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Pleistarchus
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BREAK BREAK... Been following this thread for some time now. Nothing more is going to be constructive so if there was a good time to highjack now is it. If you for some reason feel inclined to move your SPUHR mount. PM ME first please. Looking for 34mm 20 MOA model 4616
And Randy thanks for fielding my call the other day. I have an order coming soon for you!
And Randy thanks for fielding my call the other day. I have an order coming soon for you!
I'm coming in late but this thread was just brought to my attention. In my opinion, rosin and Loctite is a good idea regardless of how much you spent on your rings and mounts, especially if they are made from anodized aluminum. The reason for this is that there are competing effects at work. In order to keep the scope from slipping through the rings, a high clamping force (high torque on screws) is desired. However, applying large clamping forces to the relatively thin wall of a $3500 aluminum scope tube seems like a really bad idea, an it is. I recently had a customer call me who literally deformed a Steiner tube to the extent that the internal mechanism were rendered immobile. Thankfully, he didn't do this with my rings.
Anodized aluminum surfaces are slippery. If scope mounting is your objective, this can and often does cause problems. However, light-weight, relatively high strength, and corrosion resistance are pros that out-weight the con of low friction which is why manufactures of scopes and rings (me included) choose to use aluminum with an anodized finish. I tell my customers that ideally, they should apply just enough torque to the screws to hold the scope in place against recoil. If they can use rosin or Loctite to reduce the torque necessary to secure the scope, then by all means, they should do it.
When a scope tube is clamped in a set of rings, the tube is elastically deformed in a non-uniform way which causes the scope to bend. I am not aware of any rings or mounts that do not do this to the scope, including my own. Minimizing this effect seems prudent to me but, I've discussed this with scope manufactures and they didn't seem to bothered by it. Nevertheless, when confronted by issues such as this, I ask, "What good can come from greatly exceeding the clamping forces necessary secure the scope against recoil?" I'm still waiting for an answer.
I limit the force that can be applied to the scope by choosing a screw that will fail before damage can be done to the scope. The screw acts as a fuse and typically breaks around 70 in-pounds but that varies from screw to screw. Under normal conditions, 50 in-lbs seems to adequately secure the scope against recoil. 50 in-lbs may seem high when other manufacturers recommend 15 to 20, but that is because my rings use a single 5mm screw to clamp the scope. 50 in-lbs applied to a single 5mm screw will impart a tensile force close to that which two smaller screws will apply when torqued to 15-20 in-lbs. If you experience the scope slipping through the rings, you can safely apply more toque but introducing a sticky substance is the smarter thing to do.
I hope this helps. Thanks guys.
Anodized aluminum surfaces are slippery. If scope mounting is your objective, this can and often does cause problems. However, light-weight, relatively high strength, and corrosion resistance are pros that out-weight the con of low friction which is why manufactures of scopes and rings (me included) choose to use aluminum with an anodized finish. I tell my customers that ideally, they should apply just enough torque to the screws to hold the scope in place against recoil. If they can use rosin or Loctite to reduce the torque necessary to secure the scope, then by all means, they should do it.
When a scope tube is clamped in a set of rings, the tube is elastically deformed in a non-uniform way which causes the scope to bend. I am not aware of any rings or mounts that do not do this to the scope, including my own. Minimizing this effect seems prudent to me but, I've discussed this with scope manufactures and they didn't seem to bothered by it. Nevertheless, when confronted by issues such as this, I ask, "What good can come from greatly exceeding the clamping forces necessary secure the scope against recoil?" I'm still waiting for an answer.
I limit the force that can be applied to the scope by choosing a screw that will fail before damage can be done to the scope. The screw acts as a fuse and typically breaks around 70 in-pounds but that varies from screw to screw. Under normal conditions, 50 in-lbs seems to adequately secure the scope against recoil. 50 in-lbs may seem high when other manufacturers recommend 15 to 20, but that is because my rings use a single 5mm screw to clamp the scope. 50 in-lbs applied to a single 5mm screw will impart a tensile force close to that which two smaller screws will apply when torqued to 15-20 in-lbs. If you experience the scope slipping through the rings, you can safely apply more toque but introducing a sticky substance is the smarter thing to do.
I hope this helps. Thanks guys.
