FX FX impact M4 velocity “warm up”

Ya that’s crazy unfortunate for a 2k gun. My $400 Turkish reximex wasn’t shot for 3 weeks. I left it at 918 FPS. Fired it yesterday at 917FPS first shot.

This should not be allowed on a gun that costs that much. Even 2-3 shots to “warm” it up seems weird.

Imagine telling someone who shoots powder. You need to shoot 3 times before your gun will be accurate. You think anyone would buy that gun

Mike
 
I wonder how long they will take to resolve these known issues in their flagship guns.
It’s crazy when you think about it… I think I am done with FX, the M4 is likely my last. I get design/ engineering trade-offs and can live with a slow first shot for the sake of a balanced valve if I have to (or simply click the hammer up for the first shot), even though you solved it… But this one is just lazy QC. Buy a new glorified pellet gun for more than $2k and the first thing you gotta do is take it apart and clean out too much/the wrong grease or whatever gunk applied by the factory to make it behave at anything but low power?! WTF… don’t get me wrong, it’s an awesome gun once the the bugs are fixed but this is not the first generation impact. It’s outright offensive that FX still relies on the end user to fix this nonesense. Looking at you, creeping reg, sticky valve and (at least up to the M4 but let’s see) moving barrel… and apparently now also at valve rod gunk.

That said, you really have to find a manufacturer for your part in the US! It’ll probably sell like sliced bread…
 
All I see is people having to polish the internals and having to buy this after market plenum thing that's made by a guy in India. Like wtf. For a $2199 gun, I believe we shouldn't have to take our gun apart to polish all the internals or having to buy after market parts from oversea to make the gun shoot right. It should come out of the box perfect. Zero reg creep, zero fps drops from shot 1 to when pressure falls off reg, zero poi shift. This is crazy imo. Kinda mad we have to pay extra on an already expensive gun.
 
Same deal with the Panthera / Dynamic / King.

After a good bit of tuning polishing etc. my gun is almost perfect, except for the first 2 shots after not using it for a while. This is tuned @950, about 50 fps below the knee, which is where my gun is most accurate after the 'warm up' shots with the projectiles I use.

Also, check when you fill the gun; i found the reg needle moves up as you fill it, causing similar issues to the decribed warm up shots.

I feel it's valve stiction combined with reg creep that is at the root of most described FX consistency issues found online. (plus lack of quality control during manufacture)
 
But don’t forget that
All I see is people having to polish the internals and having to buy this after market plenum thing that's made by a guy in India. Like wtf. For a $2199 gun, I believe we shouldn't have to take our gun apart to polish all the internals or having to buy after market parts from oversea to make the gun shoot right. It should come out of the box perfect. Zero reg creep, zero fps drops from shot 1 to when pressure falls off reg, zero poi shift. This is crazy imp. Kinda mad we have to pay extra on an already expensive gun.
but don’t forget that all those South Africans never miss a shot 😁

Now, excuse me while I go polish the valves in my new car’s engine so I can drive to the grocery store.
 
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All I see is people having to polish the internals and having to buy this after market plenum thing that's made by a guy in India. Like wtf. For a $2199 gun, I believe we shouldn't have to take our gun apart to polish all the internals or having to buy after market parts from oversea to make the gun shoot right. It should come out of the box perfect. Zero reg creep, zero fps drops from shot 1 to when pressure falls off reg, zero poi shift. This is crazy imo. Kinda mad we have to pay extra on an already expensive gun.
That’s how it should be. Even more so on the n-th generation of the gun with literally ALL ISSUES AND ALL SOLUTIONS KNOW for years. Zero excuse for not having them fixed. Ah well, fool me once, shame on you; fool me twice, shame on me… So this one is on me, they’re not going to fool me a third time though.
 
I’m wondering if someone can shed some light on this question.

I’ve recently got an FX Impact M4 .22 700mm with slug power kit installed, heavy liner, carbon sleeve etc.

If the rifle has been resting (but is room temperature) I notice it takes a good 10-15 shots for the velocity to get to where I tuned it (1000 fps)

I’m shooting 34gr slugs, at the beginning of the first few shots from resting overnight the chronograph will show it starts at around 890fps, then by about its 15th shot it’s got back to where I tuned it to at around 990-1000 fps and works like a laser, I would expect a few shots to be sluggish to awaken the air system up, but 15 seems a lot to me.

Maybe there’s a solution or maybe it’s normal..?

What’s everyone’s experience?

My settings are - 165 reg pressure, macro 13, micro 3.5, valve 4 lines.

Thanks all

When you installed the slug power kit, did you swap out the lighter valve spring and also insert that plastic ball? I was told the M4 does NOT need that plastic ball. Here's what you can try, drop your reg pressure down to 150~155 bar, up your micro to 4~4.3, open the valve a bit more to 4.5~5, and see if it help minimize the huge velocity gap you're seeing with 80fps difference is unacceptable, it sucks bad to take 10~15 shots to get up to speed.

Having your reg at 165 bar, that's a lot of pressure that would require much heavier hammer to strike open that valve, the two little washers probably not gonna cut it, especially when you intended to keep your M4 close to maximum power level for the long run, you can try a MUCH heavier Tungsten hammer, which is more suitable for reg living in 160~180+ bar, might as well upgrade to Huma's high pressure reg, that's what I would do if i were to shoot mostly 35~40gr heavy slugs all the time, and demand absolute powar and did not care about shot count.😁
 
As much as I like my modified M3,s.....i would never purchase another FX..
I'm in the same boat as Mr. Woofer. I really like my M3. But, because of this issue and the fact that FX continues to ignore it, I will never purchase another FX. I wonder how many members here feel the same? Maybe a poll to ID lost FX customers? Just a thought.

Cat
 
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FYI, reached out to UA given that FX USA is no more since mine is doing the same on a higher power tune and they confirmed that this is a know issue and that cleaning and lightly polishing the valve rod is the solution. Can be fixed by UA under FX warranty of course if you’re not comfortable with breaking the rifle down yourself.
If cleaning and polishing the valve rod is the solution, let us know. Because all of us that have been doing this for the last four years trying to fix the issue will need to attend their polishing seminar. That would mean all the parts we are machining for this gun to really help with the issue are a waste of time.
 
If cleaning and polishing the valve rod is the solution, let us know. Because all of us that have been doing this for the last four years trying to fix the issue will need to attend their polishing seminar. That would mean all the parts we are machining for this gun to really help with the issue are a waste of time.
Not the solution for the first slow shot, only for needing “more than one or two… meaning if you need 15, then it’s the valve rod. If you need one or two, then it’s just FX being FX…
 
I present to you: M4 valve rod gunk, newest feature… after cleaning and polishing the rod the gun is uber consistent again…

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I present to you: M4 valve rod gunk, newest feature… after cleaning and polishing the rod the gun is uber consistent again…

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Yep I did the same process as yourself and found that solved the issue, I also lightly lubed the rod with silicone oil before putting it all back together, then a drop or two of silicone oil in the fill hose of my compressor just before filling the rifle up.

It now takes just 2-3 shots to get it up to its tuned velocity & not 10-15.

My rod was all gunked up too (not as bad as yours though) after just 300 slugs fired through it, maybe the residue of it being new and not yet worn in ?

Hopefully it won’t happen again or any where near as bad.