Rifle Scopes scope slipping forward?

[bloodsport06]

hey guys. i have a vortex pst 6-24x50 rifle scope and a set of griffin armament etac rings. i tightened the rings down to 18"lbs as the instructions stated. these are a zero gap ring. i went to sight in my rifle and was having a hell of a time. finally got it where i wanted it. well a few days later went to confirm zero before deer season started. first couple shots were ok then it went bad. i went through about 4 boxes of shells thinking it was me. finally realized my eye relief had changed. looked at the scope and realized it had moved all the way forward. i went home and rechecked the torque settings on the screws to see if they had loosened. they did not. i called griffin and vortex up, vortex said try 20" lbs and that didnt work. after a box of shells same thing. griffin armament finally called me back and suggested i get some cloth duct tape and put it around my scope where it sits in the rings. (I was wrong, griffin did not recommend using tape, that was someone else, i apologize) does anyone else think thats bs? i dont want have to do that. i paid 130 for the rings. i emailed brownells to see if i can send them back to get some tps rings. is this normal to have to do? ive never ran into this before. thinking its because its a zero gap ring possibly and maybe somethings out of spec. what do you think?

 

[EddieP]

If they are zero gap then I can't see more torque helping. I'd assume someone's tolerance is out, so that is either the rings or the scope tube. I'd send them back and get some other rings.

 

[Graham]

1) Rings are supposed to have a gap. That's how they work properly.

2) Duct tape? Seriously?

Send them back and buy quality rings, which are available for the same price.

 

[Nate O.]

take a O.D. measurement of the scope tube and an I.D. measurement of the rings torqued down. Then you will know what you're up against and have some info for each respective customer service.

 

[bloodsport06]

actually brownells customer service said to use cloth duct tape also when i called them. then i sent the email asking if i can return them for another set of rings. ill get measurements when i get a chance. either way i think a new set of rings without the zero gap feature will solve the problem even if the scope tube would happen to be slightly off. sucks i dont even trust the rifle to take a deer right now. dont wanna wound one

 

[GONIF]

I would send them back and get rings that are in spec . In the event you are keeping the rings that are loose ,you can use a bit of black RTV and the scope won't move again . Old trick ,but works great .

 

[11B-B4]

I talked to the OP and offered to check out the scope and rings. He said hes probably going to handle it with brownells. FWIW, we have sold about 400 sets of these rings and this is the first issue we have heard about. We also noticed in our development of the product that the Tube OD was all over the map depending on manufacturer and model so I think it presents a difficult problem for ring manufacturers. This is why i think most ring manufacturers do not do gapless designs. Having a significant amount of gap allows a ring to crush some geometry on the tube even if the tube is out of spec.

Again so far so good IMO 1/400 users have had negative feedback. I think at this rate gapless is still an up sell to me at least. I never liked ugly rings. If anyone else has problems please email me at [email protected] we will take care of it. All of our products carry a manufacturers lifetime warranty against defects in manufacturing.

-Evan

 

[11B-B4]

1) Rings are supposed to have a gap. That's how they work properly.

2) Duct tape? Seriously?

Send them back and buy quality rings, which are available for the same price.

For the record our rings do have a slight gap... on proper tube sizes that we used in our R&D case study they should have about ~5 thou per side. It looks relatively seemless but there is a slight gap.

 

[MrSwede]

I'd recommend you not use shotgun shells in that rifle.

 

[GerryVa]

A lot of less expensive scope rings have about 20% surface contact with the scope when aligned and you start to lap them. That's why a lot of manufacturers are now putting tape in them from the factory. I should have said some of the least expensive manufacturers that I've seen lately, not a lot, sorry

 

[bloodsport06]

appreciate your pm evan, always like a company that is looking out for their product. the quality of the rings are awesome. ill post a pic of the rings on my scope. maybe that will help you see what im talking about. i dont have a gap in my case. if theres any chance you think the my rings could be out of spec i may just send them to you. i cant just go buy another scope so id have to find a ring that would work for my rifle scope. thanks for the good customer service so far tho

 

[bloodsport06]

pics

 

[11B-B4]

It's possible but not probable. Alot of ring manufacturers saw cut their rings in half and then surface grind them or mill them into flat again. We have a fixture so that the rings are zero'd out and then EDM'd in half at the zero axis. Send them in and I will check them out. It would be great to have them with the scope though.

If you'd like i can shoot you out another set in the mail that you could try out in case you need your rig for hunting. I can drop them in the mail tomorrow. PM me your address.