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Pleistarchus
Guest
Ted I am no engineer but I always asked myself why don't ring manufacturers put a thin layer of rubber on the inside of the rings. Being flexible and in some ways could be made to adhere to the surface of the scope with less pressure on the tube I would think that would help. Also thanks for chiming in. Literally having a third party scope ring engineer offer his 2 cents on a thread like this is what makes Sniper's Hide what it is. Thank you
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Pleistarchus
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Sorry Garrett, Mount has been sent in to Mile High for evaluation also it was a 4007 (no elevation). Thanks for asking.
The rubber is actually an interesting idea and something that I have not considered but my initial thought is that it would be tough to make it work over an extended period of time. The layer would have to be thin in order to hold up to the clamping loads and if moisture worked its way into the joint, I'd bet that it's grip would be compromised. I think that Rosin and Loctite are a better approach.
Late to the thread but here is my experience: Sako trg 42 in .338 lapua with spuhr 44.4moa dovetail mount, i have a S&B 5-25 pmii also running an aac titan on it. First 20 rounds where good, drove from CO Springs to Oregon, went shooting with my brother and started to get wandering hits at 300yds, it was at this point I noticed the scope had slipped. It slid enough to gouge a corner of the S&B, hurt my ego the most. Just recently I got a torque wrench and redid everything on the spuhr mount, replaced a couple ring screws and lined the rings with rosin.
I'm not a fan of loc-titing screws even with blu loctite only because if you have to send (scope/mount) back its a pita. Went to the range a couple days ago and had no slippage, though i did torque to about 30in-lbs. I love the mount but damm if i wasn't cussing a storm.
I just recently saw a scope at the range in a larue mount and the owner was bitching about his groups. I've had larue mounts and asked if i could look... this owner had installed most ofthe screws one way even though instructions say to alternate.
Just food for thought: everything can and will fail at some point----murphy.
I'm not a fan of loc-titing screws even with blu loctite only because if you have to send (scope/mount) back its a pita. Went to the range a couple days ago and had no slippage, though i did torque to about 30in-lbs. I love the mount but damm if i wasn't cussing a storm.
I just recently saw a scope at the range in a larue mount and the owner was bitching about his groups. I've had larue mounts and asked if i could look... this owner had installed most ofthe screws one way even though instructions say to alternate.
Just food for thought: everything can and will fail at some point----murphy.
I just got some rosin on midway. Does the rosin need to be liquified and if so, what do I use with it? If not liquified the just a sprinkle of powder on the rings?
Short answer is "no" but that may depend. I just mounted a third set of spuhr QDP cantiliver scope mount and rings. No where in the SPUHR instructions does it say to lap the rings. In fact they do have striations (slight groves) internal to the rings for gripping the scope solidly. Lapping would simply reduce the effectiveness of the gripping surface. Spuhr does say that some bench rest shooters prefer to use resin and loctite and it is fine to use those measures. Spuhr goes on to say that typical military and law enforement applications do NOT require rosin or loctite. I also shoot a 338 LM with spuhr QDP and have had no issues. So don't lap them is my suggestion.
9 years later to add a comment...
I'll be sure to pass on your recommendation to the retirees that began this thread.
I'll be sure to pass on your recommendation to the retirees that began this thread.
You are right; a liitle late response for the original poster but still a relevant question and Spuhr mounts are still being made and sold today. Lots of responses to a “yes” or “no” answer but I did not see the yes or no response. The answer was provided in Jan of 2022 by threadcutter308 when he said “no”. And that is the answer, “no” don’t lap Spuhr scope rings. Better late than never?
2022, NO. There hadn’t been a reply since 2014 until you just revived this dead thread. You joined the forum yesterday to bring us this wealth of knowledge?
Fuck the IQ level is getting low.
punishment shall be: death by a thousand memes, nipple twisters or stuperboot get to shave your balls.I have 10 spuhr mounts and none of them have rosin, the install says not needed due to the grooves in the rings. But rosin is popular with bench rest shooters. I haven't had any scope movement and my MRADS get the most used. Even the manufacturer on YouTube stated rosin is not needed. Installer preference is what I think it comes down 2
Not to worry, the penalties for not “doing a search first” are even worst…We call this the Hide Kobayashi Maru.
Out of curiosity… did you use rosin or loctite on the rings that cracked? I have mounted three and the fit is so good I can’t imagine loctite or rosin adding any value.I'm not sure about lapping but some of them definitely should have had this applied before installation.
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