mk2 Impact liners

 

Hi all I am new to this forum so thanks for letting me join.
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I have a MK2 FX impact .177 and have been having some accuracy issues (inch groups at 30 yards), and on inspecting the liner I have seen what look like tooling marks near the breach end, so I got a replacement STX liner and the replacement looks almost the same, the indentations are just a bit further up the liner. The rifling finishes about 30mm from the breach on one and 40mm on the other. I have looked at a Crown STX liner in .177 and this one has no marks and the rifling goes all the way to the end of the liner, I have put a email in to FX last Tuesday but have had no reply so posting here to see if any one has seen this before or could shed some light on what's going on with FX liners, is it a bad batch ? or have I just been unlucky and got 2 bad ones or are all like it and its not a problem. pics of the 2 liners.
 
I can say you can hardly see where my ST is even twisted at muzzle. Whoever is sending you the STX liners and not looking at them, I’d ask again for a checked out one. 
Your pictures aren’t very clear and I can easily see that circular line is visible and not supposed to see transitions of any marks like that in any barrel.
Luckily you bought it new under warranty or your only option would be cut it off or try lapping. The Mark looks like an indentation. 

I have no idea why as they’re all still twisted from outside. Probably a hardened steel tool rod that’s placed in barrel while it’s twisted. Only way I can imagine it working. 
 
I have no idea why as they’re all still twisted from outside. Probably a hardened steel tool rod that’s placed in barrel while it’s twisted. Only way I can imagine it working.


From some research I've done the principle behind STX technology is not actually new, it's very old and was used in at least one makers black powder rifles long ago but was too expensive to be practical, the rifling is pressed into the barrel from the outside, no twisting of the barrel is done...

The hardened steel rod you refer to is called a mandrel...

This may or may not be entirely accurate information... Take it with a grain of salt as STX tech is proprietary...

Ken
 
It is where the rifling start. You can see on the outside of the liner.

yes it looks like that to me to the rifling starts at different points on the liners and the marks on the inside correspond. if FX ever get back to me i might get an answer or at least someone to check a new liner before they send it out third time lucky !!! not that luck should have anything to do with it.

it's a pellet liner not seen a slug liner but the 3 STX pellet liners i have seen have the rifling down to the end except the 2 i have 😢 

Thanks for all your reply's
 
That looks like a screwed up leade and not the muzzle end but I see no ring around the outside to indicate that is so. Sad to say but I would guess that there is doubtless a bad batch as just two like that are not likely. So, we will probly be seeing more of these in the near future. That gives us something to look for if we have accuracy issues.
 


Hi all I am new to this forum so thanks for letting me join.

I have a MK2 FX impact .177 and have been having some accuracy issues (inch groups at 30 yards), and on inspecting the liner I have seen what look like tooling marks near the breach end, so I got a replacement STX liner and the replacement looks almost the same, the indentations are just a bit further up the liner. The rifling finishes about 30mm from the breach on one and 40mm on the other. I have looked at a Crown STX liner in .177 and this one has no marks and the rifling goes all the way to the end of the liner, I have put a email in to FX last Tuesday but have had no reply so posting here to see if any one has seen this before or could shed some light on what's going on with FX liners, is it a bad batch ? or have I just been unlucky and got 2 bad ones or are all like it and its not a problem. pics of the 2 liners.

Please send an email at [email protected] or PM us as we'll get you out a replacement. Let us know if you're based in the US or in another country. If you're not in the US we can help contact FX Sweden and get you taken care of. We haven't seen tooling marks like that before so not sure what happened, but happy to take care of you and get you a replacement (the joy and ease of the STX liner system makes this a simple fix!)
 
I took my .177 liner out from my impact, and took a picture
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The rifling on my gun ends just before the marking ring. And the rifling starts at the same spot inside the barrel. My gun shoot just fine with this liner.

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Sorry for the bad seccond picture, I could not get my phone to focus properly. But as you can see the rifling starts a few mm inside my liner. It doeas not seem to have the 2 small dumps just before the rifling though. 


 
Obviously a different caliber, but still STX. No such tool marks in the bore. I hope this is interesting/helpful:

https://www.airgunnation.com/topic/smooth-twist-x-borescope/

We do actually see the start of the rifling, just as on the pictures on this thread. On the video we do not see it before he push the pellet in, as the light then gets reflected back from the pellet. Just right before the pellet stop, we see it engage the rifling.
 
I do not know if Jeffman`s liner has a manufacturing fault or not. But his .177 liner is different from mine, if the rifling start 30 mm from the end. The pellet would probably not engange the rifling before it gets shot out of the barrel. Either do I know if it would make any difference regarding accuracy. I would send some pictures to the dealer, and they can find out if it is intended to be like this or not.