FX What the shift?

[FoxCrow]

Hi Guys,

I am pretty new to the whole airgun scene, but I did watch a lot of Youtube videos mainly from Matt Dubber, AEAC and some others to prepare for my new toy, a FX Maverick compact in 22 cal topped with a very cheap 4-12x50 scope, and an FX chrono to help me dial it in.

Anyway, I have zeroed the setup at approximately 25 meters at regs 115/85 and powerwheel 4 at 870 fps ->ES of 1 and std dev of 0.5 over 6 shots (for what it is worth) JSB hades .22 15,89gr.
It really shoots like a laser here, ctc group about 3/16 or 5mm. I was very happy with how it performed. So I pushed my target a bit further, 40m this time, expecting the impact to drop a bit vertically, which it did by about 1" or 2,5cm. The only strange thing, it also shifted right by about 2" or 5 cm (I can still print decent groups there., so it is not spread).

So I went online and looked up everything that could cause this to happen, so I started with making sure the optic is level and that the crosshairs are plumb. I spent a whole day using different methods to verify that it was not the optic placement/ adjustment, I used bubble levels, self leveling lasers, plumb bob on a string, light front to back through optic to align crosshair on the wall with a plumb line, I have done just about everything to make sure that the optic and reticle are level and plumb, but still I get the same results.

It is kind of frustrating that I am not able to get it riding the line.
Might it be the cheap optic that might be out of whack?
I am still saving up to get a decent scope, but this is what I have for now.

I am open for suggestions, if possible, an explanation how to check or how to diagnose would be very helpful!

Thanks!

 

[rcarlisle]

If you set up at 10 meters, does it shoot to the left?
Edited to add: When you checked the scope against the plumb line, did you also verify that the vertical crosshair bisects the bore using a mirror? Here is a post with a picture to illustrate:

Plumb Bob for Aligning Scope

I got tired of fooling around with small plumb bob's always moving with the slightest breeze while trying to align my scopes. I machined a large plumb bob out of 2" diameter solid aluminum round bar and that took care of the problem....got all my scopes aligned today and it does make a...

www.airgunnation.com

 

[Vetmx]

Index your liner first. Yes, welcome to owning a FX barrel. You will quickly understand that owning a FX means you are now also responsible for supporting everyone who works in a pellet or slug factory. Indexing my liner fixed it for me once when I had your issue. Another time I had your issue, it was happening at 75 yards but it was with a real barrel. I increased the pellet speed and it went away. How do you index a liner? It seems like you like videos so you should be able to find something.

 

[Gerry52]

Try the regular domed Diabolo 18.13gr pellets too if you haven't already. Almost ALL FX .22's love them. Kinda the gold standard. Some guns don't take to Hades at distance. Luckily for me & my .25 & .30, Hades are the preferred pellet at any distance or situation.

 

[FoxCrow]

Thanks for the answers so far!

Yesterday, I removed the scope + rings from the rifle and set up my self leveling laser so it ran straight down the length of the rifle (middle buttpad, straight through center of HS wheel, over 2 allen bolts that hold the cheekpiece, over center of RIS rail, over center of barrel), with the laser projecting on a wall about 15 yards away. I made sure I mounted the scope dead center as well. So now the laser also ran down the center of the scope.
Next, I looked through the scope, adjusted windage so the vertical crosshair went through the lasers and adjusted the rotation of the scope so the crosshair was now plumb with the laser on the wall. All this while also the rifle remained centered with the laser.

You would say I made sure the optic has been installed level and in line with the bore now, but still I get the same results.

I think Indexing is next. I watched some YT's on it, but what I would like to ask you guys is wether or not to re-install the shroud + moderator (DonnyFL Sumo) after every index?

I did notice there was already an index line on the frontside of the liner, approx at the 7-8 o'clock pos.
Does Anyone know how FX indexes? Do the do 12-3-6-9 (which makes that he liner might have moved from the index), or is it possible they have put it at this position?

Now, my biggest question is, can bad indexing result in a 1"deviation over a distance of 15 meters (zero at 25, and 1" deviation at 40, 40-25=15m)

Thanks!

 

[Scotty1]

As Gerry suggested, try some JSB 18.13 grain pellets. Hades have been known to become inaccurate at distance, in some instances.

 

[Patrick1]

I have a 3 year old Maverick Compact in .22 and installed a graphite composite “stiffener”/sleeve shortly after I received it. It fits snugly over the liner inside of the shroud. Never had an issue with deflection at different shooting distances so……..Maybe this could help?

