Rifle Scopes ARC ring torque with ZCO?

This has been addressed before with ARC rings but not necessarily ZCO optics.

Yes, it will be fine. I have ARC rings on Vortex optics with no issue. Do I have a ZCO? No.

The spec provided by optic manufacturers are generally with rings that have four or two screws; where less torque is needed for small, numerous screws to impart clamping force. ARC's rings have one screw and it's a larger screw; thus the high torque value.

Painless300 said:

Need some help on what to torque my ZCO in ARC rings.
ARC recommends 50-55 in/lbs of torque and ZCO recommends not to exceed 25in/lbs.
Is 50-55 safe to use on the ZCO tube?
Just don’t want to take a chance in damaging a brand new scope.

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Yes it is. With ARC rings that’s the only exception to going that high in ring torque because of the 1 screw design. When I was using their mounts I always used 55in/lbs

ARC rings works in a different way than standard rings therefore requiring more torque to its single bolt.
I’d totally use the ARC recommendation.

Adding...

I know that ZCO is active on this forum, so it would be great to see an optic manufacturer address this directly as ARC rings are very popular and there is always shock value when first seeing the recommended torque value.

Painless300 said:

Need some help on what to torque my ZCO in ARC rings.
ARC recommends 50-55 in/lbs of torque and ZCO recommends not to exceed 25in/lbs.
Is 50-55 safe to use on the ZCO tube?
Just don’t want to take a chance in damaging a brand new scope.

Click to expand...

The 25 inch pounds spec is for a different design. Still the 50-55 in/lbs on the ARC is more than sufficient with heavy recoiling calibers, so if you have a light or medium recoiling caliber you could try a little less on your ARC. I have a MRAD that I shoot mostly with .260 or .308 I torqued the ARC to a very gentle 45 in/lb and it has not slipped yet. If you have a lightweight unbraked magnum for hunting (or you want to be sure it will not move) you are going to want to go right to the spec.

Painless300 said:

Need some help on what to torque my ZCO in ARC rings.
ARC recommends 50-55 in/lbs of torque and ZCO recommends not to exceed 25in/lbs.
Is 50-55 safe to use on the ZCO tube?
Just don’t want to take a chance in damaging a brand new scope.

Click to expand...

I'm not sure where you see that we don't recommend more than 25 inch pounds. The literature and Operator's Manual clearly say to use the ring manufacturer torque specs. I know, I wrote the manual.

ZCO scopes will handle the ARC torque just fine as they specify. No worries at all.

Odd, I believe that caution was removed, but obviously I'm wrong. Still no worries, use the ARC recommendation for tightening to the scope tube.

Don't undertorque, had a set slipping down at FTW Ranch when it was set at 35 in lbs.....

Retorqued at 55, never slipped after that

5 years late to this but muchas gracias.

Maggot said:

5 years late to this but muchas gracias.

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We have sold thousands of ARC rings and mounts with success, and I've used them personally on my older setup last year and the shop gun with our ZCO from the early years.... - Richard