-Evan

 

[HPLLC]

I called you back and left a voicemail. E-mail is a better form of contact for a rapid response. I didn't mention duct tape. I mentioned mounting the scope with the W/E housing against one of the rings so that recoil could transfer mechanically rather than relying solely on clamping force of smooth surfaces. In some cases, the modern optics are getting very heavy, and when you couple that with a heavy recoiling rifle- that can cause scopes to slip. I mentioned increasing torque is fine also- but caveated that that may at a point damage a scope. The ring screws will hold to 2-3 times the recommended torque load, but the scope tube might not take that. There are several manufacturers of optics who use tube sizes smaller than actual size. That's bad form on them, because 30mm is a dimension- it's not a suggestion. Sorry for the trouble, and for the late response, we stay busy at work, and are often talking to machinists on the floor and it isn't always possible to field every call on the spot.

 

[PittsDriver]

Listen to Graham on this one.

 

[phreakmode]

A lot of less expensive scope rings have about 20% surface contact with the scope when aligned and you start to lap them. That's why a lot of manufacturers are now putting tape in them from the factory.

You lost me on this one. Seekins rings don't have tape, Badger rings don't have tape, Nightforce rings don't have tape, Talley rings don't have tape, APA rings don't have tape, Spuhr rings don't have tape, Leupold rings don't have tape. What is this "a lot of manufacturers" you are referring to?

 

[GerryVa]

I edited my statement , you are correct , it's just the cheapest ones I've seen lately Phreak , not" a lot"

 

[jdgray]

Not that it matters, but I'd move the front ring forward about 4-5 slots on your rail. Unless that's where your scope landed after firing....

 

[bloodsport06]

I called you back and left a voicemail. E-mail is a better form of contact for a rapid response. I didn't mention duct tape. I mentioned mounting the scope with the W/E housing against one of the rings so that recoil could transfer mechanically rather than relying solely on clamping force of smooth surfaces. In some cases, the modern optics are getting very heavy, and when you couple that with a heavy recoiling rifle- that can cause scopes to slip. I mentioned increasing torque is fine also- but caveated that that may at a point damage a scope. The ring screws will hold to 2-3 times the recommended torque load, but the scope tube might not take that. There are several manufacturers of optics who use tube sizes smaller than actual size. That's bad form on them, because 30mm is a dimension- it's not a suggestion. Sorry for the trouble, and for the late response, we stay busy at work, and are often talking to machinists on the floor and it isn't always possible to field every call on the spot.

If you are correct I truely apologize. I feel like a total dbag for mixing that up. I was talking to you, brownells and vortex. Must have been brownells and vortex who suggested the tape. The guy I talked to said he hates to recommend it but I could use cloth duct tape. I deleted the voicemail so I cant double check. I believe you tho. I was frustrated and searching for a quick answer. This thread was in no way to dis griffin rings. They look awesome and feel heavy duty. When I received them I was stoked. I showed a couple buddies and they were jealous lol. They have walmart rings, but there doing the job. Ill pm my address so I can try a diff set. If they hold my scope ill send you my ones from brownells back, if they dont ill send you the set you just sent me and ill send brownells the other set for a refund. Once again sorry for the confusion. Thats on me. I apologize

 

[bloodsport06]

Not that it matters, but I'd move the front ring forward about 4-5 slots on your rail. Unless that's where your scope landed after firing....

Yeah thats where the scope is sitting after firing a box or 2 of shells. I had it further back. With this heavy of a rifle and being a 308 theres not much recoil.

 

[bloodsport06]

Griffin armament so kindly sent me a new set of rings to try. I am attaching a couple pics of how they are sitting without the screws in place, this is just the upper half resting on the scope body without any pressure. Had the same size gap on the other side as well. I think im going to have the same problem. Going to find a way to measure my scope tube diameter. Thinking thats the problem when it comes to these rings with my vortex pst. I havent shot the gun yet since I mounted the scope with these new rings, hopefully this weekend will be able to burn through a couple boxes to see if the scope will stay put. Just wanted to do an update. Kudos to griffins customer service!

 

[bloodsport06]

This is the most consistent measurement im getting without putting alot of pressure on the dial wheel.
1.179" equals 29.9466mm
Is that enough out of spec to cause the issue? It reads more then that usually but if I position the calipers just right I get this reading. Wish I had a digitial calipers, I will try and hunt down a pair.