 

[Kola]

Try different pellet first under the same conditions before you change anything else on the rifle.

If the POI change is consistent across a few different pellet types and brands, then look at the next step.

Do not change two things at any one point in time, change one, test and document, then the next, and so on...

 

[Back_Roads]

A bit of a steady breeze can drift a pellet at the 40 range, just a thought .

 

[FoxCrow]

Thanks again for the additional answers.

So, I did try the 18.13 JSB Jumbo heavies, my rifle likes them well! At 25 I can lob the all through the same hole and at 40 they easily fit on a fingernail.
But still the same issue.

So I indexd the barrel at 25m, I had it print upper right hand at barrel @ 6 o'clock, and far upper left at barrel @ 9 o'clock.
I Indexd the barrel at about 7 o'clock, which printed exactly on the 12 o'clock.
After I set my elevation to match the new indexd POI, I test shot at 25m which were spot on.

Now, when I shot at 40m to verify...... Lo and behold.... Still printing 1"to the right.
No winds, and if everything is correct, level rifle, level scope, scope rifle combo plumb....

I did video the indexing, is it useful for me to share it?

I am kind of running out of ideas....

I did perform everything at 12x zoom.
Is it a possibility this (very cheap) scope might be the issue?

 

[IndyDurtdigger]

Is it a possibility this (very cheap) scope might be the issue?

Yes, and it could be something as mundane as a parallax issue.

 

[rcarlisle]

If you're satisfied the scope is aligned with the bore (I don't see that you've visually verified that the scope is in alignment with the bore using a mirror, but perhaps I missed it), I think the only other thing to cancel out is the scope itself. I assume you do not have a second one to try? As to ammo, it is absolutely worth trying a simple domed pellet. I've not bothered to try the Hades, but I do not like the look of them. The silly impression on the dome is ripe with issues in my opinion. But I also feel if that were the issue, you'd be shotgunning, not grouping in a new location.

 

[FoxCrow]

@rcarlisle Disregard the green laser, I used it to make sure my rifle & sight were plumb

I have used the 18.13gr JSB jumbo heavies to index.

 

[MongooseV8]

All great advice above, the only thing I would add is pellets dont fly straight if they arent happy. The can spiral like a WW2 plane that lost a wing. This can show up as moving poi groups depending on distance. The quality of your tune and air charge can make pellets do some wonky things during flight. I dont think that is your issue since you are shooting at a safe pellet speed, but it is something to consider.

 

[Kola]

Next thing I would do then is to shoot at other distances to see what happens.
Much closer, from 10m out, all the way to 40m and beyond.

I know, as example, on my Dreamline sighted at 50m, if I shoot 75m or more, it moves to the right.
My ballistic calculator also shows drift at the longer ranges, with no wind calculated into the equation, so I assume it to be spin drift.

 

[rickschowengerdt]

There is one thing that you can do to make sure to eliminate the scope. It is called a tall target test. You set the target up with a true vertical line running from top to bottom and make sure to use a level to make sure the vertical line is vertical and also make sure gun is level as well. Then zero the gun at the bottom of the line and shoot a group.
Then what you wind up doing is turning. Your vertical turrets up maybe up to 1 turn. Then reshoot at the same aiming point. at the bottom. If you're group moves to the right, then you either have the scope, not level or the reticle is not square in the scope. Which can happen, I hope this helps.
There are plenty of videos on YT.

 

[Chukar60]

Everything suggested are things you should be or have done with your gun during the tuning Or setting up.
The other thing I would suggest is to use a higher second reg pressure and less hammer.
With a compact you need a very short air burst to prevent pellet wash with excess air. Higher plenum pressure with less hammer is how you achieve that.
Best of luck and Merry Christmas

 

[FoxCrow]

First of all, Merry Christmas and happy holidays!

Thanks again, for all the tips!
I will def. try them!

In the meantime I have dubbelchecked my alignment and levelling, I am quite positive this should all be in check.
Even if there is a small error in here, I dont believe this would result is a 1" shift over 15 meters (16 yards).

For now, I decided to bubble level check my Maverick as a whole, and found some interesting stuff.
I am not sure what it is worth, but let the images speak for themselves and tell me whether or not this should be concering or not:

1. Where front top rail mount, where rail mounts to chassis (top rail removed).

2. Same thing, back side.

3. With rifle still level on top side, measured the chassis underside.

4. Flipped rifle uside down and leveled on trigger guard

5. Now measured at same surface as pic 3.