Miata Mike
Member
I am going to mount a Leupold 2X scope on my S&W 629 Classic, and want to secure things against the .44 magnum recoil. I also want it to come off cleanly some day. Is Blue Loctite 242 a good thread locker choice?
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Loctite 242 for scope mounts?
- Thread starter Miata Mike
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rcmodel
Member in memoriam
It's the ONLY thread locker to use.
Unless you get BLUE grade Permatex or something.
rc
Unless you get BLUE grade Permatex or something.
rc
Miata Mike
Member
Cool! That's what I wanted to hear as I have a good supply from putting my snowmobile suspension back together a while back. 
Strykervet
member
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Let me say first the light blue stuff, or the stuff you have, is the correct stuff. If you look at the bottle, it should say which size threads it works best on, but you can use it in the rails and rings too for a scope mount.
Now that said, I also use the Instabond 124. The stuff never really dries all the way, it turn into a very sticky film, holds up fairly well, and is easier to clean off than the "proper" loctite for smaller threads. The 124 is used to put the lug nuts on a Stryker, it is for larger threads (not all blue loctite is for the same size bolts). This stuff isn't necessarily better, as in stronger, but it does come off easier.
We used it in the army to mount our ACOG's as it was available in every Stryker and the other stuff wasn't (so it was this or nothing). We'd put some on the threads, some on the clamp, and some on the rail as well help keep the mount stay "pulled" to the rear of the particular rails to which it was mounted. We'd use it in the rings on sniper rifles. We also used it on every other thread we encountered because it was all we had. The bottles are big, and the stuff less permament, so you could use a little more than you normally would with the "correct" stuff for smaller threads.
I still have a bottle of this stuff left, it "expired" years ago, but still works just like it did when it was new. I still use it anytime I plan on having to take apart something, like when I mount rails or scopes on rifles that I plan on finishing in the future. But after I finish, I use the appropriate stuff for a better hold.
There is also this new stuff called Rocksett. It is a ceramic industrial adhesive that holds up under high temp. AAC uses it to locktite their flash suppressors. Anyway, that stuff comes out like glycerin and dries like superglue (which is what they compare it to). It is considered almost permanent, but I understand soaking it overnight in water makes it easy to remove. I've never tried it on a scope, plus I've never tried removing it, so I'd definitely test it out first if you try it and figure whether or not it will work for you (for instance, you wouldn't want to submerge wood or most scopes overnight, but the rifle would be okay as long as it was cleand thouroughly and oiled up good after, although I can imagine hesitancy with a nice blue job). If it was easy enough to remove and the water soak didn't pose a problem, this stuff would hold up better than red loctite I think. I think it is worth looking into, and I may try testing it out in the future for holding down rails or whatnot semi-permanently. I may try using it on an FAL scope mount that I want REALLY locked down.
Now that said, I also use the Instabond 124. The stuff never really dries all the way, it turn into a very sticky film, holds up fairly well, and is easier to clean off than the "proper" loctite for smaller threads. The 124 is used to put the lug nuts on a Stryker, it is for larger threads (not all blue loctite is for the same size bolts). This stuff isn't necessarily better, as in stronger, but it does come off easier.
We used it in the army to mount our ACOG's as it was available in every Stryker and the other stuff wasn't (so it was this or nothing). We'd put some on the threads, some on the clamp, and some on the rail as well help keep the mount stay "pulled" to the rear of the particular rails to which it was mounted. We'd use it in the rings on sniper rifles. We also used it on every other thread we encountered because it was all we had. The bottles are big, and the stuff less permament, so you could use a little more than you normally would with the "correct" stuff for smaller threads.
I still have a bottle of this stuff left, it "expired" years ago, but still works just like it did when it was new. I still use it anytime I plan on having to take apart something, like when I mount rails or scopes on rifles that I plan on finishing in the future. But after I finish, I use the appropriate stuff for a better hold.
There is also this new stuff called Rocksett. It is a ceramic industrial adhesive that holds up under high temp. AAC uses it to locktite their flash suppressors. Anyway, that stuff comes out like glycerin and dries like superglue (which is what they compare it to). It is considered almost permanent, but I understand soaking it overnight in water makes it easy to remove. I've never tried it on a scope, plus I've never tried removing it, so I'd definitely test it out first if you try it and figure whether or not it will work for you (for instance, you wouldn't want to submerge wood or most scopes overnight, but the rifle would be okay as long as it was cleand thouroughly and oiled up good after, although I can imagine hesitancy with a nice blue job). If it was easy enough to remove and the water soak didn't pose a problem, this stuff would hold up better than red loctite I think. I think it is worth looking into, and I may try testing it out in the future for holding down rails or whatnot semi-permanently. I may try using it on an FAL scope mount that I want REALLY locked down.
rcmodel
Member in memoriam
Yes, but BLUE Lock-Tight, or good old Blue #242 has been the gunsmith standard for mounts since they invented the stuff.
