FX FX guns WITHOUT POI Shift Issues

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Ghostranger169

Ghostranger169

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Jun 9, 2019
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Lamont, FL, United States
Seems like there are a lot of threads about POI issues in general, esp FX guns. Does anyone else have any FX guns that DON'T have POI issues?
I have owned these three FX Crown MK2s(set up in the configurations seen here) for over 2 years and consider them "stable" with respect to POI shift. After years of tuning/experimenting my 1st Crown MK 1, I found commonalities in what "works for me" with regards to reg pressure, HS tension, projectile weights/speeds, carbon fiber sleeve, cleaning regimen, moderator(type/weight/exit hole size) etc... to "settle the gun in" to be consistent(or what I refer to as "stable"). I store them sitting on shelves(as seen in pics) or in their case. At the very least, I have shot each of them once a month(at the test targets shown here) without having to "adjust" anything. 2 of the 3 have the AMP reg, one has been changed to Huma. No creep or leaks.
1st- .22 Crown MK2 with 300mm Dreamline barrel and Huma Mod30 shooting JSB 18g @ 850 fps
2nd- .22 Crown MK2 in Saber Tactical Chassis with 380mm and DFL Shogun shooting H&N 21g slugs @ 856 fps
3rd- .22 Crown MK2 in ST Chassis with 700mm and DFL Tanto shooting JSB KO mk2s @938 fps
All have non-epoxied carbon fiber sleeves and one spacer toward the muzzle end.

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Dreamline, superior 600mm 25, superior 22 600, an. 25 superior 380mm, Crown continuum in 22. What do you mean "poi shifts'. Different velocity, pressures, dwells, its going to change the air flow. So of course the poi can change a bit. But once set the poi is so consistent and tight that when my groups are more than one hole anywhere shy of 60m I feel something wrong has happened. Tuning is about getting your best harmonic balance. Giving your best grouping and most consistent velocities for the given projectile and desired power.


If you're talking about shifts between projectiles... Yeah , of course .

Are you shooting in the wind? Explain what you mean

Edit: "does anyone else"...

Yes I have FX guns that are lights out and the POI doesn't shift unless I change something.
 
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$p00kygH0ST said:
Dreamline, superior 600mm 25, superior 22 600, an. 25 superior 380mm, Crown continuum in 22. What do you mean "poi shifts'. Different velocity, pressures, dwells, its going to change the air flow. So of course the poi can change a bit. But once set the poi is so consistent and tight that when my groups are more than one hole anywhere shy of 60m I feel something wrong has happened. Tuning is about getting your best harmonic balance. Giving your best grouping and most consistent velocities for the given projectile and desired power.


If you're talking about shifts between projectiles... Yeah , of course .

Are you shooting in the wind? Explain what you mean

Edit: "does anyone else"...

Yes I have FX guns that are lights out and the POI doesn't shift unless I change something
Click to expand...
$p00kygH0ST said:
Dreamline, superior 600mm 25, superior 22 600, an. 25 superior 380mm, Crown continuum in 22. What do you mean "poi shifts'. Different velocity, pressures, dwells, its going to change the air flow. So of course the poi can change a bit. But once set the poi is so consistent and tight that when my groups are more than one hole anywhere shy of 60m I feel something wrong has happened. Tuning is about getting your best harmonic balance. Giving your best grouping and most consistent velocities for the given projectile and desired power.


If you're talking about shifts between projectiles... Yeah , of course .

Are you shooting in the wind? Explain what you mean

Edit: "does anyone else"...

Yes I have FX guns that are lights out and the POI doesn't shift unless I change something.
Click to expand...
The Point Of Impact of whatever projectile(pellet or slug) has shifted away from where you are aiming(as if you had changed your scope turrents) WITHOUT any discernible cause(like wind, changing power levels, etc...)
Enter "POI shift" in the search bar. You will get a myriad of threads on this topic. Click on a couple of them to bring you up to speed.
 
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I have mk2 Impact.
No poi shift or regulator creep.
600 mm 30 cal and 600 mm 22 cal.
Also no poi shifts with my Dreamline.

Had 3 Streamlines and 2 Royale which were rock solid also on one Streamline i didn't made 1 click on the scope for three years and always spot on.
I bellive most of poi shift that people experiece is made by bad tune or something in the barrel system not tight or o rings on the liner moving.
1 thing to mention,i never lean rifles on the barrel or throw them around.

