Loctite or Loctite?

[Danube]

I am replacing a set of sights on a old rifle and the package says to use Loctite on the screw when attaching it. I have a couple la' questions though.

Which Loctite to use? I went to a hardware store and they had a selection of the product. For years I've seen people tell people to use it and it photographs of it the Lloctite is blue. At the store they had Threadlocker Blue 242 which is removable and Threadlocker Red 271 which is the heavy duty.

What confused and confounds me is the package reading on the back.

Red Heavy Duty:
To disassemble, apply localized heat to the nut or stuf for 5 min at 450 F. Dissassemble parts while hot.

Blue Removable:
To disaasemble, parts must be broken (sheared) with hand tools.

I would like to be able to remove the sights, not going to but the OPTION of doing so greatly appeals to me. Once in place I dont want to shear the rifle trying to get it off. If I needed permanent sights I would have stuck with an A2 config. Anyhow, the red looks like its the best bet since I can heat up a screwdriver.

Am I wrong here?

My other question is, the sights are going on a rail on an upper. Do I really need to use this product in the first place? Its a 223 not a heavy fire machine gun.

[Clinotus]

I have them both, the wording on the packages can be a bit confusing. When you think about it the 'parts must be broken (sheared) with hand tools' description just means the parts will give with some force. Remember that Loctite is supposed to work that way.

The blue one can be removed with force alone and some patience. This is ok for applications like the one you want to use it on since you do want the option of being able to remove it at some point. This is also the one you want to use for screws that are small.

The red one can be removed with force and extreme heat and some patience. This isn't so ok for the application that you want since its more of a permanent fix as it includes an adhesive. This is the one you want for larger screws..up to an inch I believe.

Separately, those sights will walk off the rifle after a few shots. There is a lot of motion going on when the rifle fires and the weakest point will prove itself after a good day at the range. You really wont damage the rifle at all. Just use a small amount of the blue for your application, making sure first that the area is clean of dirt, debris and oil. A pin drop or so will work wonders and its not that hard to get off later.

Post pics!

[Bob La]

Use Loctite 222 or 222MS.
They are made for parts smaller than 1/4".

EDIT
Here's a place to get it
http://www.rshughes.com/products/079340_22205.html?ref=g&refcp=froogle

[Miso Beno]

Use Loctite 222 or 222MS.
They are made for parts smaller than 1/4".

EDIT
Here's a place to get it
http://www.rshughes.com/products/079340_22205.html?ref=g&refcp=froogle

If you can't get access to 222, aka "purple" Loctite, "blue" (242) will get the job done, but you may have trouble getting enough force on the bit to remove it should you need to make an adjustment. I highly recommend against using "red" (271) Loctite in most situations.