Help - remove set screw w/ Loctite 272 on it

[GyroF-16]

As the title says - I’m not able to find a way to remove a gas block set screw that I treated with Loctite 272. It’s the high-temp stuff, and sure seems like a good idea at the time - since the gas block can sure get hot.
I’ve tried a heat gun, a butane lighter, and super glue solvent. I’m starting to twist the end of the Allen wrench hex key that I’m using. And afraid that I’ll stop the screw.

Background - this is on a PSA 8” 300 BLK upper that seemed like a bargain at about $300 shipped. The gas block was leaking, and I had to remove it at reseat it properly. It worked fine for about 400 rds, until this week I removed it to try to swap the barrel nut to affix a slightly different PSA handguard. The factory-installed barrel nut was so tight / seized that I gave up and made a slight modification to the existing nut to get the new handguard to lock down properly. Despite paying close attention, I evidently induced another leak when reinstalling the gas block. There was obvious gas residue on the barrel and inside of handguard after 60 rds today, so I started to take it off to re-seat to properly. The forward set screw came out with a little persuasion, but the aft on (the one that rests in a divot in the barrel) isn’t moving.

Any ideas? This upper is starting to be much more trouble than it’s worth.
Any suggestions on a higher-quality 7.5-8” upper? I’m eyeing Aero, but am open to suggestions. Does anyone make chrome lined 8” 300 BLK barrels?

[Default.mp3]

I guess use Rocksett next time? You might need to take a torch to the gas block. 272 is suppose to be removed at 250 °C/482 °F.

https://blackrivertactical.com/WP/BR...BLK-p440556374 is a good barrel option, I would think, given BRT's reputation. Most options I know of are 8.5" (Faxon, Criterion CORE, etc.).

[Spartan1980]

Maybe a pencil type soldering iron directly on the screw? Mapp torch might be needed. It does take some heat to break the bond. In aerospace manufacturing, I never reinstalled so I don't know if the bond reestablishes upon cooling or not. We used a fair amount of thread locker and over a dozen variations of catalyzed epoxy RTV type sealants. All of them are pretty stout.

[JCN]

I’m a big fan of Rocksett.

For loctite stuff I use a Brûlée torch. Able to get more heat on it than a traditional lighter.

[Exiledviking]

I bought a soldering iron for just this purpose. Not sure if it'll work for you, but worth a try.

[littlejerry]

Map torch and impact driver with high quality bits. Get it hot, hit it with the impact.

I've done a few gasblocks that way with no problems.

[Suvorov]

I’ll bring my torch next week.

[GyroF-16]

Thanks for all the suggestions.
I have a soldering iron- I’ll give that a shot tomorrow.

And lesson learned on the Red Locktite. I’ll stock up on Rocksett, since I’ll likely be pulling the SF3P (again) to either swap the barrel, gas block, barrel nut, or all of the above.

@Default.mp3 I also appreciate the barrel suggestions. I’ll be doing the math on paying the gunsmith at my range to just cut the existing gas tube and swap the barrel nut and barrel/gas system for a higher quality option. I assume the ‘smith has access to an impact rod and a better vise than I do.

And there’s still the option of the $420 complete upper from Aero.

[SecondsCount]

BCM makes a chrome lined 9" 300 BLK barrel but show out of stock.

[littlejerry]

Thanks for all the suggestions.
I have a soldering iron- I’ll give that a shot tomorrow.

And lesson learned on the Red Locktite. I’ll stock up on Rocksett, since I’ll likely be pulling the SF3P (again) to either swap the barrel, gas block, barrel nut, or all of the above.

@Default.mp3 I also appreciate the barrel suggestions. I’ll be doing the math on paying the gunsmith at my range to just cut the existing gas tube and swap the barrel nut and barrel/gas system for a higher quality option. I assume the ‘smith has access to an impact rod and a better vise than I do.

And there’s still the option of the $420 complete upper from Aero.

In my experience the soldering iron is pissing in the wind. You have a lot of steel there which is dissipating that heat faster than your dinky soldering iron can manage. You need combustion. Put a mapp gas torch on it, hold it there till you see smoke from the threads, then hit with an impact driver.

Half measures result in broken screws and rounded heads.