Mounting NF SHV in Seekins Rings - Scope Tube/Ring Issue

[BrentH]

I’ve been using Seekins rings for the past 5-6 years with no issues. Today I went to mount a brand new SHV F1 in a set of 30mm Medium rings. I set the scope into the bottom half of the rings (already mounted on the rail), and then set the ring caps on top. When I went to slide the caps to get them lined up, the one on the objective end of the scope wouldn’t move.

Pulled the scope off and placed just the ring caps on it to see if they would rotate around the scope body. The objective end would not rotate (the ring was grabbing the scope tube), but the eyepiece end would rotate with minimal resistance. Swapped the ring caps (one end to another), and then they would both rotate with slight resistance.

Does it seem like something is “out of round”? Should I try a different set of rings? Maybe something with the scope tube? I just don’t want to torque them down if the ring is biting into the tube too much.

 

[Samson7x]

Assuming it’s flush with no gap between scope body and ring cap, seems like it’s just machining tolerance stacking and a very precise fit. I’d roll with them.

 

[Mag_7s]

Do you have a lapping bar?

 

[SDHNTR]

I’ve had the same happen with ARC rings. Send em back.

 

[Diced]

You could lap them but rings of that quality shouldn't need it. I'd send them back.

 

[BrentH]

You could lap them but rings of that quality shouldn't need it. I'd send them back.

Kind of my thought as well.

 

[BrentH]

Wanted to follow up on this thread.

I got another set of Seekins rings from a buddy, and also ordered a set of ARC M-Brace rings. Both new sets of rings, I experienced the same issue.

Not sure why I didn’t think of it before, but decided to pull out my micrometer, and take some measurements of the scope tube.

Measured side to side, the tube between eyepiece and turret measured a consistent 30.02mm. The section of tube between turret and objective measured from 30.06mm to 30.08mm as I moved forwards and backwards on the tube.

I called Nightforce, and he was very helpful. Said I could send it in for them to inspect, or since I’ve only owned it a week, I could see if Cabelas would exchange it, and then Cabelas could deal with sending it back to NF. I am going to try the Cabelas route first, because I think it would get me a scope in hand slightly quicker, but if they aren’t willing to help me, I’ll be sending it to NF.

After talking with NF, I then measured the scope tube top to bottom and at a diagonal measurement (to see if the tube was out of round), and on that objective end, I hit measurements as high as 30.12mm.

 

[Samson7x]

Wanted to follow up on this thread.

I got another set of Seekins rings from a buddy, and also ordered a set of ARC M-Brace rings. Both new sets of rings, I experienced the same issue.

Not sure why I didn’t think of it before, but decided to pull out my micrometer, and take some measurements of the scope tube.

Measured side to side, the tube between eyepiece and turret measured a consistent 30.02mm. The section of tube between turret and objective measured from 30.06mm to 30.08mm as I moved forwards and backwards on the tube.

I called Nightforce, and he was very helpful. Said I could send it in for them to inspect, or since I’ve only owned it a week, I could see if Cabelas would exchange it, and then Cabelas could deal with sending it back to NF. I am going to try the Cabelas route first, because I think it would get me a scope in hand slightly quicker, but if they aren’t willing to help me, I’ll be sending it to NF.

After talking with NF, I then measured the scope tube top to bottom and at a diagonal measurement (to see if the tube was out of round), and on that objective end, I hit measurements as high as 30.12mm.

Oh wow, glad they are taking care of it. I realize NF isn't infallible, but I would have suspected rings over scope tube any day.

 

[BrentH]

Was able to get the scope exchanged at Cabelas today.

New scope drops right in to both sets of the Seekins rings like I would have expected, with no binding.

Can’t say the same for the Arc rings, unfortunately. Upon closer look at one of the rings, there is a slight burr protruding out off the ring near the hinge that is causing the excess pressure on the scope tube. I purchased these rings from Short Action Precision, so I have an email into them to see about returning them.

 

[Diced]

Was able to get the scope exchanged at Cabelas today.

New scope drops right in to both sets of the Seekins rings like I would have expected, with no binding.

Can’t say the same for the Arc rings, unfortunately. Upon closer look at one of the rings, there is a slight burr protruding out off the ring near the hinge that is causing the excess pressure on the scope tube. I purchased these rings from Short Action Precision, so I have an email into them to see about returning them.

That's good cabelas exchanged the scope. Seems like you were the recipient of a couple bad cases of QC haha.

 

[2-Stix]

I installed some UM rings on a Tikka with a NXS last week. I use feeler gauges to get my rings as even as possible when I torque them down. I did notice that the back tube was tighter than the front tube.