The best replacement for set screw is cap screw.

The best alternatives to set screw are rated as following:
★★★★★  cap screw
★★★★  clamp gas block
★★★★  compression fittings
★★★  bolt
★★★  pinned gas block
★  clamp on gas block

Your alternative for set screw is not listed? Suggest!
Speaking about set screw, one probably shouldn't forget about ball bearing.

Other search terms related to set screw and their ratings are:
★★★★★ ball bearing
★★ collar
You have in mind a companion for set screw and it is not yet here? Propose!



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set screw
cap screw
clamp gas block