If the POI doesn’t shift at 50 yards then there is no POI shift if you ask me. At 100 yards POI will shift based on environmental changes and wind. Curious on what mod you made to prevent POI shift.
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FX M3 Consistency After a time stored .. From an FX Hater ( Not )
- Thread starter wooferocau
- Start date
If the POI doesn’t shift at 50 yards then there is no POI shift if you ask me. At 100 yards POI will shift based on environmental changes and wind. Curious on what mod you made to prevent POI shift.
No problem
First bit is easy..
Starting with the FX liner and original steel barrel tube, Bond the FX carbon stiffener to the liner . Bond the liner and stiffener to the barrel tube. Bond the SS barrel nut to the barrel tube.
This is done with Loctite 680.
Machined a piece of 7075 seamless Aluminium tube to fit over the steel barrel tube. .005" clearance. This is then bonded using the Loctite 680. A carbon outer tube is then press fit over the aluminium tube .
I machined a replacement front receiver "clamping" block that has a extended cylindrical section that goes over a small step on the carbon tube. This is indexed and permanently bonded.
To remove the barrel assembly i undo the 2 cap screws through the forward barrel clamp and receiver .
Effectively the whole assembly is a complete bonded unit...its VERY stiff.
Since doing this mod i have had very consistent accuracy and POI..
The standard FX liner is obviously very accurate, but there is just to much flexibility in the original setup.
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I did not say it does not happen at 50yds or less...
I said...
Shooting at such close distances of 50yds or less will usually not show the issue as apparent as longer distances
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I would just like to verify my conclusion on my M3. Bottom target yesterday top target today, both 18 gr pellets, same distance no warm up shots either day,
30 yards because of wind 10+mph. Pulled the gun out of the safe by the moderator. 9 shots on top target 19 on the 2inch spinner @ 60 yards without a miss. You could say the spinner isnt a perfect group but really? its windy and I dont claim to be a pro. Your results may very
30 yards because of wind 10+mph. Pulled the gun out of the safe by the moderator. 9 shots on top target 19 on the 2inch spinner @ 60 yards without a miss. You could say the spinner isnt a perfect group but really? its windy and I dont claim to be a pro. Your results may very
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At 50 yards airguns are already affected by environmental changes and wind, if it's that hard to notice then it's probably external influences in my experience. Generally when people complain on the forum about POI it's very significant even at 20 yards, like half to an inch over which is very significant.
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I have shot at longer distances this is just what i have to work with in my yard, max 70. I did own an Impact when they first came out a few years back in .25 before slugs were being shot, at least by the masses and could hit shotgun shells consistently out to 135 yards with pellets (if the wind wasn't blowing)
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FX - Impact M3 ... POI change journey.
During a shooting session? So if you fire say a 10 rnd group ...then pause...another 10rnd group....pause and so on...say over a spread of 50 shots, the POI will remin fairly constant? Cause that is NOT what happens with my FX.. Have you taken off the barrel and made sure everything is nice...
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@wooferocau Have you checked that your probe has been tight thru all the problems with inconsistency? My Impact started giving me trouble while I was tuning a couple weeks ago and accuracy fell apart and started not making sense. I worked back thru all the settings and speed trying to get accuracy and consistency back without success until I checked my probe. The probe set screw was pretty loose. I tightened it and got results back in line. A few days later I started to have some flyers and inconsistency creeping in to groups again. I checked the probe set screw and sure enough it was starting to loosen up again. This happened three times for three different shooting sessions. I put blue loctite on it and that was the end of the issue.
For anyone else reading this thread check the probe set screw. I would also check that the sections of the impact that all line up that the barrel slides thru are all correctly in line and not putting stress on the barrel assembly due to not being lined up correctly. If the barrel assembly doesnt slide out or back in smoothly I would take the rail and backbone off and re align the assembly using the barrel assembly as the guide rod and then correctly torque the parts down in sequence. After its all re assembled pull the barrel assembly out and check for an even smooth removal and reinstall again checking that nothing binds or feels out of line.
I know these suggestions wont be the cause of some peoples issues but they could be or be one of multiple things causing a bigger problem. Stacking issues can be a big problem when multiple assemblies rely on each other to work correctly or consistently. Doesnt hurt to check everything when you are having an issue.
For anyone else reading this thread check the probe set screw. I would also check that the sections of the impact that all line up that the barrel slides thru are all correctly in line and not putting stress on the barrel assembly due to not being lined up correctly. If the barrel assembly doesnt slide out or back in smoothly I would take the rail and backbone off and re align the assembly using the barrel assembly as the guide rod and then correctly torque the parts down in sequence. After its all re assembled pull the barrel assembly out and check for an even smooth removal and reinstall again checking that nothing binds or feels out of line.
I know these suggestions wont be the cause of some peoples issues but they could be or be one of multiple things causing a bigger problem. Stacking issues can be a big problem when multiple assemblies rely on each other to work correctly or consistently. Doesnt hurt to check everything when you are having an issue.
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Virtually every reg can/will creep to some extent. It is just the nature of the design.
There are ways to mitigate it though if you need that first shot to matter and can't purge your gun. Depending on the severity of the reg creep, if you find your ideal velocity/reg pressure/HS settings, then back the reg off 3-5 BAR, your velocity will be virtually unchanged but when the reg creeps back up the valve is still able to be opened all the way by the hammer so there is no discernible POI change.
I forgot who I heard that from originally. Not my idea. A bunch of FT shooters I know used to tune like that since at GP matches a rifle might sit for 30 minutes in between lanes.
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I figured you would have already gone thru all those suggestions but someone else may just be starting down the road of finding issues or just making sure everything is as good as it can be.@LDP
Thanks for the input
All info/suggestion put forward has to potential to help improve the FX M3 experience.
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The harmonic problem of POI is not very clear. Can you explain it in more detail? The carbon fiber casing is bonded to the inner lining, and then the carbon fiber is bonded to the outer tube. How to do it in the end?
The outside of the outer tube is the shield. Where is it installed using 7075 aluminum tube?
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Some other food for thought is true poi shift in my mind would be harder to really conclude as true poi shift at long ranges unless you are in a 100 yard indoor range. We shoot very light projectiles and the slightest difference in atmospheric and weather conditions from day to day can shift poi for sure. Is it really the gun 
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Or you can increase the hammer close to the plateau, that will overcome some creep. I'm fine with my first shot ~10 fps lower and from there dead on
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