal FX and "why didn't they" question, right along with the chicken and egg question. Personally I'm tired of chasing that, I've polished and I still have a bit of creep, and not only on my Mavericks, my first shots are a touch fast then settle down, I'm not going for a $25,000 check so....meh, 5 fps more isn't a deal breaker but for us OCD types it is annoying to say the least.
Click to expand...

This is where unregulated guns shine for those not chasing $25,000 checks, who are just casually shooting. Keep your pressure in right range you can achieve single digit ES, with one less component to worry about either failing entirely or causing cold shot issues. Definitely helps those with OCD as well...you cannot beat that kind of reliability and consistency with a regulated gun, period.

But marketing hype and chasing the latest and greatest bell and whistle is what forces everyone to think they HAVE to run regulated these days. A very well 'self regulating' valve is far superior to regulated guns for your casual shooter, imo. Also no need for a secondary reservoir aka plenum.



-Matt
 
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Ok so updated.
Yesterday I took about an hour and a half polishing the brass piston, the reg housing, valve adjustment screw, and even the washers. I installed it and fill gun to 220 bar. The reg is set to 145 bar. I fired 5 shots to get a idea what the speed is. So this is 5 shot string.
960, 967, 971, 969, 969 fps.
I let the gun sit overnight. When I checked this morning the reg is at 150 bar. I guess 5 bar increase is normal? I went to test for speed. These are the 5 shot string.
939, 959, 966, 970, 970 fps.
It is better than b4 I polish it. Before the 1st shot was 860. Then jumps to 960s. Now the first shot is 939. With tuning I think I can get first shot close to the 960-970. For anyone who is getting reg creep and low speed on the first shot, I recommend polish everything you can. It does help.
 
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Shinyknight said:
Ok so updated.
Yesterday I took about an hour and a half polishing the brass piston, the reg housing, valve adjustment screw, and even the washers. I installed it and fill gun to 220 bar. The reg is set to 145 bar. I fired 5 shots to get a idea what the speed is. So this is 5 shot string.
960, 967, 971, 969, 969 fps.
I let the gun sit overnight. When I checked this morning the reg is at 150 bar. I guess 5 bar increase is normal? I went to test for speed. These are the 5 shot string.
939, 959, 966, 970, 970 fps.
It is better than b4 I polish it. Before the 1st shot was 860. Then jumps to 960s. Now the first shot is 939. With tuning I think I can get first shot close to the 960-970. For anyone who is getting reg creep and low speed on the first shot, I recommend polish everything you can. It does help.
Click to expand...
Glad it worked for you. How, exactly, did you polish the parts? And, did you mean that you polished the reg washers?
By the way, 3-5 bar creep is pretty normal if you are at the same temps. What is the difference between 1st and 2nd reg?
 
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Patrick1 said:
Glad it worked for you. How, exactly, did you polish the parts? And, did you mean that you polished the reg washers?
By the way, 3-5 bar creep is pretty normal if you are at the same temps. What is the difference between 1st and 2nd reg?
Click to expand...
It's mk2. So only 1 reg. As for polishing the washers, check this video. I copy what he did. Check at 12:40. He show how to polish the washers. I just copy what he did.
 
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