Indexing Barrel liners in FX Impact - FX Wildcat

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PaniSd

PaniSd

Member
Dec 4, 2018
79
12
Serbia
Hi guys

I have searched internet and forums regarding this topic and I didn’t find any specific information regarding FX liner system. What I mean is the every time I take out liner insert (barrel) the POI has been shifted and you need to sight in your scope again.

This finding has forced me to test barrel liners in FX Wildcat and FX Impact since it must be better way to do this. I want to change barrel liners, or just to take it out clean put it back without shifting POI.

Also, accuracy change after barrel liner was out and put back again. Im saying that for example before barrel liner I took out my average groups ware 1’’ or little bit more on 100m. After reinstalling barrel, sight in again and I could not accomplish this score never again.

So, there are 2 things that I have find out during tests I made and they are:

1. POI shifts every time you take barrel liner out

2. Influence of projectile trajectory … accuracy

At the end I successfully find solution for my problems with indexing (rotating) the barrel and finding best position for barrel liner what did improve my accuracy very-very-very much guys.I have tested 2 guns, FX Wildcat mk2 .25 600mm barrel and FX Impact X in .22 stx liner and liner type B and .25 stx liner. With all of the setups same problem occurred and at the end all worked well. My findings have helped people in my surrounding fixing the problem and improve accuracy.

Strange thing is that nobody talks about it and I’m 100% sure other people have same issue as I do.

Fill free to comment, bring your experience with it and I hope the video I made will help many people, and guys … video is not the best one, it’s my first ever video I made so don’t be hard on me J J J but main point is that throe this video you will get an idea what I did and you can do the same by yourself. You don’t need to go to service or send your airgun to fix it and most important part is you are doing nothing what will influence on your warranty.

Maybe this way is not the best one, maybe some people find better solution for this ... but it did work perfectly for my 2 guns and some people to.

Enjoy video and let me know your impressions.

https://youtu.be/w5ssxp6tqvs
 
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Yes taking the liner out will change poi and you will have to rezero. But you do not need to take the liner out to clean. You can easily clean the barrel by taking the barrel kit out. Taking the whole barrel kit out and putting it back in does not change poi. When I clean the barrel, I take the LDC off then run a 80 lb fishing line through and put a wet clothes and pull it out. Repeat, till it's clean. 
 
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Yes … that’s how I do it also now.

But there is another thing in test and that’s accuracy and the pellet flight direction with different barrel liner position. Getting the straight path of projectile is crucial to improve accuracy …

Straight from FX factory my Fx Impact .25 in 600mm was totally out of precision … 50m 2’’ group so I had to do this kind of indexing and manage to get under ½’’ groups easily.
 
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Certainly an interesting concept. I recall reading an article many many years ago about testing barrels to see if they had a preferred "plane of vibration" so that they could be indexed to that plane. Never saw any follow up to that but it seems to relate to the concept mentioned here other than the fixed/screwed on muzzle end for these liner systems. Interested to see further results.
 
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Not a FX anything.

But, this barrel is going into a gun to be able to rotate for the best index location for the same reason. 

I read a long in-depth article about indexing a couple years ago. Looked hard for it since. Can't find it now. 

1553011716_19304949615c9114045adea4.54343668_IMG_6119_2.jpg


Impressed me enough to come up with a pain in the ass design for the ability to rotate my barrel.......
 
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PaniSD - That video really shows the difference a lot better than an in-depth article about indexing can. 

As you test some groups may be tighter than others. It's the highest and lowest groups (12:00 high & 6:00 low) that are usually the tightest. 

I'm curious if you find that some groups open up more as you rotate the liner. 

I'll bet a 45 degree rotation for 8 groups @ 50 yards indoors with a gun vise and a remote trigger pull devise would show what you discovered even more dramatic than the 4 groups you did. 8 or more positions makes it easier to see the egg shaped pattern for selecting the true 12:00 or 6:00 positions. 

You may have already helped one person here so far with this post. 

Be interesting to see what you find......








 
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Long_Shot

Thanks bro, I appreciate your comments and open way of thinking regarding this subject.

As I said before, the only reason I made this video is that almost a year ago I have discover this and waiting to see will somebody else mention it and conform my findings.

Due so limited info about this subject I had to find my own way to do this, is there better ways … yes I agree and I will definitely try to improve way of presenting and testing.

First of all, I will not make this video if I’m not 100% sure in what I’m doing and the results. So far 3 different guns with accuracy issue ware fixed this way and some more improve accuracy.

I’m not video maker pro, pure amateur I’m … but I enjoyed creating something that I can share and that will help my fellow air gunners.

When I have time, I will proceed to a next step of barrel fine tuning and some other findings that come up along the way but this will be subject in next topic.

Thanks again for your support and let’s keep on discussing since who know how many good ideas may come up from it.
 
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PaniSD,

Thanks for bringing this up again. It got me to thinking about my 30cal Crown and how's its currently set up. It's very accurate as is but if I can squeak out a little more I'm all for it. I performed the test this morning at 60yds. I shot 3 pellet groups at four different targets, rotating the liner 90 degrees each time. I also marked the air stripper and the liner retention nut to ensure I got ever think to the same point on every liner rotation. I had a pesky 3-5mph wind but around here that's as good as it gets first thing in the mornings. I was shooting weight sorted and lubed JSB 44.75's off a cement bench with a bi-pod on the front and a bag on the back.

1553446446_7149621575c97b62e2ff955.69299536_IMG_3051.jpg


My groups were pretty good through out the test but I hoping for better long range accuracy knowing that at least my pellets are heading to the left or right. I found my max height after turning the liner 180 degrees.

1553446582_6746442125c97b6b6f3ee23.78075416_IMG_3049.jpg


I shot one more group to confirm my 180degree finding and it was a good repeat of the #3 group.

1553446717_20555088075c97b73d5040f7.27929155_IMG_3050.jpg


I know I didn't do any harm and hopefully it'll help with longer distance accuracy.

Thanks again for bringing this to light.

Jking


 
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