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Discussion Starter #1
I never used it before. Does it help secure optics on a firearm better than without? Any problems with it ?
 

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If ya use the blue locktite, you will be all good. As limbhangr said, don't use the red. Yer gonna need a cutting torch to get that back apart. LOL
 

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I fpund out the hard way a few years ago that you should loctite your optics on. i had mounted my scope and sighted it in prior to going to camp. once there took it out to shoot a few rounds and ended up shooting almost a box of shells before i realized the scope had come loose. my Uncle was the one who figured it out and told me i should always use it.
 

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Discussion Starter #5
cool thanks all
 

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Machine shop 101

Always use the right tool for the job.

Do not use Red loctite and do not use Blue Loctite.

Red Loctite is not service removable and is not designed to be used on small threads / screws.
Red Loctite is used mainly on threads = bolts 1/4 inch and larger.

Blue Loctite is service removeable - but again is not designed to be used on bolts smaller then a #10

Scope mount bolts is what is called a [censored] Thread.
The reason why it is called a [censored] thread is because it is a ODD thread that has no other use - other then to hold on a rifle scope.

Common threads on a rifle scope is 6-48 and 8-48
That means that the size of the screw is the same as a #6 drill bit or .130 and the screw has 48 threads per a inch.

Rifle scope mount threads requires a special tap, actually more then one tap (3). One to cut the thread and a second to chase the thread and a third - which is called a bottom tap which clears the thread beyond what the first two cut - down to the bottom of the hole.

Let's use 6-48 as a example.
The diameter of the screw is about .130 thousandths.
.125 thousandths is 1/8 of a inch.
We have to drill the hole smaller then the screw so we leave enough material inside of the hole to allow the tap to leave threads inside of the hole, but not so much material that the tap cannot clean out the material being tapped or else the tap would get stuck in the hole and break off - not a good thing.
Lets say that you are going to use a 75% tap, which means that we will drill the hole 75% as large as the finished thread size and will allow the tap to remove 25% of the material left inside of the hole.

For the scope screws to hold with the maximum amount of force, they need about 6 threads or 1/8 of a inch of material.

The only purpose of the Loctite is to fill in the gap between the screw and the treads in the action of the rifle or in the scope mounts themselves.
That gap is .001's of a inch. Not much room for a thick Loctite - which is the reason why we do not use a strong non service removable Loctite or a Loctite that was not designed to be used on small screws.

In order to get a thread locker to work on 6 threads, you need to use a Locquitic Primer. This cleans the threads and makes the Loctite more compatible with the screws.

Because our screws are smaller then a #10, we know that we need to use a special Loctite.
That Loctite in the past was PINK, but now has been changed to a kind of a Purple color.

It's service number is 222 MS
http://www.drillspot.com/products/317523/Loctite_22221_Small_Screw_Thread_Threadlocker

LOCTITE® 7471 Primer T has a 7 day on-part-life, and LOCTITE® 7649 Primer N has a 30 day on-part-life and is Ideal for cure conditions below room temperature.
So, if it's room temp or above and your going install your screws in 7 days or less, use 7471 Primer T. and then the 222 MS.
If your in colder areas use 7649 Primer N. and then the 222 MS
 

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One more key to success is to use the right amount of torque on the screws and to use the right screw driver or Allen Wrench.

A Gun Machine screw has a special slot cut in the head of the screw. That screw requires you to use a Gunsmith screw driver, not a regular old slotted screw driver that you buy at Sears or Lowes.

The Allen Wrench is cut to a certain length so you can only apply so much torque before stripping out the socket head on the top of the screw or bending the wrench.
Usually the Allen Wrench is made from a material that is softer then the head of the screw. So the Allen wrench is designed to strip before the head of the screw.

A real gunsmith will use a INCH LBS torque wrench to set all the screws at the exact same torque.

This is the reason why most people should not attempt to mount their own scopes at home and the reason why so many Gunsmiths makes a percentage of their income from repairing guns where the owner used the wrong Loctite, could not get the screws out, stripped the screws and had to pay a gunsmith to remove the screws for them.

