Lateral group

[cdoc42]

I sighted in my .22-250 at 100 yards with 52gr Sierra Match HP. I fired 5 rounds, and each bullet impacted to the left of the previous round, producing a small "smile."

The first and last bullet holes measured 1.3125 inches from outside edge to outside edge, for a group size of 1.09". The sequential rise to the left from first to last round was 0.3125" (5/16"). Center-to-center the distance between the individual 5 rounds ranged from 0.253 to 0.344 inches.

I then sighted in at 200 yards, with no lateral grouping, and was able to hit a standard empty paint spray can 5 out of 5 shots.

What might have caused the initial lateral group?

[hounddawg]

mechanical problems don't go away by moving the target farther out. I would guess it was shooter error. Most likely parallax caused by a inconsistent cheek weld or canting the rifle


these links may help you pin point the problem

http://www.gunsandammo.com/uncategor...rifle-targets/

https://www.youtube.com/watch?v=Khfr3qC9HKQ

https://www.youtube.com/watch?v=QpOtJuPTsU4

[Ruga Booga]

^^^ agreed

[NoSecondBest]

Possibly some wind velocity change between groups. Even a very small amount of wind can make a difference in POI.

[cdoc42]

Thanks: these two are a strong possibility; with advancing age, I find neck arthritis is causing left upper back muscle pain, interfering with how well I can get my cheek to the stock, so I may well have been canting. I know I started to pay attention to where I placed my finger. When I changed to 200 yards I had to move the front rifle rest to the right and that may have corrected positional problems since the lateral stringing disappeared.

From the first link:

"For right-handed shooters, having your finger too far across the trigger can result in shots stringing to the left."

"As part of your shooting position, watch for canting the rifle. The effects of cant are seen on the target as horizontal stringing"

[hounddawg]

the wind is a good point, it would only take a 10 mph wind to push that little bullet an inch. Mirage can easily shift a target that much also.

I was thinking shooter error because I assume the environmental conditions did not change between the distance change. On the other hand everytime you approach the gun you should have a routine to ensure your body position is the same. Just a slight canting of the gun or shifting of the head can give you a horizontal spread.

Dunno what scope you are running but the 200 dollar department store ones won't show contrast. One day at the range on the way to check targets the other shooters were complaining about the mirage. I was thinking "what mirage ?" When I went downrange I looked at my target and said "Oh that mirage". That scope has been sitting on the shelf since that day

Sorry to get off the subject of reloading, but I doubt your ammo is the problem in this case

[Gary Wells]

22-250 will considerably drift sideways even in a small wind.