Indexing Barrel liners in FX Impact - FX Wildcat

I haven't done any of this yet (I'm on the list for an FX Impact MKII .25), but I wanted to thank everyone for a great thread. I'm hoping that pellet manufacturers can see threads like this and realize the importance of getting the pellet weights more consistent. With less weight variance we'd all shoot better, and who doesn't want that?

wow great thread you all are doing a service to the sport

I just indexed my .22 slug liner using 18 grn JSBs at 50 yards. I numbered the 3 shot groups in order. On the last number 7 group I shot two into one hole then pulled the third shot. So I followed up with a fourth and it went swishhh into the same hole as the first two. I stopped there.

Swish, Thanks for showing the results of your test. Just think, if you had not done this you might have had it at the 3 position for years and thought your gun wasn't very accurate, when after indexing the barrel you see that at the 7 position it is just stacking pellets. These STX barrel liners give us the opportunity to index them very easily and I think everyone should do so. Now make a registration mark on the liner so if you ever take it out you will know where to put it back in.

Yeah, it is pretty awesome to be able to clock the liners. It truly takes the accuracy to another level.

At first I thought, Oh bummer the slug liner doesn't shoot pellets as good as I was hoping. Oh well, that's what the pellet liner is for. Then after clocking it I realized I might have a liner that shoots them both excellent. 

The last couple of weekends I've been shooting pellets out to 200 yards and was amazed how well they stayed together at that range. I figured it was because FX nailed the twist rate needed for long range. It will be interesting to see if the slug liner will have similar results with pellets. 

You have discovered the same thing I did with a friends' new Crown he let me play with, and that's that the slug liners shoot pellets better than the A or B liners do...I tuned his Crown for him to where it shoots the 34 grain JSB MKI pellets through his slug liner at 1015 ft/s...which equals 78 ft/lbs energy! And it shot them like lasers! And you will also discover that the faster you shoot your pellets in the slug liner the more accurate they become! No kidding! 

Swish, just curious as to what your aim point was. I did the test too on my 30cal Crown but I aimed at spot. I was also looking for the highest POI and a the tightest groups. I thought one of the main things was to find the highest POI so that you could minimize left and right straight line travel from your zero. Maybe I misunderstood the process and goals.

Jimmy

Swish, just curious as to what your aim point was. I did the test too on my 30cal Crown but I aimed at spot. I was also looking for the highest POI and a the tightest groups. I thought one of the main things was to find the highest POI so that you could minimize left and right straight line travel from your zero. Maybe I misunderstood the process and goals.

Jimmy

Click to expand...

If you look at the pic, group number 1 has a dot I circled on with a pen. That was my aim point. I numbered the groups in order.

Jimmy, it's really very simple. On a 50 yard target, make a dot for your point of aim, and use that same dot for your point of aim each time you index the liner to a new position. Then make a registration mark top dead center at the 12 position on the barrel liner, and shoot a 5-shot group at the dot on the cardboard. Then rotate the liner to the 2 o'clock position and shoot a 5-shot group using that same dot for your point of aim, and then rotate the liner to the 4, 6, 8, and 10 o'clock positions and fire five shots at that same dot. You will be surprised to see groups forming on the target all over the place, but steadfastly hold the same point of aim for all groups. You are just looking for the best group and don't care where it forms on the target at this point.

One of those 5 shot groups is going to have every shot in the same hole. This is the point where you will want to set your liner permanently and make a note of where you set it for future reference, so that should you ever remove it you will know where to put it back. Then at that point just re-zero your scope so that your pellets POA = POI and your done. All you're doing is finding out the position in which the liner will put all five shots in the same hole, for absolute best accuracy and from there you can adjust your scope accordingly.

One of those positions may put five shots in a 2-inch group, whereas one of those positions may put all five shots in the same hole! So there you go.

yes my compact cat was like that also did the same thing rotate the liner and shoot till its was best I could get I got a crown coming today so ill be playing with it some if I'm up to it 

This is fascinating and very useful on it's face. Nice work by all. But I wonder what the mechanism of the change actually is and can it relate to other systems? Is it a change in harmonics? Is it related to the quality of the crown in some way? In any event, they shoot better and that is the bottom line. Just curious.

Hi All.

I was reading this thread with interest.

I own a FX Crown in .177 and it is shooting great at low speed but at higher pellet speed it is very sensible for everything.

I decided to try indexing the barrel.

First i removed the barrel and cleaned it to mint condition.

Then I started to shoot in 12, 3 , 6 and 9 possition. It was a rather large circle with a diameter of 6" in around 15 yards.

I then found that the top would be around 1:30 and lowest would be 7:30.

I could see at 1:30 there were some spread - same as on 9 and 2 oclock.

But at 7:30 the pellets went through the same hole.

I Followed the guidance and installed the barrel liner at Highest position 1:30 and tested on different speeds and at 45 yards.

It was shooting bad - not grouping at all. - On lowest energy (12-13 Fpe) it was still fine but on (20 Fpe) very bad.

Then I reindexed the barrel liner to lowest position 7:30 and now it was shooting low and dead accurate. 

So Indexing helped but not with highes position, for me it was lowest position that worked well.

Best regards from Denmark

Claus Olsen

how i can find 12 or 6 clock on barrel?

@PaniSd, Chuck

Thank you both for sharing your valuable information and experience on barrel indexing.

I did the testings myself and learned a lot about this topic.

Feel free to watch my video with my testings.

Cheers and Merry Christmas to you all!

https://www.youtube.com/watch?v=rm8YplyNw_Q

@PaniSd. thank you very much for posting your video in the first place. I sure learned a lot by following your direction and Chuck's advice. This forum is great for us to share and learn new things every day. Cheers.

I simply put a index mark on my STX liner and make sure it’s facing up when installing and this keeps the POI from shifting all over the place.