Fx impact mk2 25 cal 700mm zeroing

Hello everyone, I'm new here but I would like to see if anyone else is having issues with their impact. I have mine zeroed at 50 yards and was shooting 100 with a hold of 12 moa. I recently installed the CF liner and now I'm having to hold over 16 moa at 100. I did the barrel indexing and is still having to hold at 16 moa at 100. Any idea as to why the big drop?

Mod edit: moved to PCP section
 
More than likely because you indexed you liner. I indexed mine too and at 30 yards I was like 4 inches low when 30 was zero for me. If you didn’t change nothing else beside the carbon liner and indexing your barrel, your poi issue is one for those 2. If you have adjustable rings go back to 50 yards check your zero. And adjust the scope to the impact point. Should solve your issue. 
 
The way indexing was explained to me, one of my buddies shoot long range powder burners. Said no barrel is perfectly straight they all have a “bend” to them. So gunsmiths will find the highest point of the barrel or to where the bend is at the top so when you shoot and the barrel gets hot it becomes straight. So with the liners same concept with the bend to the top you will be shooting lower but your projectile will fly straighter. You will have that nice arch. Hope this helps. 
 
It was just weird cus after tuning and before I installed the liner, I was holding 12 moa at 100 just like the hawkechair app is suggesting. After the liner installed, I'm hold at 16 not 12. Was thinking of putting the o-rings back on and see if it goes back?

I’d almost bet it’s from indexing your liner. Check 0 at 50 yards I can almost bet you will be off there too. The carbon sleeve is way more bette than the oring. I made the mistake of not marking my liner before pulling it before I indexed it and my shot was way way off. 
 
Yes, you may did the indexing right and you got the groups rotate around some imaginary center point, but where did you put the index? 12 a clock or 3 or maybe 4.5?

Me personally I did the indexing @ 100 meters and I put my chosen index somewhere in between 1 a clock and 2, because that group was a closest to optical center to my scope and that group was average not the best and not the worst....

Other ppl most likely doing in different way.
 
When changing the liner I did forget to mark the barrel but was off right off the back when I was trying to group them. I re-rezoed at 50 and moa changed at 100. Got home marked my barrel went out and indexed my barrel to the highest point which was at about 1 o'clock where I marked it and was still shooting at a 16 moa. Might go out in the next couple of days and re index the barrel to see if poi changes. 
 
Maybe you torqued the nut that holds the liner in the sleevewith more or less force than before ,and the liner "bends" in the sleeve different than before???creating a difference in change of trajectory?

I'll second what Julez said. I didn't think I had tightened the nut down too snug, but when I backed it off and torqued it back down slightly less my issue went away.
 
Figured it out guys. It was the transfer port. When taking out the whole assembly to clean while putting on the CF liner, I put it back in with the small hole on the bottom. Which resulted with a lower fps and dropping my moa. Sad but could of figured it out yesterday but left my chronograph on and battery went dead so I couldn't get a read. Will go out tomorrow to re index my barrel and test out the difference. Will let you guys know how it turns out. Thanks for all the input.
 
Hey guys. So I flipped the transfer port and re indexed my barrel. It solved my issues. Shooting straight and holding accurate. Now time to start tuning some more.
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