So many 700’s have thread locked on the tenon and heat is better than penetrating oil for that.
You got to it before me
Yes you MUST heat the barrel tenon and outside of action threads with a propane torch to get a Factory 700 barrel off.
Once it breaks loose, Heat it back up AGAIN because the Loctite will start to harden back up immediately as soon as you remove the heat.
I dislocated my shoulder last year removing one when I did not reheat the barrel once it broke loose and was going to put all my weight into the wrench
You dont want that to happen to you thinking "Ahhh its moving now, all I gotta do it just give it a good ooomph and......" dislocate your shoulder
From Last October I'm just starting to be able to do push ups again lol, So 9 months of healing for that one dumb mistake thinking I am stronger than the loctite
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I use ATF all the time in my proffesional shop for loosening bolts and things with heat
ATF with acetone or heck just use regular gasoline as a thinning solvent is as good as Kroil to me.
I dont dillute it because if using heat, it thins out on its own, but that's up to you.
Thinning it works fine if youre letting it soak for hours
But thinning will not do any good to penetrate into sealed loctited threads until heat is applied.
The ATF don't have to be premium Amsoil Synthetic, it can be Dollar Store bargain quarts
When you heat the tenon area, watch from inside the action and the loctite or ATF will start to bubble out
Thats when you know its hot enough to start to loosen it
If it doesn't bubble out, it may not budge yet or will spin in the vise
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Added tip - for a stubborn barrel, put your barrel vise between a press and press it tighter than you can with a wrench on the bolts
I have not had a barrel spin while the barrel vise has been in a 12 ton shop press.
I have also cut Oak wooden blocks and shape them to the barrel and press on those to help prevent galling to the barrel or action