I had set up a 5'X 8' paper target a 600 yds to check bullet drop with my 7mmSTW. I was shooting 150gr. sierra BT's. First, I fired 3 rounds @100 yards to check my zero which was fine. I went to 600 and shot 2 more times, checking each shot. After the 3rd shot, I could not find a bullet hole in the group. ( I taped the previous holes shut) Then I noticed 3 irregular shaped holes on the paper about 3 feet apart. On closer inspection, it appears that the bullet come apart. It was the bullet that made the 3 irregular holes. I had no more time to keep shooting so I don't know yet what will happen with the rest. By the way, there was nothing between me and the target but air. I double checked.

What is up with this?
anyone else see this happen?

Daryl

If a bullet was going to break up (due to excessive spin and velocity), it would do so far before the pieces could travel 600 yards.

I would suggest that the bullet hit the ground in front of the target and dusted it with debris.

I agree, bullet break up is right out of the barrel or none at all...you hit the ground and got a bounce, easy to do at 600 yards.

A rifle sighted in dead on at 100 yards will drop 29' at 1000 yards. You may have over estimated how flat your rifle shoots at 600 yards. The bullet probably hit in front of your target and came apart then hit the 5'x 8' paper. If your rifle is sighted to print 3" high at 100 yards it will strike low at 600 yards. Place the 5'x 8' paper with the 8' vertical and hold so your cross hairs are at the very top edge of that paper. You will be surprised where the bullets strike.