Tuning FX Impact MKII questions

[Corvid_hunter]

I'm thinking of buying a .22cal MKII (Power Plenum) with the 700mm barrel and the Superior Liner. I would like to stiffen things up to eliminate the wandering POI. Can this be done by only using the liner sleeve bonded to the liner? If I'm not going to be doing any barrel liner swaps, should I bond both together? Should I also get the barrel sleeve and use both? Can the barrel sleeve be used with the factory shroud? I normally shoot 25gr JSB redesigned pellets, what other ammo is the Superior Liner good with? I live in Canada so a moderator is not allowed. How loud is the MKII shooting ammo in the 950fps range with the 700mm barrel and no moderator? Thanks in advance.

 

[bigHUN]

...I would like to stiffen things up to eliminate the wandering POI...Can this be done by only using the liner sleeve bonded to the liner?...Should I also get the barrel sleeve and use both?...

I normally shoot 25gr JSB redesigned pellets, what other ammo is the Superior Liner good with?

...How loud is the MKII shooting ammo in the 950fps range with the 700mm barrel and no moderator? Thanks in advance.

Me personally I am against to bond the liner to the barrel, if that would do any good I would expect FX to do that at design/production level. They have engineers and R&D and manufacturing process and QC and testing all in house, I would call that setup pretty impressive.

1. I removed the 3x orings between the liner and the barrel tube and let it "free floating" in the barrel tube, and

2. I replaced all the NBR70 soft orings to harder NBR90, all of them which actually "floating" the barrel in the Impact skeleton.

In the FX Impact diagram these are the A6 (2x in the front support block A13, and 2x in the rear support block A7), also the 2x in the barrel kit (A3/B4) which are actually the brass transfer port orings. Also the oring inside shroud rear end towards the gun, this is the A6/B6 that floats the barrel when it is tensioned with a spacer. Do not overtighten the barrel holding screw neither, only fingertight, don't worry won't go anywhere

This shall be good enough for Canadian hot weather over summer, but may make it even stiffer over a winter if you go outdoors.

The other thing is worth to mention...no matter summer or winter, you tune to your own specs in a same temperature condition as you would be scoring, so no tuning in your basement in July/August with AC ON and you just expect that tune will stay when you go outdoors in a mid day to +40C...no matter airgun or archery or just anything.

And I think this were people missing a lot when you hear any winding about POI shifts.

I have the .25 cal 700 liner and shooting 34 grain JSB MK2's at 920 tight I believe that is about 63.9 ft-lbf (86.7 joules), but it was capable for 70 before my mods, have not test it yet after porting.

About a sound @ 900+ ??? It will be laud ;( and you better invest into some decent ear protection, or you figure out.

btw I am in L4G7X4

 

[Glem.Chally]

I would bond the liner and the cf sleeve together, you can remove the conical end on the shroud and get some 20x14 cf that slides under and inside the shroud. Some electrical tape wraps (or something) where the cone goes on the breech end of the shroud works well. (To keep the shroud centered on the muzzle end.) The shroud when its snugged up will really solidify things. 

Make sure the liner lock is always a bit tighter than the shroud onto it or when you remove the shroud you'll pull the liner lock out.

As for sound would be similar to any other airgun shooting at that power in that caliber. Maybe a bit quieter as it has the long barrel.

 

[Corvid_hunter]

Thanks for the replys. I ended up watching some or Ernest Rowe's videos about using the carbon fiber sleeves and bonding them to the barrel. I have a Red Wolf HP and don't think it is all that loud when shooting it on high power. Maybe it's the barrel length.