First load I worked up for a buddy's 7mm Rem Mag. Honest to God 5 shot group @ 100. I'm calling it 3/8" which may be arguable but can't argue with less than 1/2".

Nosler 150gr. Ballistic Tips with 63.0gr. IMR-4831.

I assume that it is only the two holes you are measuring.
What are the other two holes in the picture?

Nice group. It's not bragging if you can do it more than once!

Exactly.One group can be a fluke but if it is repeatable,the rifle and load are a very impressive combination.

I quit using sheet metal backers years ago due to the fact of what can happen to your target, there is alot of bullet splash that can make big holes in the paper. I now either use fresh plywood or 1/2" felt board and dont shoot in the same place alot.

In this picture, the white center measures 3/8ths of an inch across and is a regulation 100 BR target and is made of heavy wieght paper, they work well. Resembles the test target the rifle came with(6.5x284)

There is only one other to the left and it is from a .44. What may look like one to the right is, like doublea said, torn paper from using a metal sign as backing. Not normal practice for me but it is what was on hand.

Dang nice shooting. I should go back to that load with my newer 7mm, went to 160 Accubonds and since they shoot 3/4" to 1" I've not wanted to stray much..

Nice shooting. Let us know how it works when you try it again....