Left to Right shift based on distance

Jump to latest Follow Reply
Smitty911

Smitty911

Member
Aug 4, 2018
703
494
Orangeburg, SC, United States
I have three PCP, Brocock Bantam (.25 cal, unregulated), Brocock Sniper XR (.25 Cal) and Daystate Redwolf (.22 HP). The Bantam I have maybe a 150 pellets through it - not enough to really get to "know" her. The Sniper, I just got her, so maybe 100 pellets (1 was dedicated to dispatching a rat :) Full Disclosure - 2 where shot at the rat), and my Redwolf less than 100.
I seem to notice shooting the Sniper and Bantam that the POI shifts. Example: The Sniper last weekend, I zero'd at 50 yards. 10 shots all in 1". Yes, I need to work on my shooting skills. When I was shooting at 25 yard, the POI was slightly to the left of the target and at 75 yards it was slightly to the right. Little to no wind, 72ºF, sunny.

Am I nuts? I'll take them out this weekend and shoot the above and get actual measurement's.
If it continues to happen, what are the fixes? I get that there will be a POI with distance in the Z axis, but in the X Axis?

Smitty
 
Throwing curves.. seemed like thetes some slow mo air gun vids wirh tracer pellets you can see that in them.

Pellet weight , shape , and all that jazz could be curving and mote stright line.

Then your eyes . Could be a parellix thing.. its like i shoot zeroed with both eyes open then i shoot one eye closed the poi can shift. i found that to be near the center of the bridge of my nose to the center of the open eye at ranges .

Some cante a bit as the distance goes out . Not noticable and close we range bit as you ho further out it starts to increase and shows more and more.

Also a scope not true level with the barrel. You may see nice stright ip and down at 10-20 yards when clicking but at 100y you may see a slight diagonal.

One of my saying is a fraction of a 1/10mm at the muzzle can equila a 1" down range. The more you go out the more it shows.

( Disclaimer.... Im no expert but i portray one in forums)
 
Upvote 0
As stated above, it is likely a scope mounting issue. But that said, I have had rifles that, for some unknown reason would display a left or right POI shift at different distances. It was never a significant amount, but I never understood it. You can test for the scope thing easily, regardless of how it's mounted. Draw a horizontal line on the paper using a level. Then align the elevation cross hair on that line, and shoot at different distances. If the scope was not mounted perfectly, you will need to cant the rifle slightly to align the cross hair. If you then notice the POI change is strictly a vertical variance, then the scope mounting, or your hold, is the cause. If that doesn't correct it, then you have one of those mystery rifles.
 
Upvote 0
Smitty911 said:
Thanks, I've been shooting them as they came mounted form AoA. I was worried it was a barrel thing and not the scope.

Live and learn, or don't :ROFLMAO:

Smitty
Click to expand...
For all you know that guy could of been a cockeyed 1/2 blind coke bottle bottom glasses wearing with a creek in his neck and pulled off and he street hired at min wage when it was mounted...lol ( kinda like me🤔)
 
Upvote 0
You said that you zeroed the gun in “little to no wind” at 50yds. Even a “little” wind can make a slight difference. If that was a little left to right wind, then you should be hitting slightly to the left at 25yds and slightly to the right at 75yds. That is what you said was happening. So there may not really be anything wrong with your setup.

To verify scope mount settings, zero it at 25yds and then check it at 10yds. That will minimize the wind related poa/poi variations and maximize the scope cant related poa/poi shifts.
 
  • Like
Reactions: Chuck-in-Ohio
Upvote 0
Scotchmo said:
You said that you zeroed the gun in “little to no wind” at 50yds. Even a “little” wind can make a slight difference. If that was a little left to right wind, then you should be hitting slightly to the left at 25yds and slightly to the right at 75yds. That is what you said was happening. So there may not really be anything wrong with your setup.

To verify scope mount settings, zero it at 25yds and then check it at 10yds. That will minimize the wind related poa/poi variations and maximize the scope cant related poa/poi shifts.
Click to expand...
Scotchmo,
Thanks, The wind were I shoot is normally in my face. I start shooting around 0730 so there really isn't much wind to worry about.
I'll set up a couple of targets and walk it out. Thank God for Laser Range Finders.

Smitty
 
Upvote 0
Smitty911 said:
Scotchmo,
Thanks, The wind were I shoot is normally in my face. I start shooting around 0730 so there really isn't much wind to worry about.
I'll set up a couple of targets and walk it out. Thank God for Laser Range Finders.

Smitty
Click to expand...
How much is "really isnt much wind to worry about" My impact in .22 shoots JSB 18 gr. pellets at 990 fps. At 50 yds a 1 mph crosswind moves the pellet .200. Thats not very much but thats almost a quarter inch for just 1 mph cross wind. My BSA R10 mk2 shoots the same pellet at 860 fps and the 1 mph crosswind moves it .300 at 50 yds. Pellets are effected by anything thats not dead calm so theres no such thing as not enough wind to worry about when talking pellet's at 50 yds or more. So if you zero a rifle at 50 yds in anything other than dead calm your zero is being effected and could be off by the amount I gave in my examples or more if it was a 2 mph crosswind.
 
Upvote 0
Ranchibi said:
Also, the guns are quite new, give them time to settle (regs) and the barrel to season. The scope cant you'll fix easily!
Click to expand...
Ya, new .. you kinda got to give it time to settle in, break in . When i get new outside physical damage or just awful its more or less get 4 tins of 500 count crosmans (for example) and shoot, shoot , shoot.. things tend to fall into place or get worse or broken defective part show up and then like new clearly bad it's rma time. Every 250 shots id do a good go over like clean barrel well, nuts , bolts ,screws check / make sure alls in there proper place and tight.. then on top of that sholdering the new gun is more natural to its feel and use. By then normally it's time drop some dimes...lol


Good luck and enjoy
 
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu