What is the strongest loctite?

What is the most strongest loctite available?

Im guessing you need this for the barrel shroud on your TX200. I would talk to an airgunsmith and see if they can drill and tap the barrel shroud and secure it with screws.

Yes! I’m not sure I want to deal with a gunsmith. Not sure if there are any and where to find them in my area. I’m in NorthCal. Plus, they charge a bit.
 
Red requires a few hundred degrees of heat to break loose. Blue and PURPLE are the main ones for what we would normally see uses for with airguns. Purple is the only one I use on any smaller screw or bolt. Blue is usually too strong for small fine threads and you will end up stripping allen heads. For anything .25" or larger, then I move on to blue. 
 
What is the most strongest loctite available?

Im guessing you need this for the barrel shroud on your TX200. I would talk to an airgunsmith and see if they can drill and tap the barrel shroud and secure it with screws.

Yes! I’m not sure I want to deal with a gunsmith. Not sure if there are any and where to find them in my area. I’m in NorthCal. Plus, they charge a bit.

Any one of these would work:

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Like @motorhead said, 640 & 680 are permanent "retaining" compounds. The only issue is they do not cure easily in areas with limited air (non-anaerobic), longer set / cure times, and they're not gap filling. If the parts are very air tight, then it can take over a month for them to cure (if ever lol).

271 is strong, but messy. I normally use 268 in its place (it's in a lipstick-like form).

Personally, I would use either 268 or 638 (638 is my go-to most of the time). Just be advised that 638's set time is very fast so preparation is key so you can work quickly.