FX FX Impact M4 - Velocity consistency?
- Thread starter Xcaliber
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You can contact him here at the forum @mubhaur , i'm sure he will get back to you.
I dont remember exactly how much I paid. I was going to sell my Impact due that slow shots issue.
I am not permitted to hunt with airguns in my country, but I want to pick it and start enjoying it without having 4 warm up shots.
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Over night Oct 10 - 11 the temperature dropped from 78°F to 45°F and my .30 M3 was in the van. In the morning I found the tank pressure had slightly decreased but 1st and 2nd stage pressures were normal meaning that as the plenum cooled down the regulators did their thing and maintained pressure.
At the range (2 pm on the 11th) the temperature was 81°F, the tank pressure was back to normal with the plenum pressure half a gauge indicator needle width high.
First shot of the day was at 100 yards using my normal hold over and the shot hit high in the 4" diamond. 2nd shot 2 minutes later using the same hold over was in the near center of the 2" diamond. 3rd shot 2 minutes later was the same touching the 2nd shot and regulator output pressures were normal.
Target is a 2" tip to tip diamond inside a 4" inside a 6" inside an 8" tip to tip diamond.
At the range (2 pm on the 11th) the temperature was 81°F, the tank pressure was back to normal with the plenum pressure half a gauge indicator needle width high.
First shot of the day was at 100 yards using my normal hold over and the shot hit high in the 4" diamond. 2nd shot 2 minutes later using the same hold over was in the near center of the 2" diamond. 3rd shot 2 minutes later was the same touching the 2nd shot and regulator output pressures were normal.
Target is a 2" tip to tip diamond inside a 4" inside a 6" inside an 8" tip to tip diamond.
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A lot of the first low shots and not being able to hunt is way overblown. There are very simple fixes for it. I had a BRK Ghost for awhile and it would get a bit of reg creep which would give me a low first shot. It’s worse with the Impact, but that Impact will outshoot a ghost any day of the week.
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I'm surprised there is 61% as of writing this that are getting same speed. I own an fx impact (says in my name lol). I have use fx amp reg gen 3, also used huma reg, and then tired m4 reg with brass piston. All will creep about 5 bars over night and speed will be lower by about 40-50 fps using 33.9gr jsb heavy mk2. So I find it hard to believe that there is 61% getting same speed. Woozers. None of my other guns does this. I believe the fx impact have this issue due to the small reg. It's like 3 times smaller than any other regs on my other guns.
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Based on what I've researched on this issue, the cold shot symptom goes way back to the M3 days, i read some owners decided to take apart their M3, thoroughly clean the valve rod when they found some grease on it and the o'rings, put them back together, and no longer see the discrepancy after overnight, same fps for cold shot, while few others only had the issue developed few months later, they did the same thing to take it apart for cleaning and lubing with silicone oil, but installed the "fix" made by mubhaur, which look like a plenum cap holding the valve rod, the "fix" also mitigated the issue.
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If you were to hunt, and aiming at a grounhog or squirrel at 100 yard, how far off is that very first cold shot going to be? about 2" higher? if it was a deer that you're shooting at, would it be off far enough to miss the vital organ completely?
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I run a Huma in my impact X with 720 plenum and powerblock, I dont see any creep since I switched to Huma.
I tried all things to my AMP, even the brass piston. But the creep came back sadly.
The first slow shot is due o ring stiction on the valve rod if you dont have reg creep.
I mirror polished my valve rod and then installed Mubhaur his part and started tuning.
My first shot cold shot is gone, its maybe 5-7 fps slower but at 50 yards its spot on the first shot.
I remember the first shot being like 70-80 fps slower and would take 4 shots to settle..
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I keep hearing about this mubhaur thing. Where can we order one? Importantly, how much? Does he ship to US? Link to this item? I have huma gen 3 reg on my impact. Still creep about 5 bars. I am getting 40-50 less on my first shot. If I can get it down to 5-7 that would be great.
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If I have a raccoon coming to the bait station, I will take a few shots before I go to bed and it is fine by the time the motion sensor goes off. If I’m going hunting I’ll take a few shots before. Big whoop!
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The target design of a diamond and the size of the diamonds is based on measurements of adult groundhogs. In their upright sitting position using a POA of widest center mass that 1st shot would have been a fatal hit.
I always aquire first, then click my tongue once to get them to sit up. As long as you don't move they won't and you just squeeze one off.
Had I been going for a head shot, that first shot on Friday would have been a miss.
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I ordered it from him via a private message on this forum. Maybe you can ask him in private message what it would cost.
He is from Pakistan, he shipped to Belgium without issues. Shipping only took like 3 days with DHL.
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I have a theory about what befuddles you. When a certain reviewer was reviewing the M3, I saw his wonderfully flat graphs of his shot strings. I asked him to do a graph that included his first shots of the day. He still insisted there was no first shot or shots issue. His tuning process produces flat strings. But after some badgering, he said he always fires a couple dry fires to “settle the regs”. My guess is the majority of that 61% has the exact same velocity the next day so they aren’t being dishonest. They just “settle their regs” first. Monkey see monkey do.
I can almost promise you, if you tune an Impact on the knee, even with a peek washer or MKl plenum plug, you are getting slow first shots. Polishing the hell out of your valve rod is a double edged sword. You almost need it to be porous to hold lube and keep it operating smoothly. I mildly polish mine in the critical areas and use a special lube. Not silicone.
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I kinda agree with you on that..even Matt dubber and south African guys shooting over 150-200 yards. At that distance 50-70 fps slower will make a difference but they never mention it or show it. They only show us what they hit their target. I'm sure they also dry fire a shot or two to settle the reg before shooting past 100 yards.
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I have 4 M3's and now an M4, I do a ton of posting and I don't have this issue. They will fluctuate when they are new, but once broke in you should be good to go
I am running 150 bar plus on most of my guns and shoot slugs so maybe that's why? Hell even super cold temperatures don't even affect them
Also my 800mm setup i run a huma reg and it does not creep at all
I am running 150 bar plus on most of my guns and shoot slugs so maybe that's why? Hell even super cold temperatures don't even affect them
Also my 800mm setup i run a huma reg and it does not creep at all
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Well this specific poll seems to prove that there are those who can correctly tune and accurately shoot an Impact and enjoy the rifle and then there are those who cannot and bitch.
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Just curious, what caliber and slug weight are you powering that would require reg at 150 bar? I have a few boxes of 35gr and .38gr NSA slugs in .22, haven't try them yet as I don't think my M4's stock hammer is heavy enough to hit open the valve at 150 bar. In a stock form with 600mm barrel and zero upgrades, my M4 seems to be most comfortable and quietest to run at sub 50ft-lb @120 bar on the reg.
Last i checked, Matt Dubber was running his at 165~170 bar for .22 38gr and .40gr but his impact is fully tricked out, heaviest hammer, slug kit, 700/800mm barrel and the whole nine yards.
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