100 yard POI Shift

[JW74]

Something that I find happens more than once and a while with my riffles is as follows. I will zero my riffle at 100 yards on a given day and confirm the zero with a 3 shot group before heading home for the day. Then the next time I head to the range with the same ammo and not having cleaned the rifle I find that often my groups with move off center 0.5-0.75" in any given direction. I zero my rifles at an indoor 100 yard range so the wind is not the culprit. Is this normal? Anyone else notice this? Wasn't sure if it was caused by slight changes in temperature, pressure ect.

 

[ShtrRdy]

Do you have different amounts of clothing on?

Or are you using a different shooting position or different front or rear rests?

 

[FearNoWind]

Sure, we've all experienced those kinds of results.
Things to consider include:

Barrel temperature variations
Shooting position (bench - type of seat used, distance from the bench, body position relative to rifle position)
Blood pressure/heart rate/breathing variations
How much coffee ingested immediately prior to the shoot
Clothing differences (bulky vs thin materials)
Whether of nor the parallax adjustment got accidentally moved

 

[JW74]

The shooting position is the same as well as the amount of clothing. This range is indoors so conditions are pretty constant. Parallax is good. I'm sure my breathing and caffeine intake may vary depending on time of day ect.

Also, I shoot off of a bipod with read bag support. Trigger is approx 2.5 lbs (timney).

 

[jgal72]

That happened to me years back. I was using leupold dovetail rings and bases. Found my front ring was lose in base. there metal shavings laying inside my base. Gun always grouped well, but impact changed left and right.

 

[Carman2012]

I used to have that same problem until I started using anti cant levels on my scopes. I laughed at them at first but after seeing how they improved my shooting at longer ranges I have them on all my rifles now. I have also found that since I have been using them my zero has held pretty much dead center sometimes a tad higher but I contribute that to different temperature swings because only ranges I have access to are outdoors.

 

[Rich Coyle]

Something that I find happens more than once and a while with my riffles is as follows. I will zero my riffle at 100 yards on a given day and confirm the zero with a 3 shot group before heading home for the day. Then the next time I head to the range with the same ammo and not having cleaned the rifle I find that often my groups with move off center 0.5-0.75" in any given direction. I zero my rifles at an indoor 100 yard range so the wind is not the culprit. Is this normal? Anyone else notice this? Wasn't sure if it was caused by slight changes in temperature, pressure ect.

As hard as it might be to do, try one shot only each day for five or six days with no change during this test. That will tell you what your hunting first shot is going to do. That is unless your rifle is for targets.

I recently added the level to my rifle also. A real eye opener.

 

[JW74]

The rifle is mainly a steel/target rifle but hunting with it isn't out of the question. As others have mentioned I do have an anti-cant device as well and it is a huge help.

I went out the other day and was able to make a cold bore shot on a 17"x 26" silhouette at 1050 yards.