I have used FP-10 for years as a rust preventative and lubricant on several different types of firearms.  I generally use a small amount.  I have just acquired my first AR.  I lubed it according to the USMC Operator's Manual specs, using FP-10.  It is pretty oily inside, which I do not mind.  But, I am wondering...  Does Breakfree dry and leave just the teflon, or does it stay oily like FP-10.  Seems like a dry film would attract and hold less grit.  I will use FP-10 anyway as I all ready have it.  But is this any reason to switch?

BF does dry up eventually leaving a film.  FP10 is good as well and alot of folks here swear by it.  Personally......for an AR either will do your job just fine.

FP-10 is a slightly thicker oil and has no solvents.So it does leave a thicker film of oil on the surface and does not evaporate or run off nearly as fast as the Break Free.
I find that exceptional especially for storage.
So thats why you have a longer lasting, wet surface with the FP-10.
In my opinion FP-10 is a much much better lubricant in every way.
If your wanting a drier surface just wipe off the excess FP-10 after lubricating leaving a thin film of oil just as you would the Break Free.
I use an application brush to apply FP-10 to my firearms.I put a few drops of FP-10 on the brush tip and spread it around.That leaves just the right amount/thin film on the parts.Really makes the outside of an AR look good too.
The new Break Free has a higher content of oil so it will also stick around a little longer than it has in the past,but it still evaporates rather fast.
Like Horik said either will work just fine.
But in my opinion FP-10 is the best clp to use on any weapon.
FP-10 also will not attract dust unless you leave a very heavy film of the oil on the surface.The same goes for Break Free.
Just wipe off the excess FP-10 leaving a thin film and your good to go.
I found that out in my last Colorado hunting trip.
Raymond

Blankwaffe98, FP-10 doesn't have any solvents? Breakfree must not either then, right? Both FP-10 and BF are CLP's, so they both clean. IMO, FP-10 cleans better than BF. Or you could just ask George, the maker of FP-10. He is a member of ARF.com. Man I love this site! [:D]

Hickboy,
I have asked George and he says no solvents in FP-10.He uses a base "oil" that works like a solvent but that is not one.Check the MSDS and you will see no solvents listed also.
Check here,he mentions it.
http://www.ar15.com/forums/topic.html?b=3&f=7&t=174832
Hickboy if you want a ton of information and alot of reading go to:
http://www.1911.com
Do a search on FP-10 and start reading.
Break Free does use solvents.
Later.
Raymond

Hickboy,
Here is one George did today about FP-10.
http://www.1911forum.com/forums/showthread.php?s=&threadid=65669&perpage=25&pagenumber=2
Raymond

Thanks Blankwaffe98!!