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.

Pglasgow

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.

Roskoe

Just to add to your thoughts, Phil . . . . there are also certain muzzleloader bullets that just don't fly well at long range - even under calm conditions. The 200 yard group might be five times as big as the 100 yard group.

Others are very good. Like the 250 and 300 gr. Shockwave. If I get a 1.5" group at 100 yards, I usually get a 3 to 4" group at 200 yards.

Pglasgow

Hey Roskoe,

The shockwaves are excellent fliers. It occurs to me that I experience more effects from wind than others do because of the projectiles I generally shoot and the charges I propel them with. Lately I've been shooting 80 grains 3f Goex and the 270 ballet. If cross winds fluctuate by more than 2 mph, its impossible to print an MOA group at 80 yards except by pointing in error enough (by chance) to compensate the windage effects. At a 140 yards, a 6 mph crosswind can move the POI off the target.

The faster the muzzle velocity and the greaterthe projectileballistic efficiency, the less windage affects group size and POI. I think your success, in part (and in addition to your excellent marksmanship), at 200 yards is at least partially a consequence of the good ballistic properties of the bullets you choose and the relatively high velocities (2000+ fps) they are propelled to.

outdoorslover

I would honestly blame it on your shooting above everything else. I could probably only get like 6 inch groups at 150 yards. Are you shooting with open sights??? It could be a hundred different things but I would say it's the shooter.

cayugad

Cross winds can play havoc with long distance. If there was a bad cross wind, you probably have your reason, or at second best, an excuse.

Unless you are a consistent long distance shooter, a distance like that can be intimidating to say the least. Many of use push enough bullets at 100 yards to feel very comfortable. I remember the first time I shot at 150 yards, I put them in a white paper plate, and was pleased with myself. I knew the rifle could do better so there was only one person to blame.

I found with additional range sessions at longer distances I became more used to the scope placement, and sight picture and the groups tightened up eventually. I am sure the same will happen to you. Your shooting a great bullet and an excellent powder charge. I'd guess it was a bad day on the range at long distance is all. Happens to me all the time.

lemoyne

100 gr of what? are the groups round, vertical, or horizontal.
I never could get the dead centers to shoot decent at long rang I think they are deforming at anything over 1500 fps. Study your groups and tell us what you are getting it might indicate what is wrong. Lee

Pglasgow

I've got no reason to believe its the shooter. I am reminded of a 164 yard target recently posted here. The guy seemed apologetic about his wide but very narrow in elevation 5 or 6 shot grouping. It was immediately clear to me, though, that he was a remarkable marksman. Less than .75 MOA in elevation which describes accurately his aiming precision which was sharpshooter quality. He described the range conditions as windy and as little as 4 mph fluctuation would have accounted for all of the windage distribution of the grouping.

It was also clear to me that his sights were WAY off. And he did say that he adjusted his sight's windage to keep the shot on the bull. Wind is very important in muzzleloading at the extreme ranges.

cayugad

It will be interesting to see what his next range experience is. The projectile he shoots work excellent for me out of two of my inlines. They are kind of the go to load when other loads fail and I want to check the rifle.

bowbender6

Thanks _ for the input - I'll keep trying and looking for a pattern. I have a 4-12x swift with adjustable parallax error on my Omegashooting off a lead sled off a concrete wall. The crosshairs are not moving when I squeeze.

Shooting yesterday - very little wind and most of the bullet path is cover by brush or spruce trees.

150yrds.
Shooting 195 gr Duplex dead center
100gr T7FF

I have RSI shooting computer program to analyze target results.
Here are the results:
Max Spread 3.51
Vert Spread 1.67
Horz. Spread 3.38

I also shot every other shot at 90 Yards. And put every shot inside 1.5” group.

Maybe there is more wind than I think- even though I can’t feel it. Maybe I am getting to picky.