Tuning FX Impact Mk2/M3 - slower first shot - no reg creep - quasi-scientific analysis

[PcpMachinist]

I can tell you that I have installed the 'special' O-Rings in my M2. I STILL must fire at a minimum of 9 shots for the velocity to come up to the setting. This with polishing the rod.
Starting at 813 and growing in increments of around 10-15FPS until reaching 925FPS.
Do the magical O-Rings work for me? Nope!

mike

and your gun has more issues than o rings I'm sure try using dry air .
and learn how to diagnose your gun you will be allot better off.
you will learn some day don't worry it comes in time..
i been into this hobby for 35 years now ,seen allot been to the Fx factory 4 times been to daystate browning Remington etc.
hmm oh NOW ITS MAJICAL O RINGS and YES THEY WORK problem is you have no idea how to diagnose
None of my guns have your problems so maybe you might want to look in other places Majic lol...
this thread is like whipping a dead dog never seen such a site must be nice to know everything.
i see what the others mean by this website is like the view, more covid shots..

 

[thommy]

I've been using the Mubhaur component for a few weeks now. But I can't get rid of that first slow shot after a 12-hour break. I do want to emphasize that the M3 is spot on after that first shot; the velocity is almost clock-steady! Following Mubhaur's advice, I increased the spring tension a bit and closed the valve adjuster a bit more, but after about 1000 shots, this did not solved the problem. I should also mention that I also installed the new valve rod kit along with the Mubhaur pelnum end. Of course, everything was polished up nicely. The first shot after a long break is 16.40 fps (5 m/s) slower. All in all, I'm satisfied, and as a benchrest shooter, it doesn't bother me much. The fact is, the rifle now generates almost clock-steady velocities.

 

[Ries]

im not mad and fact is none of my guns have an issue with this slow shot problem so it sounds to me
like you have not found your issue, its not just the o rings..
have you ever seen what an o ring does under extreme pressure in a conical seat?
you may want to take a look of do some reading up on it..

I know what it does. Look post above, someone said the orings didnt even work in his impact. It looks like you trying to sell the orings, lol.

Since I have a modified plenum neck where the oring sits flush and not conical, my problem is gone. Hmmm..

Believe what you want, lets get back to shooting.

 

[CrashKT]

I've been using the Mubhaur component for a few weeks now. But I can't get rid of that first slow shot after a 12-hour break. I do want to emphasize that the M3 is spot on after that first shot; the velocity is almost clock-steady! Following Mubhaur's advice, I increased the spring tension a bit and closed the valve adjuster a bit more, but after about 1000 shots, this did not solved the problem. I should also mention that I also installed the new valve rod kit along with the Mubhaur pelnum end. Of course, everything was polished up nicely. The first shot after a long break is 16.40 fps (5 m/s) slower. All in all, I'm satisfied, and as a benchrest shooter, it doesn't bother me much. The fact is, the rifle now generates almost clock-steady velocities.

View attachment 595686

View attachment 595687

I mean, if it's in that first to fifth shot, I'm ok with that. Especially if consistency is there too.

 

[Revoman]

PcpMachinist​

Hmmm....I might assume that sending this rifle back to UA and having them 'fix' it and them install the O-Rings that I provided, I am to blame for not knowing my rifle and finding the issue.
Nice argument.
It's NOT me that said, "I know everything!", it's YOU.
Your rants mean zippo to me, other than when I get called out.
BS

mike

 

[mubhaur]

I am sorry to know that but I still understand that you can find the right tune

 

[Revoman]

mubhaur​

Happy to hear from you.
I believe that I currently have the right tune.
My M2 is a .25 Caliber, shooting 25.4gr pellets at + - 925FPS, I am getting up to 142 shots from a 250bar fill using a 580cc bottle.
I am very happy with the accuracy at that speed and getting that many shots from a fill is great.
That is running the fill down to just a shave past my regulator setting of + - 135bar. I normally top off just before that mark but decided to take it down a touch further to see just how many shots before accuracy dropped off (accuracy never did drop off, even after just below reg pressure, but I decided to stop to not harm the valve pin). So, even if I'm getting around 130 shots, that to me is a good tune.
The only issue is that fact that the first 8-9 shots are not up to speed after highly polishing the rod, plus using the (now) recommended O-Rings.
I'm not going to try and better that tune just because of another opinion, it's good in my view..
As always, I thank and respect your viewpoint and contributions to the air gun hobby.

mike

 

[mubhaur]

mubhaur​

Happy to hear from you.
I believe that I currently have the right tune.
My M2 is a .25 Caliber, shooting 25.4gr pellets at + - 925FPS, I am getting up to 142 shots from a 250bar fill using a 580cc bottle.
I am very happy with the accuracy at that speed and getting that many shots from a fill is great.
That is running the fill down to just a shave past my regulator setting of + - 135bar. I normally top off just before that mark but decided to take it down a touch further to see just how many fills before accuracy dropped off (accuracy never did drop off, even after just below reg pressure, but I decided to stop to not harm the valve pin). So, even if I'm getting around 130 shots, that to me is a good tune.
The only issue is that fact that the first 8-9 shots are not up to speed after highly polishing the rod, plus using the (now) recommended O-Rings.
I'm not going to try and better that tune just because of another opinion, it's good in my view..
As always, I thank and respect your viewpoint and contributions to the air gun hobby.

mike

Your issue should be resolved with my after market part as I understand

 

[UDABEGGER]

and your gun has more issues than o rings I'm sure try using dry air .
and learn how to diagnose your gun you will be allot better off.
you will learn some day don't worry it comes in time..
i been into this hobby for 35 years now ,seen allot been to the Fx factory 4 times been to daystate browning Remington etc.
hmm oh NOW ITS MAJICAL O RINGS and YES THEY WORK problem is you have no idea how to diagnose
None of my guns have your problems so maybe you might want to look in other places Majic lol...
this thread is like whipping a dead dog never seen such a site must be nice to know everything.
i see what the others mean by this website is like the view, more covid shots..

What does covid shot have to do with PCP shots ?

 

[CrashKT]

What does covid shot have to do with PCP shots ?

Angry old man with access to the interwebs....