Usually damaging the mounts beyond repair.

Sometimes - you actually have to move the screw holes because the original ones are damaged beyond repair.

Metals hardness is measured on a Rockwell Scale.
A being the softest and C being the hardest.
1 being the least hard and 100 being the hardest measured.

Every time you move up to something harder / stronger on one end, you have to use something harder or better to drill through it to remove it.

Gun Scope Mount screws are sometimes as hard as a 70 C Rockwell hardness.
No off the shelf drill bits will drill through those screws.

We can sometimes machine enough of the screw head off to remove the mounts and leave the screws. Heat the screws and the action - almost cherry red and then let cool.
That usually releases the Loctite and allows a gunsmith to remove the screws with a pair of Vise Grip pliers.

If that does not work, sometimes you can get a Colbalt drill bit or a left handed drill bit or a Carbide drill bit and trick the drill bit to remove the screw for you - in a Bridgeport type mill.

If that doesn't work - you have to move up to a harder cutting tool such as ceramic or diamond.

If the treads are still in the action - good!
If they are damaged, then we have to re drill the hole and re tap them to the next larger size or move the holes to a different location. NOT GOOD!

If you desire accuracy from your new rifle and your new scope - sometimes it is best to pay a gunsmith to do the work for you. Some gun shops such as Grice will mount and bore sight any scope for free if you buy it there.
Even if you take it off one gun and put it on another!
 

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Big Elk is pretty well spot on.

I am often amazed that guys will spend thousands on everything for their rifle, and components and hunts. But they think they are an expert and just plop down their scope on their rifle.

Mounting a scope properly is a time consuming thing to do if you do it properly. If you do not know exactly what you are doing then it probably is best to have an expert do it for a small fee as described above.

As far as Loctite is concerned. I have never used it, and honestly see no need to ever use any type product(like that) when mounting my scopes.

For the average guy he should buy a FAT wrench and torque all the screws as recommended. If done properly-with quality mounts a problem will NEVER arise. Just do it right the first time.

I have both the 1" and 30mm lapping bars, and a FAT wrench. With a hour of time I can mount any scope properly, and NO Loctite needed. Tom.
 

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I use all steel bases and rings and I've never used or needed to use Loctite myself. I think most of the issues with bases loosening up is related to people using aluminum bases on their steel recievers. Eventually the different expansion (and contraction) rates of the two metals leads to a gradual loosening of the base screws.
 

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Mounting a scope if far from scientific, assuming you use quality bases and rings. Better yet, get a set of Talley Lightweights that have the ring and base as one integral unit, or one of the Deadnutz/DNZ mounts.

I couldn't find any stores in the area that carried purple loctite last time I mounted some scopes, so I said to heck with it and used blue. I doubt I'll really notice the difference, though I'm getting some purple for next time.
 

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Big Elk Hunter said:
Machine shop 101

Always use the right tool for the job.

Do not use Red loctite and do not use Blue Loctite.

Red Loctite is not service removable and is not designed to be used on small threads / screws.
Red Loctite is used mainly on threads = bolts 1/4 inch and larger.

Blue Loctite is service removeable - but again is not designed to be used on bolts smaller then a #10

Scope mount bolts is what is called a [censored] Thread.
The reason why it is called a [censored] thread is because it is a ODD thread that has no other use - other then to hold on a rifle scope.

Common threads on a rifle scope is 6-48 and 8-48 8-40
That means that the size of the screw is the same as a #6 drill bit or .130 and the screw has 48 threads per a inch.

Rifle scope mount threads requires a special tap, actually more then one tap (3). One to cut the thread and a second to chase the thread and a third - which is called a bottom tap which clears the thread beyond what the first two cut - down to the bottom of the hole.

