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Epoxy for bedding a barrel extension
- Thread starter Yote Klr
- Start date
What's the temperature rating of Marine Tex? Locktite 620 is the go to compound for AR barrel bedding.
Yep 250 f ,not good.
I have jb high heat epoxy. Good for 550 f and 4730 psi ?
I have jb high heat epoxy. Good for 550 f and 4730 psi ?
Pressure is contained in the chamber and the barrel held on by the barrel nut so you should be ok there. If the JB is easy to break like the LT620 is, I don't see much of an issue using the JB should you ever have to remove or replace the barrel. Before bedding check the fit between the extension and receiver. If it's a snug slip fit or a thermal fit, bedding might not even be necessary at all. Whether or not bedding is necessary is a never ending debate, there's been a few threads on it. If the barrel to receiver fit is like a hotdog down a hallway, yeah shimming/bedding is recommended. If the fit is a loose slip fit but no real play between extension OD and receiver ID, then use the bedding compound at your discretion.
That's a hell of a lot of taper there. A shim wrapped around the breech and bedding both the shim & front of the extension would be the way I approach that.
That's it? I know someone who repaired the head on their car's engine with it and drove it for years that way. lol
Thermal fit....two dissimilar metals are at play, aluminum and steel barrel extension...
They do not expand at the same amount as the temperature of the components heats up....aluminum expands much faster...causing the joint between them to become looser to some degree, the more heat the looser the fit...probably affects accuracy, as things heat up, the barrel harmonics changes throughout the temperature range of the shot string.
"Something" that would insulate the joint from the steel extension to alum reciever for a longer period of time, would be a better choice, for accuracy, on longer / faster shot strings common in ARs.
They do not expand at the same amount as the temperature of the components heats up....aluminum expands much faster...causing the joint between them to become looser to some degree, the more heat the looser the fit...probably affects accuracy, as things heat up, the barrel harmonics changes throughout the temperature range of the shot string.
"Something" that would insulate the joint from the steel extension to alum reciever for a longer period of time, would be a better choice, for accuracy, on longer / faster shot strings common in ARs.
