FX Lock this thread please- Discussed with Fredrik, there is no evidence of POI shift in FX barrel liner system

mubhaur

Member
Nov 8, 2015
2,367
1
1,204
53
Karachi, Pakistan
I had a chance to talk to Mr. Fredrik while I congratulated him on new product line.

On a side note I mentioned that I understand that the issue of POI shift in FX liner system as we read on forums will now be fixed as FX now installs the liner either inside the cylinder or inside the plenum. This will help avoid the affects of undue external factors causing POI shift.

Fredrik very kindly advised that in fact when we examine the perceived issues of POI shift, there is no such evidence.

I understand that when a lot of customers purchase a certain product, the ratio of good and bad experiences remains same but the instances increase a lot.

Then again the happy users do not come to forums to complain but the dissatisfied users come to forums to speak.

Hence we see negative posts. This is like exception reporting during an audit.

The main advice of Fredrik about such POI shift is that we should clean the barrel as it changes POI.

He explains that the POI shifts only due to dirty barrel.

I share it as I feel it will be helpful for the users.

Happy shooting.

Regards,

Bhaur
 
Well, I beg to differ with Mr. Axelsson. I think there is ample evidence that the previous generation liner system suffered POI changes far more frequently than solid barrels. When I think of the original design, I'm reminded of my mom's frequent criticism, "what were you thinking?" It was redesigned for a reason.
 
Well, I beg to differ with Mr. Axelsson. I think there is ample evidence that the previous generation liner system suffered POI changes far more frequently than solid barrels. When I think of the original design, I'm reminded of my mom's frequent criticism, "what were you thinking?" It was redesigned for a reason.
Would you please discuss about previous generation liner system vs new generation liner system. Didn't know about it.

From new generation liner system, do you mean liner inside the cylinder or plenum?
 
I’ve been shooting pcp rifles now for a little over 15 years. It has been my experience that every single rifle I have owned during that time has experienced some degree of POI shift from one outing to the next. Not one of them has remained exactly spot on at 50 yards from one hunting trip to the next. That’s why I made a routine of checking zero at the start of every single hunting day. Now I’m talking about very minor shifts of say a quarter inch to maybe three eights inch at 50 yards but still a shift. I just considered it a fact of pcp life. I’m not picking on any one brand. Over the past 15 years I’ve owned rifles from Air Force, Air Arms, Edgun, FX, Daystate, Benjamin and Kalibr. They have all shown this behavior. I will say that I have owned an FX Panthera since October and it does seem to have the least amount of shift from one outing to the next. Not zero shift but much less than I’ve been used to.
Kenny
 
I’ve been shooting pcp rifles now for a little over 15 years. It has been my experience that every single rifle I have owned during that time has experienced some degree of POI shift from one outing to the next. Not one of them has remained exactly spot on at 50 yards from one hunting trip to the next. That’s why I made a routine of checking zero at the start of every single hunting day. Now I’m talking about very minor shifts of say a quarter inch to maybe three eights inch at 50 yards but still a shift. I just considered it a fact of pcp life. I’m not picking on any one brand. Over the past 15 years I’ve owned rifles from Air Force, Air Arms, Edgun, FX, Daystate, Benjamin and Kalibr. They have all shown this behavior. I will say that I have owned an FX Panthera since October and it does seem to have the least amount of shift from one outing to the next. Not zero shift but much less than I’ve been used to.
Kenny
Do you feel that Panthera shifts less POI as compared to other PCPs as it has its liner inside the protected plenum?
 
Would you please discuss about previous generation liner system vs new generation liner system. Didn't know about it.

From new generation liner system, do you mean liner inside the cylinder or plenum?
I'm referring to the original FX liner system. I haven't owned one since, so I can offer no experience on any improvements. But to say the original design had no POI problem is just not accurate.
 
Do you feel that Panthera shifts less POI as compared to other PCPs as it has its liner inside the protected plenum?
I can’t say that for certain, but that plenum over barrel is the only major change for the Panthera when compared to all the other rifles I have owned. I’ve also only had the Panthera since October so my experience is still new.
 
  • Like
Reactions: mubhaur
I had a chance to talk to Mr. Fredrik while I congratulated him on new product line.

On a side note I mentioned that I understand that the issue of POI shift in FX liner system as we read on forums will now be fixed as FX now installs the liner either inside the cylinder or inside the plenum. This will help avoid the affects of undue external factors causing POI shift.

Fredrik very kindly advised that in fact when we examine the perceived issues of POI shift, there is no such evidence.

I understand that when a lot of customers purchase a certain product, the ratio of good and bad experiences remains same but the instances increase a lot.

Then again the happy users do not come to forums to complain but the dissatisfied users come to forums to speak.

Hence we see negative posts. This is like exception reporting during an audit.

The main advice of Fredrik about such POI shift is that we should clean the barrel as it changes POI.

He explains that the POI shifts only due to dirty barrel.

I share it as I feel it will be helpful for the users.

Happy shooting.

Regards,

Bhaur
And my experience has been, a 'clean' barrel opens up the groups until it gets 'dirty', then they tighten up again. Now, it's possible that a chunk of lead gets lodged in and that causes the issue, you clean it out, then things start to settle in as the 'dirt' build up.
 