Regards Marko
 
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Ghostranger169 said:
The Point Of Impact of whatever projectile(pellet or slug) has shifted away from where you are aiming(as if you had changed your scope turrents) WITHOUT any discernible cause(like wind, changing power levels, etc...)
Enter "POI shift" in the search bar. You will get a myriad of threads on this topic. Click on a couple of them to bring you up to speed.
Click to expand...
Yes I know what the damn term means. I didn't see where you specified it happened during the same session. And no. Never. Usually it's something small. A mildly loose bolt on one scope ring or the rail, lose mod, failing breech oring, shroud loosened... Other than first shot after moving outside. Because I tune indoor the velocity will drop because the plenum pressure rises a bit from 68⁰ to 95⁰. For 1 shot..
I've always found accuracy issues to be something mechanical. Usually something simple. Do you use soft cases or hard cases? Do you lean your guns?

I zero for 35 yards to be my zero point. But I shoot it 60yards usually. Once I stopped zeroing at 25 and 30 all issues ceased. Ballistics app and reality are one now. Always on.
 
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$p00kygH0ST said:
I found removing barrel band off my dreamline improved things.
Click to expand...
I found I was too hard on my rifles and every time I would pick it up by the barrel or bang it against something it would move poi so I put Barrel bands on and have not had issues since, I carry my rifles slung barrel down and they have 700 mm barrels so they are going to bang on logs and downed Limbs while walking through Timber
 
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SilentSquirrel said:
None of mine have the disease
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Nor does my M3.
I've posted it before, in MY case I'm not pushing the envelope power wise with mine. It's shooting 34 grain pellets out of my 700 mm barrel just fine at 915 fps with a 2nd reg set at 108, hammer at just under 4. Day in day out, no shooting for a week, etc. It's a dream.
 
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I understand that many of you FX owners are not engineers, but there is no excuse for not understanding this POI issue. Some of you have this issue and some do not. The difference is the way the barrel mounts to the receiver. The scope mounts to the receiver, not the barrel. The receiver has a bored hole in it that the barrel slips into. The barrel is indexed to align the air port and it is held in place by simple set screws. The POI issue is caused because the fit on some guns is too loose. There must always be some clearance so the barrel slips into the bore, so it can never be zero. There is no reference surface for the barrel to clamp against and in so doing can shift a bit throwing off the POI even with the slightest bump.
 
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steve-l said:
I understand that many of you FX owners are not engineers, but there is no excuse for not understanding this POI issue. Some of you have this issue and some do not. The difference is the way the barrel mounts to the receiver. The scope mounts to the receiver, not the barrel. The receiver has a bored hole in it that the barrel slips into. The barrel is indexed to align the air port and it is held in place by simple set screws. The POI issue is caused because the fit on some guns is too loose. There must always be some clearance so the barrel slips into the bore, so it can never be zero. There is no reference surface for the barrel to clamp against and in so doing can shift a bit throwing off the POI even with the slightest bump.
Click to expand...
Yes, POI can be shifted by this happening(bumping/pushing barrel) because of set screw attachment system(good for quick/easy barrel switchouts, but not so good for durability/impact resistance), but POI can be shifted in other ways, like by the liner spacers within the shroud moving. Which is what I experienced with these 3 guns, fairly soon after I began to "push" them to get more power to shoot slugs and/or use shorter barrels:

FX spacers are "friction fit" pieces of plastic with o-rings "connecting" the liner to the shroud(at various points) down the length out to the muzzle. The air(and lead particles) from inside the liner is re-directed backward(toward the action) into the shroud from the muzzle end. There is a tiny hole near the action end of the shroud which vents some of the air(and lead particles).
The more air that is forced backward into the shroud(i.e- the faster/more power you shoot), the more(and higher pressure) air(and lead particles) is forced backward into the shroud. This redirected, high pressure air "blasts" into the shroud, impacting the spacers. Over time, this increases the likelyhood that the "friction fit" on the spacers will give way, and they will move to a different point of contact on the liner/shroud. This new contact point can potentially change harmonics, POI, etc...
At lower power, this system seems to stay in place well. When the power is increased to near max settings, no so much. The solution that has yielded the most consistency for me is using the carbon fiber sleeve over the liner. This serves help to stiffen the liner/shroud and anchors a single front spacer near the muzzle. It also makes it easier to remove the shroud for cleaning the barrel and cleaning the lead dust out of the shroud/liner system(which should be done on a regular basis because it actually does improve performance).
 
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dens228 said:
Nor does my M3.
I've posted it before, in MY case I'm not pushing the envelope power wise with mine. It's shooting 34 grain pellets out of my 700 mm barrel just fine at 915 fps with a 2nd reg set at 108, hammer at just under 4. Day in day out, no shooting for a week, etc. It's a dream.
Click to expand...
I don't think I am maxed out on my wildcat/maverick,it's sending 45.5gr. Slugs at 940 fps with 2nd reg.at 125. My other wildcat moved poi every time I looked at it,so tried barrel band and haven't had issues since. When I received my new m3, I didn't give it a chance and immediately put a barrel band on. I hate a gun that won't hold zero.
 
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