Let's use 6-48 as a example.
The diameter of the screw is about .130 thousandths.
.125 thousandths is 1/8 of a inch.
We have to drill the hole smaller then the screw so we leave enough material inside of the hole to allow the tap to leave threads inside of the hole, but not so much material that the tap cannot clean out the material being tapped or else the tap would get stuck in the hole and break off - not a good thing.
Lets say that you are going to use a 75% tap, which means that we will drill the hole 75% as large as the finished thread size and will allow the tap to remove 25% of the material left inside of the hole.

For the scope screws to hold with the maximum amount of force, they need about 6 threads or 1/8 of a inch of material.

The only purpose of the Loctite is to fill in the gap between the screw and the treads in the action of the rifle or in the scope mounts themselves.
That gap is .001's of a inch. Not much room for a thick Loctite - which is the reason why we do not use a strong non service removable Loctite or a Loctite that was not designed to be used on small screws.

In order to get a thread locker to work on 6 threads, you need to use a Locquitic Primer. This cleans the threads and makes the Loctite more compatible with the screws.

Because our screws are smaller then a #10, we know that we need to use a special Loctite.
That Loctite in the past was PINK, but now has been changed to a kind of a Purple color.

It's service number is 222 MS
http://www.drillspot.com/products/317523/Loctite_22221_Small_Screw_Thread_Threadlocker

LOCTITE® 7471 Primer T has a 7 day on-part-life, and LOCTITE® 7649 Primer N has a 30 day on-part-life and is Ideal for cure conditions below room temperature.
So, if it's room temp or above and your going install your screws in 7 days or less, use 7471 Primer T. and then the 222 MS.
If your in colder areas use 7649 Primer N. and then the 222 MS
Pretty sure you meant 6-48 and 8-40 screws, not 8-48. Otherwise, that was a pretty good post.
 

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Been installing bases and mounting scopes for over 30 years and have never used any thread sealant. Have never had anything work loose, either.

I'm even more dangerous now, since I acquired a set of Wheeler gunsmith screw drivers/bits some years back. Before that, just used the same Allen wrenches, torx bits and hollow ground screwdriver bits I made my living with.

The only "thread sealant" I use for things like sling screws or anything else I don't want to come apart, is fingernail polish. Cousin had his sling come apart one year in deer season, so I replaced the missing screw with one from the parts kit I take to camp.

Told his son to go in the house and grab some of mom's nail polish, repaired the sling. Couple farmers pulled up to yak at my cousin, handed him the nail polish and said better put it back before your wife gets home. The farmers decided they'd been there long enough.

 

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I AM WITH DENNYF, I HAVE BEEN MOUNTING SCOPES FOR OVER 10 YEARS NOW, HAVE HAD GUNS AS BIG AS A 375 RUGER AND HAVE NEVER USED ANYTHING ON THE THREADS AND HAVE NEVER HAD A SCOPE MOVE. I ALSO USE FINGERNAIL POLISH, BUT I USE IT ON MY TRIGGER SCREWS AFTER ADJUSTING THEM AND I ALWAYS USE A HORRIBLE PINK I STOLE FROM MY WIFE AND THAT WAY I WILL ALWAYS KNOW IF I HAVE ADJUSTED A TRIGGER AND IT RESEALS THE SEAR AND WEIGHT SCREWS SO THEY DO NOT MOVE.
 

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Got some Atrocious Green and Flaming Orange nail polish.

Mostly use them for iron sights, or sealant. When I bought the green at Walmart, the check out clerk said she didn't think it was "me".
 

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Never use Locktite. and I never have problems sith screws if done correctly. Locktite makes a solid connection between the screw and the threads. If not done correctly it merely sandwiches the base and then it can't be tightened more. The screw can be tight in the threads but the mount can be loose.
 

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Discussion Starter #16
Just for the record, I got the new scope in the mail Wednesday, Leopold Rifleman 2X7X33 and mounted it (Weaver rings and Rail) <u>without any loctite or nail polish</u>. Sighted it in yesterday and the gun shot great and held its mark. 1/2" group at 50 yards about 1" high and a 1" group at 100 yards about 1" high also. Good to go. Thanks for the advice.
 
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