Sighting in Frustration

[FelixS]

I usually shoot with JSB Kings and was sighted in at 50 yards. I have been using the holdover method for longer ranges, up to 100 yards.

Yesterday, I decided to try the JSB MKIIs and since the POI is different from the Kings, I decided to mark the adjustment with a sticker.

I proceeded to sight in at 50, 70 80 and 100 yards with the MKIIs. I did the same with the Kings using a different color sticker.

I then switched from the Kings to the MKIIs at different ranges - absolutely fantastic results! Why didn't I do this before, I thought.

Then today, I started with the Kings. Off .25 MOA at 50 yards, off 1.5 MOA at 70 yards, off 2 MOA at 80 yards. My reg pressure was stable at 2,000 psi. The temperature was about the same on both days, in the low 40's f. The difference is that today is a rainy day, but it wasn't raining at the time I took the shots.

Is this the cause, humidity? Does it make that much of a difference?

 

[Kaeokini]

Aloha FelixS,

what fps are you shooting with the kings vs. the mk2? how dirty is the barrel? Is the POI .25 low, high, left, or right?

the only reason I ask these questions is that when I tried the same thing you were doing is that I tuned my gun to shoot mk1 and when I tried to shoot kings, I had high groups and some fliers because they were going to fast, when I turned down the fps for the kings I got my accuracy back.

Aloha, Keone

 

[FelixS]

Thanks, Keone. The POIs are all low. FPS for the Kings are 920 average. I didn't check the MKII fps.

Although cleaning came to mind, I didn't consider cleaning the barrel as the fix because it was spot on yesterday.

The mystery is, why are things so different today? I actually didn't get to shooting till late in the day so did not even try the MKIIs.

I'm shooting with a Bobcat and know nothing about adjusting the reg. I'll do some checking.

Thanks, again.

 

[Redick]

Could your scope rings be loose? Check to see if all bolts are tight. 

 

[bubblerboy64]

I find this to be a common occurrence. Not just with air rifles. The only constant is change and it doesn’t take much. Light, wind and then possibly something with the gun or scope

 

[BarryW]

I had a similar problem with my raw hm1000x. 25cal. After much frustration, I came here to AGN for help. My fix ended up being the scope rings were over tightened. After I torqued the rings properly my poi settled and it stays consistent from day to day now. Thank you AGN!!! Barry

 

[FelixS]

The Bobcat had previously been performing very consistently, accurate, and never presented any issues. In response to all of your tips and information, I just went out to the garage to check the scope, that's when I realized a change that I did not take into consideration. I just got a side-shot phone camera mount and the videos were all upside down, which is very annoying. So I found that you can fix the mount on the opposite side and the videos come out right side up. I also adjusted the focus for a better picture. I think that's it - user error!

I won't be able to shoot till Saturday, but will test my theory, I think that is the problem.

Thanks to everyone for your input and tips. I don't know that I would have even thought of this without your help!