[Gus Fisher]

For REAL m14 rifles we used to tighten the FS's down pretty tight so they would be good for bayonet fighting. We USED TO tighten FS's down that tight for NM rifles UNTIL we found out that being that tight set up a negative node of vibration in the barrel and hurt accuracy.

It is QUITE common to tighten the FS's down JUST barely snug and use loctite to ensure they won't work loose as fast - circumferentially around the barrel. IOW, the loctite fills the gaps between the FS lugs and the barrel channels for the lugs.

 

[Gus Fisher]

Oh, if one DOES use any kind of Loctite or glue in the barrel channels for the FS. MAKE SURE you put some kind of release agent on the inside of the Flash Suppressor or you may have a devil of a time getting it off in the future. I normally use this:

http://www.associatedindustriesinc.com/store/release-agents/valspar-225-aerosol/

or this:

http://www.brownells.com/.aspx/pid=1045/Product/ACRA-RELEASE-trade-