ORIGINAL: bowbender6
I have a TC omega shoots 1" - 2" groups at 100 yrds with 100gr and Barnes 250 PBT and PR Bullet 195 gr duplex dead center. The problem is at 150 yrds the groups are about 6". Seems like they are opening up a lot more than they should. Any ideas or similar experiences? Even with very little wind.
Bowbender
Group size MOAincreases with range. For a number of reasons. With wind the effects of the wind accumulate. With bullet instability, the effects are also cumulative with time. Given no wind and perfect bullet stability, the MOA at 100 yards would be your pointing precision (literally a measure of your pointing (or aiming) uncertainty. Again given perfect bullet stability and no wind, the MOA at 150 yards would be identicalfrom 1.5" to 3".
Patterns will help to tell you where the uncertainties lie, whether pointing, wind, or bullet stability. Lets say you have groups which are wide but very narrow in the vertical axis (say no more than 1/2 inch above or below a horizontal line passing through the center of the grouping), then it is likely that wind is the cause of the horizontal spreading of the group. This grouping at 100 yards indicates that the combined pointing and bullet stability uncertainties are less than MOA. Do that at 150 yards, you a quite a marksman.
To get a good idea of bullet stability uncertainty, one must have absolutely pristine range conditions and see how MOA grows with the range of the target. It is best done with machine rested rifle.
Alot of people don't understand the effects of wind on precision. If your group size is caused primarily by wind (narrow vertical, wide horizontal), then you are learning just how precarious long range shooting can be with slow moving projectiles of low ballistic efficiency. I have a feeling that you are shooting better than you think you are, but I would need to know more about range conditions and the group size charateristics toknow for sure.