Rifle Scopes Scope Issue: Consistent on .22, erratic on a .30-06, thoughts?

[11aaguilar]

I have another scope issue for the group. I have an Athlon Ares ETR 4.5-30x sitting in a Bobro Dual Lever Precision Optic mount. The optic is mounted to an RWS Gunsmithing blueprinted Rem 700 in 30-06. It's been consistent up until the last two range trips. I've been shooting Federal 180 Barnes TSX to get data and the rounds all over the place at 100 yards. I would make an adjustment after the first group, the first two rounds of the second group would reflect the adjustment and then after that rounds were back to hitting all over the target. By all over I mean up to 1.5 mils off at 100 yards. The best group I could manage was probably 4 inches. Nothing was consistent.

Thinking it's the scope, I took a Bushnell 3.5-21x DMR II in a Larue mount from my .22 and swapped them to see if the issue would follow. First 3 shots with the 30-06 and the DMR II were sub MOA, very consistent to how the rifle normally performs. The Ares ETR on the .22 shot just fine as well. I then swapped the scopes back and once again, the 30-06 is printing 4-5 inch groups at 100 yards.

At this point I've confirmed it's not the rifle, but am dumbfounded as to what's happening. I'm looking for suggestions as to what to do next, how to diagnose, etc. Could there be a fault or something in the Ares or Bobro mount that is recoil sensitive? Something that wouldn't present itself on a .22 but on a 30-06 firing 180gr bullets at 2800fps it would? Thanks in advance.

 

[_Windrider_]

It's probably the mount. Check the torque. 30-06 is not a forgiving recoil.

 

[Kbh]

I would also check the bobro mount. If everything is tight there i would mount the scope in a good set of rings like Seekins, nightforce, or badger and try that. Then you'll know if it's the mount or the scope itself.

 

[11aaguilar]

Ok. I should clarify I checked the action in the chassis, I checked the scope rail itself, I checked the mount attached to the rail, and checked the scope within the mount. This was not a legit torque check, so I’ll do that next, but just a wiggle check to see if anything moved, which they didn’t.

 

[hlee]

As stated above, though not as explicitly, mount the scope in a good unmount (Nightforce, etc) that uses cross bolts and not throw levers. Torque those bolts to the manufacturer's specifications. Bin the QD mount.

 

[11aaguilar]

Yeah. I have a pair of ARC rings not being used so I’ll try those as well. The Bobro is a $300 mount so I thought that inferred quality but it seems the general opinion here is to stick to conventional mounts.

 

[260284]

I had an ETR take a dump on a 20lb 22BR. They got me a new one right away, but it is sitting waiting on a 22.