Why try to reinvent the wheel?
rc
Why try to reinvent the wheel?
rc
Miata Mike
Member
I am going to keep this thread going with a different twist. I mounted my Leupold 2X EER scope using Leupold mount and rings designed for my S&W 629 classic. Every thing went smooth, all surfaces were clean and mated well.
I did not bother to mechanically center the cross hairs before mounting in the rings. After everything was snugged up I borrowed a bore sighter and found that in my basement at 12 yards I was a bit low and left. Windage came over just fine, but I used up all of the up adjustment to get cross hairs to match the laser.
I have not taken it to the range yet to test, so it may not be a real issue yet. Why would it be important to zero the cross hairs on my scope when using a solid mounting system like I am using?
I did not bother to mechanically center the cross hairs before mounting in the rings. After everything was snugged up I borrowed a bore sighter and found that in my basement at 12 yards I was a bit low and left. Windage came over just fine, but I used up all of the up adjustment to get cross hairs to match the laser.
I have not taken it to the range yet to test, so it may not be a real issue yet. Why would it be important to zero the cross hairs on my scope when using a solid mounting system like I am using?
Mac's Precision
Member
I occasionally find scopes mounted with the WRONG stuff....and they use loctite on ALL the screws. I use blue locker on the base screws but I don't lock the rings normally. I have in the past encountered screws that have been installed with the GREEN "Stud and bearing mount". That stuff on a 6-48...is a lot like welding.
dmazur
Member
12 yds may not be far enough. The scope axis is considerably above the bore, and you want the two to be roughly parallel. L/R alignment is important, but if you have the laser dot coincident with the scope in the U/D axis, the bore is really angled up.
One solution I've used is to just measure the distance from the center of the scope to the center of the bore, mark this on a 3x5 card (2 lines spaced that far apart vertically, then another vertical line intersecting both). Tape this up on a wall at a distance the scope can focus on. 20-30 ft usually works. Then turn on the laser and adjust the scope until the crosshairs are at the top intersection while the laser is on the bottom intersection.
Now the scope is parallel with the bore. You can make better adjustments at the range.
I believe most of the concern about "centering" a reticle before mounting is to use adjustable mounts, or rings, to get as close as possible before "using up" the scope's internal adjustments. However, if your mounts aren't adjustable (except by machining), then there isn't much point to centering the reticle first.
Miata Mike
Member
I watched a coworker center the rear Leupold mounts on his rifle with the front and rear rings fully tightened. Now that I think about it, he would have been much better off just using the cross hair adjustment instead of tweaking his scope tube. At the time I never thought about bending the tube of the scope doing this.
This is exactly what I was thinking dmazur. I need to make up some .44 rounds and head to the range tomorrow. The proof will be in the groups.
Miata Mike
Member
2 weeks later and I just made it to the range. Shot 8 inches high at 25 yards, so things are good to go. I guess there was no need to worry about it.
rcmodel
Member in memoriam
Nothing wrong with that.
That's how they are supposed to work.
The way those mounts work is, the front ring is a 90 degree dovetail turned into the base.
The rear has windage adjustment screws.
When you use them to center the retical, the front ring can twist back & forth in the dovetail without tweaking the scope..
rc
Miata Mike
Member
I'm glad to hear the mounts were designed that way. It only makes sense that the front mount would be able to pivot. Thanks for the clarification.
gamestalker
member
I used clear nail polish(stole it from my Wife when she wasn't looking) and it has held without fail. When I've needed to remove things I just use a little acetone and it easily comes off.
Locktite for scope mounts
Looked up Locktite website, BLUE 243(medium hold) is for threads from 1/4 to 3/4 in. PURPLE 222 (low hold) is for threads below 1/4 in.! Did not see that distinction in this thread, but both will work! But may have to special order online, only blue and red available in most DIY stores!
Looked up Locktite website, BLUE 243(medium hold) is for threads from 1/4 to 3/4 in. PURPLE 222 (low hold) is for threads below 1/4 in.! Did not see that distinction in this thread, but both will work! But may have to special order online, only blue and red available in most DIY stores!
rcmodel
Member in memoriam
All I have ever used for 50 years or whatever is good old 'Blue 242'.
It works perfectly on small gun screws, sight dovetails, pins, etc., and still can be removed without heating using normal gunsmith screwdrivers if necessary.
No experience with purple, as I don't see the need.
Red is only if you want to have to use a torch to burn it loose.
rc
It works perfectly on small gun screws, sight dovetails, pins, etc., and still can be removed without heating using normal gunsmith screwdrivers if necessary.
No experience with purple, as I don't see the need.
Red is only if you want to have to use a torch to burn it loose.
rc
Maj Dad
Member
243 is 242 that works in the presence of oil (a little oil, not puddles). I use it on nice guns like my engraved USFA SA 45 from Doug Turnbull that I want to have a little oil on & don't want to degrease the screws (rust is an issue for me ).
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