When one has to install 1, 2 or maybe even 3 barrel bands on a rifle to help minimize POI shifts, I would reasonably determine that barrel cleaning has little or nothing to do with those POI shifts. Mine would have a significant POI shift right after filling the rifle with air. How would that be impacted by a dirty barrel?
Thx
Dan
 
When one has to install 1, 2 or maybe even 3 barrel bands on a rifle to help minimize POI shifts, I would reasonably determine that barrel cleaning has little or nothing to do with those POI shifts. Mine would have a significant POI shift right after filling the rifle with air. How would that be impacted by a dirty barrel?
Thx
Dan
Your initial statement is very logical that if the system doesn't have issues then why many fixes are offered by FX.

But the other thing that you mentioned is that POI shifts after taking a refill, needs discussion.

I understand that FX Impact platform is well thought of and the bottle is not attached to barrel or any other part of the gun except where the bottle is attached to the gun.

In this scenario, the refill CAN NOT affect POI.

The only reason of change in POI after refill may be that the regulator pressure shifts a bit at higher bottle pressure. We can't find the difference until we install digital guage.

In order to address this issue, M3 uses two regulators.

I hope it makes sense.
 
  • Like
Reactions: MEC17670
I am not hunting or pesting with my air rifles, I am shooting paper rings only, some @ 50 meters but mostly 100 M, and exclusively in a gun club ranges.
I have a very firm standpoint what people referring to a "point shift".
I don't want to steer the pot, but just saying, you shall not take a Tylenol but find a source of the problem for a headache.
The biggest mistakes people do is not taking a consideration what Twist Rate and what Speed for a given projectile shape and weight.
There are other threads about this topic where big Names are talking, so finding it not necessary to repeat again here.
A quick recap...
If you lower or higher the speed by 10 fps or even better 5 fps increments in several steps, you will see the POI shifts around the POA, considering that your tune was already perfected. FX or not FX but pretty much all the same.
The weather, humidity, all adds up...you shoot in the morning or at noon or afternoon, all will alter the POI at some percentage...
This my observation from shooting large volumes @ BR and using a fixed rail. So the human factor touching the gun is minimized.
 
I was getting POI shift in a dreamline compact and was able to replicate it by tapping the barrel in 4 locations, up/down/left/right, and the pellet impact would move to the opposide side of where I impacted the muzzle. I took out the orings between the shroud at the ends and it made a much stiffer barrel connection. I have other guns that use solid CZ barrels and have no shift when pushing on the muzzle end of the barrel. The test was done in my 12 yard basement range so no outside forces played a part. Also just turning the liner in the gun will make the pellets hit in different spots. I marked the top of the liner and shot groups to see where they impacted when clocking the liner at 12/3/6/9 o'clock. The group would move around the POA equally.
 
When one has to install 1, 2 or maybe even 3 barrel bands on a rifle to help minimize POI shifts, I would reasonably determine that barrel cleaning has little or nothing to do with those POI shifts. Mine would have a significant POI shift right after filling the rifle with air. How would that be impacted by a dirty barrel?
Thx
Dan
Was it an Evanix?
I purchased a used Evanix once with 3 barrel bands, depinger, and all sorts of aftermarket items than some D.I.Y.'r thought would improve its accuracy.
It was not accurate at all.
I removed the 3 bands, and it turned out to be a decent shooting (but extremly loud) rifle again.
 
A method I employ when trying to determine if barrel position/movement might be the physical cause of a POI shift is mounting a laser on the barrel then adjusting the laser dot so that it superimposes the crosshairs of the scope, then I torque, twist, bump, carress (🙄), or even stare hard at the barrel and see if the position of the dot changes.😉
 
Last edited:
Unless a company is willing to warranty repair every product with known issue, they will never say publicly that there is a problem. And frankly there is no real solution besides a lot of costly parts to stiffen and secure the liner.
In other words, admitting there is a problem is opening themselves up to a lawsuit. It's a fact of business.


I experienced my POI shifts with a clean barrel. That was one of my steps along the way trying to figure it out. And I will say, it wasn't massive shift, but shooting 1/8" bulls at 30 yards it was noticeable. My Revere has not shown any similar characteristics and it has never had its barrel cleaned since I received it initially and it has shot more pellets. All under same conditions. If Florida is anything, we have pretty consistent weather unless there is a tropical storm/hurricane.
 
I was getting POI shift in a dreamline compact and was able to replicate it by tapping the barrel in 4 locations, up/down/left/right, and the pellet impact would move to the opposide side of where I impacted the muzzle. I took out the orings between the shroud at the ends and it made a much stiffer barrel connection. I have other guns that use solid CZ barrels and have no shift when pushing on the muzzle end of the barrel. The test was done in my 12 yard basement range so no outside forces played a part. Also just turning the liner in the gun will make the pellets hit in different spots. I marked the top of the liner and shot groups to see where they impacted when clocking the liner at 12/3/6/9 o'clock. The group would move around the POA equally.
The rotation of POI with the rotation of liner / barrel is a normal phenomenon and through indexing, the barrel or liner is kept at best position. So it's not an issue.
 
  • Like
Reactions: Vana2 and qball
A method I employ when trying to determine if barrel position might be the physical cause of a POI shift is mounting a laser on the barrel then adjusting the laser dot so that it superimposes the crosshairs of the scope, then I torque, twist, bump, carress (🙄), or even stare hard at the barrel and see if the position of the dot changes.😉
The liner is inside the barrel shell. If the outer barrel shell remains there and liner moves a bit inside the shell, the laser position wouldn't be changed but POI would be changed.
 
The liner is inside the barrel shell. If the outer barrel shell remains there and liner moves a bit inside the shell, the laser position wouldn't be changed but POI would be changed.
I’ve never owned an FX product, but is there any contact point(s) between the barrel and liner/shell? If the barrel is freefloating inside the liner then yes, the laser method wouldn’t help.