The Phenomenon Of Guns or Scopes Shooting Loose

[SloppyJ]

I missed a chip shot on a deer sitting on a field edge with my son on one Thanksgiving afternoon. The buck hopped the fence and landed 15' from us. It stared at us forever as my son was in my lap and trying not to giggle. He was 4 at the time. He ran off about 50yds and stopped. I hit him, good blood but quickly dried up. Never found that deer and I looked for HOURS. Anyway, I get home and the action screws on my model 70 were extremely loose.

I have a Winchester Model 100 243, super cool rifle. I took it out one year for nostalgia and when I racked a bullet in it (semi-auto), the bolt got stuck forward. If the rear action screw loosens at all, the bolt falls forward over the trigger and it's locked shut. This is actually a common problem in that rifle. Had to take it to a smith and get the stock broke to get it fixed. They did a great job and you can't even tell.

I've had scope mount screws back off as well.

So my answer is yes to all of the "questions".

 

[RockAndSage]

Yep. Most of what I learned about bedding scope bases, lapping scope rings, and using some sort of thread locker on fasteners was all learned the hard way as a kid. Mostly trying to get a scope base to stay put under a 30-06 I was shooting a lot, and later on after damaging a scope from relatively little over-torque on good rings that weren't lapped. Not having much money growing up, it was JB Weld under the base and clear nail polish on the ring fasteners, and later on it was more specialized bedding compounds from places like Brownells, and loctite.

Something that does not seem to get mentioned much is the role of recoil and inertia. The lighter the rifle, the heavier the scope, and the more powerful the cartridge, the more you are likely to see scope slip and bases coming lose. The rifle is essentially trying to fly backward out underneath the scope - the lighter the rifle and the heavier the scope, the easier that is as recoil energy increases. So, an ultralight mountain rifle chambered in .300 PRC, running a heavy scope, is far more likely to loosen things up at much lower round counts than an 8lb .223 with a lightweight scope.

 

[ResearchinStuff]

I've had scopes slip and base screws come loose. I've also had every single screw on my bow work loose. Degreasing, using loctite and a torque wrench has eliminated those issues.

 

[TaperPin]

I’ve had very good luck not using thread locker and simply regularly checking torque, but I should add that I’m using torque that’s on the high end and that helps prevent things from loosening up. Rod bolts on an engine don’t have loctite or lock nuts and the torque keeps the nuts from working loose - how often does anyone drop the oil pan to check the rod bolts?

 

[svivian]

This thread would be better with a Poll at the top to vote to better track. Just my .02

 

[MuleyFever]

For those that Loctite the action screws, how are you heating up the screw to remove it? I would think you would damage the stock.

I had my Talley scope bases come loose on my Kimber. The base screw holes go through the top of the receiver. I think that while cleaning the patch would rub the top of the boly area a bit and oil migrated into the threads because when I removed them there was oil under the base.

 

[Dave0317]

I’ve never had it happen to one of my rifles. I’ve seen it on plenty of others.

I think I’ve seen it on 22s more than anything for a few reasons.

1. People shoot high volumes of .22 compared to center fire.

2. Lots of people buy cheaper scopes, rings, and bases for their .22s than for their center fire rifles.

3. Lots of guys have never even seen a torque wrench, let alone set the screws to the manufacturer’s recommendation.

With all that said, I’ve installed plenty of mine that I don’t degrease anything. Sometimes I even add a drop of oil, due to being in a very humid part of the country.
I Just torque properly and leave it be. Never had one shoot loose.

 

[Macintosh]

I’ve had very good luck not using thread locker and simply regularly checking torque, but I should add that I’m using torque that’s on the high end and that helps prevent things from loosening up. Rod bolts on an engine don’t have loctite or lock nuts and the torque keeps the nuts from working loose - how often does anyone drop the oil pan to check the rod bolts?

Dont larger bolts like that allow for enough torque to somewhat stretch the bolt so it stays under tension? My impression was that smaller screws like youd find even on an overbuilt scope ring dont allow enough torque to do this, even if you push the torque a bit. If true (??) that would be a somewhat apples-to-oranges comparison.

 

[Billy Goat]

I can't remember a scope bolt loosening, but I have had and seen several bases loosen to the action.

