Whenever I get a group like this its usually powder charge related.  You might be just slightly missing the perfect recipe for the accuracy node with this factory ammo,  .2grs plus or minus may tighten the group right up…No change to setting depth.  That's the problem with factory, what might be perfect in 1 rifle may not work in another.

BUT…I also see almost identical results when I'm shooting a perfect hand load that usually produces 1 hole or all touching groups…but opens up over a “broad” temperature range.  Meaning on a warmer to hot day during range test / load development its a 1/4moa load,  and on a cool fall or winter day it opens up to 1/2-3/4moa,… All corrected by upping or decreasing powder charge slightly to accommodate the temp change, even when using temp stable powders.  If you shoot the same ammo you tested above during a big temperature swing you may have better groups, but can't say if it will be better in hotter or colder weather.

It's not a bad group with factory ammo! Looks to be just over 1/2moa (minus the top flyer)…if that load holds during various temp changes then you have a good go to for sure.

I'm no expert so fwiw-
Vertical stringing is often due to velocity variations between rounds, while horizontal spread can often be helped with bedding and/or pillar job and a lighter trigger.  Also if you are shooting off a bipod on a hard surface the rfle's harmonics can be inconsistent.  Use a piece of carpet on hard benches or shoot off of  sandbags for consistancy.

If you know of someone who's a good shot have them try it.

If you want to consider possible things you may be doing:

–  how's your natural point of aim?  If you get into position with the crosshair on the target, and then close your eyes and go through two breathing cycles and open your eyes, is the crosshair in the same place?

–  is the first pad of your finger flat on the face of the trigger and pulling straight back? 

–  is the parallax adjustment on the scope correct?

–  are you pushing against the stock with your cheek/face?

ShtrRdy,  makes all good points.  Parallax has challenged me on occasion at the range.

Here's an example of horizontal stringing regarding powder charge…with 44.8grs of Varget my groups would
spread out to 1-1.5″ horizontally @ 100yrds, but vertical would stay @ 1/4-1/2″. The powder charge produced this pattern consistently on numerous groups.  I upped the charge to 45.1grs and it tightened up…shot this 10rd group all within the same 3/4″ ragged hole with my CTR.  No change to COAL, .3grs made the difference. 

My point…no matter what you do as a shooter, even if you have perfect form,…your rifle may only shoot the factory ammo you tested so good. You might be doing nothing wrong. The group you shot may be the best it gets.  Thats why I turned to hand loading…

Check the results of this OCW test showing groups…
Accuracy node @ 44.5grs shows some horizontal stringing, 44.7 tightens up, and better yet at 44.8…
Accuracy node @ 45.4grs shows same horizontal stringing, 45.6 tightens up, and 45.7 is beautiful for 100yrd paper punching.

The fact that you are putting “multiple” bullets in the same hole at 100yrds and able to get repeating groups leads me to think its more ammo related and nothing to do with form. Putting 3 shots in 1 hole and 2 shots in another less than 1/2″ away is pretty dam good… If your form or trigger pull was bad it would be more random and more spread out patterns, not multiple bullets going through the same hole.

You are right at the edge of an accuracy node that a slight change to powder charge or even seating depth would turn your repeatable pattern into small 1 hole clovers.  Too bad you don't have a press to pull the bullets and play with the setting depth on the factory ammo, that has worked for me in the past.

Try some 155gr Nosler or hornady match through the gun and report back.