I noticed that myself and at least one other shooter had an issue with scopes coming loose during the KD shoot in Manchester, TN. It was mid 80s for most of the day and we left our rifles below the 100yd berm between rounds. While we were in the target pits, the rifles were in the sun. Although they were under a towel, the heat was all around!
Did the heat make the scope rings grow and let the scope slide? My rings had the adhesive band-aid tape thing installed and I noticed that they had slid out from under the scope ring as well. I want to have equipment that can withstand the heat. Would steel rings hold on better?
Quote from: Hardbean on May 30, 2014, 12:48:09 PM
I noticed that myself and at least one other shooter had an issue with scopes coming loose during the KD shoot in Manchester, TN. It was mid 80s for most of the day-, the heat was all around!
Is this considered hot in Tennessee? ???
I very much doubt that scopes became loose because of thermal expansion of the aluminum rings. Rifles get left in hot cars and used in warm climates all the time with no ill effects.
While scopes do often come loose at shoots, generally it is because they have not been properly tightened.
If vibration has definitely been ruled out, my guess is that the tape stuff is the culprit - many polymer-based materials flow and thin with heat.
We do a lot of shooting in Arizona in direct sun in triple-digit temperatures (when it gets down to only 80 here, we put on a sweater ;D), and I've seen an instance of where heat cracked an optic in a scope, but never one where heat alone loosened rings that were directly in contact with the scope body - that's usually a vibration issue. That's not to say that it's not possible - the differential of CTE (coefficient of thermal expansion) between aluminum and steel is about 6 microinches per inch per degree F. Although most scope bodies are aluminum, if you had a steel 1" dia. scope body in aluminum rings, the expansion difference over a 100 degree F increase in temperature would be about 0.0006" - that might loosen a ring if it wasn't very tight in the first place. But if you put something plastic in that interface, I would guess that the heat softens it and it will flow out of that interface until the pressure induced by the rings is relieved - i.e. they are no longer tight.
First, welcome to our forum.
Scopes should not need tape of any sort. The rings should hold the scope without any assistance.
Remove the scope, remove the tape (use rubbing alcohol to get rid of all the sticky stuff) and remount the scope. Tighten down the screws then remove them 1 at a time add a drop of BLUE LOCKTITE and re-tighten the screws.
2cl
Buy good quality scope rings and use powdered rosin for extra grip between the rings and scope body.
http://www.brownells.com/gunsmith-tools-supplies/general-gunsmith-tools/vises-accessories/vise-accessories/rosin-prod1123.aspx
I use a very small dab of silicon on the rings. Goop I think is the little tube I have. This was recommended by Boston T Party if I'm not mistaken.
JoeZ
Dont tape the rings, and its typically a bad idea to use loctite or silicon on rings. Just to be honest buy good rings and this wont happen.
Removing that tape MIGHT fix your problem but good rings definitely will.
1. Tape was a bad idea.
2. Those rings were suitable for occasional shooting, but not high round counts.
3. Loctite anything and everything you don't want coming loose when people are shooting at you.
4. Silicone on the scope body may be overkill, but it works
5. Buy better quality rings.
https://www.badgerordnance.com/product-category/scope-rings/30mm/
http://www.leupold.com/tactical/mounting-systems/mark-4-mounting-systems/mark-4-30mm-medium-aluminum/
http://www.burrisoptics.com/xtrrings.html
http://www.midwayusa.com/product/1477135627/weaver-6-hole-weaver-style-rings-matte?cm_vc=ProductFinding
Thanks for all the help and tips so far!!!
Since this was my first KD, my kind neighbor let me borrow his Savage Model 10 rifle. The scope was a Bushnell 3-9x40. The rings were unmarked so I guess they came with the gun or scope. I didn't even know there was tape in the rings until I was shooting the third AQT.
I like the sound of the powdered rosin but I wonder if exposure to heat (outdoor temps plus lots of shooting) would cause it to loosen up just as the tape did. I've also found where you can lap the rings to improve concentricity and hopefully increase the contact area of the rings on the scope. http://www.midwayusa.com/product/227261/wheeler-engineering-scope-ring-alignment-and-lapping-kit-1
Just before we shot the KD, I checked the scope ring's screws and I found two that were loose. I snugged them down and went about my business. I thought all was well until I noticed the movement. Obviously, I didn't tighten everything down properly. I'm more or less looking for manufacturer's information or articles about proper scope mounting (methods, torque values, etc) not just "buy better stuff" which seems to be what everyone on the internet says. If my (neighbor's) rings were adequate but just not properly installed, I'd like to know how to fix them. So far, I've only found a few online tutorials that recommend torque values from 15 to 25 INCH-pounds for the screws. The internet is full of 10 times more MIS-information than solid information, but I trust you guys quite a bit more than other resources! ;D
The next KD event for me will probably be the Manchester shoot this coming Labor Day weekend. I've got until then to build a rifle+scope setup. I'm really interested in the idea of being a "field shooter" along with having gear that is rugged, sturdy, and as light as possible within monetary reason.
Aligning the scope rings by lapping is just part of mounting a scope with two separate rings and should have been done. One piece ring mounts such as spuhr, or aadland don't need to be lapped. The powdered rosin will not come lose in the rings with heat or lots of shooting (thousands of rounds). It's a fine powder that is dusted on the rings just before tightening for the last time. Rosin is also great for unscrewing stubborn barrels ( strap wrench).
Begin with quality rings and you will probably need no lapping. Leupold recommends 22 in-lbs for 6-48 base screws on their Mark 4s. Badger rings are not that far different. Yes, I torque my rings!! Doesn't make sense to mount a nice scope on your rifle with so-so rings. You get what you pay for. Forget tape, rosin, or any kind of witches brew.
aj