 

[Macintosh]

This thread would be better with a Poll at the top to vote to better track. Just my .02

So far (not counting billy goat just above^^)
No, never had it happen: 6 (28.6%)
Yes, had it happen or seen it: 13 (61.9%)
No, but I use loctite: 2 (9.5%)

Seems pretty clear it’s a significant thing, the question is why. Theres an awful lot of variables in play. My guess is until someone does a controlled test using same equipment, same torque, same conditions, etc and controls a group for each of various variables to isolate what is causing them to loosen, we’ll never know.

 

[Antares]

The enthusiasm for discussing topics ad nauseam around here is, at times, truly remarkable.

 

[Boltgun]

I cut my teeth racing off road motorcycles. EVERYTHING with threads gets loctite. (MuleyFever, if you use blue loctite it does not require heat to remove. Just extra torque to remove once it sets up.)

Stuff still came loose until I paired it with a good torque wrench.

 

[AZ_Hunter]

Blue locktite with the little amount of torque on rings (20ish in/lbs) shouldn’t require any heat to break loose.

If there is ever a need to heat, a soldering iron placed right on the bolt works well.

 

[Luked]

I have had cheaper rings come loose before. But never yet a higher end ring set or base.
I do now though do what Form does with nail polish just for good measure.
Makes a bit of a talking point also when people ask about it.

 

[V35B]

In have never had them come loose. After reading the thread on loctite, im going to start drilling the heads and safety wiring mine.

 

[Mike D Texas]

I’ve personally never experienced it. My most used rifle is a R700 5R Milspec in 308 that has almost 6k rounds through it. It has one of the old Leupold Mark 4 scopes on it in Seekins rings. I’ve never had to re-zero it or tighten anything back down.


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[TaperPin]

Dont larger bolts like that allow for enough torque to somewhat stretch the bolt so it stays under tension? My impression was that smaller screws like youd find even on an overbuilt scope ring dont allow enough torque to do this, even if you push the torque a bit. If true (??) that would be a somewhat apples-to-oranges comparison.

It’s not a perfect example - industrial sewing machines and their screws are probably a much closer comparison. Still, if screws aren’t torqued fairly tight they loosen up, if over torqued a little too much they snap off, and between the two has worked well for my mentor since the early 1970’s and has worked for me since the early 1990’s. I wouldn’t care if a trainer/plinker loosened up with a high number of shots, not that they have. A hunting rifle gets checked before the season and only fires a handful of shots to check zero and during the season.

There are different ways to skin this cat - someone just has to find a system that they are comfortable with and is reliable. I’ve never come home with a loose screw in 3 decades so that’s good enough for me. I can see the attraction to loctite and and a painted on indicator that cracks if a screw moves. I went through a stage of trying it, but quickly became annoyed cleaning screw threads every time something new was tried, or swapped around.

 

[Macintosh]

Thats fair. And agree with more than one way. Probably a little equipment-dependent as well. The last one I had a problem on was a ring base that came loose on my 22 during a match. I checked zero in the am, shot a bunch of the match, and there was a paper stage that I absolutely bombed, that I should have done way better. So I checked zero afterward, and was all over the place. Pulled the whole rig apart when I got home and discovered that the base had come loose under the front ring—I dont recall what rings they were but I dont believe you could access those screws with the scope on, so Im not sure how I could have checked it. Regardless, it loosened mid-match. Not a big deal except super frustrating, thats when I started loctiting stuff. For me the no-threadlocker didnt work, and even though there may be a way to make it work without using it, the threadlocker has been working and doesnt have a down-side to me, so I stick with it. I dont switch my stuff around enough for gummed threads to be an issue.

 

[Strider]

Not on a personal rifle but since March of this year I have seen two separate rifles come loose at the bases and another rifle have very loose action screws.

 

[DiabeticKripple]

For those that Loctite the action screws, how are you heating up the screw to remove it? I would think you would damage the stock.

I had my Talley scope bases come loose on my Kimber. The base screw holes go through the top of the receiver. I think that while cleaning the patch would rub the top of the boly area a bit and oil migrated into the threads because when I removed them there was oil under the base.

no need to heat up anything using blue loctite