No. 

Joe.

I might add that when using CPA's system I wrap the threads with Teflon tape, it helps take up any slack in the threads and it has seemed to be an improvement and it has worked extremely well for me over the years?

teflon tape is a sealer and a gap filler, and also an anti-sieze compound the plumbers use----My dad was one for almost all my life and I worked with hm a fair amount-----it basically prevents water leakage and it helps keep the the connection from rusting shut in case later removal is required.   
I don't know how that all applies to fire arms use, but I don't think of it as a substitute for a precise mechanical fit.
  It'd be interesting to hear what Durren, Taylor, Fewless and some of our barrel-makers think of it.

Thanks Guys,
I guess I was just a little cautious, I haven't worked with many (or any) cast actions.
I don't need the takedown feature and prefer a good solid lock between the parts.

I was taught that Teflon tape lubricated the threads on pipe fittings, allowing the tapers to more easily mate.
Sort of a plumbing aphrodisiac.

To me it would be a "feel" thing. If, as you tightened it, the thought that something was about to break never came into your head, you are probably fine. Recently installed a non original .44-40 barrel on a 44 1/2. As I recall it was tight when I got it properly indexed but nothing that worried me. No idea how many degrees it was off from hand tight. I am thinking more than 10 degrees. It also headspaced fine. Some days you get lucky. As far as Teflon tape, unless you are trying to take up a large amount of slop I would not think it would hurt anything. The threads and the barrel set screw will keep it all together as long as the headspace is right. I used anti seize on mine when they are tight to make sure they come off again. If the fit is slightly loose I would think the Teflon tape would accomplish the same thing while taking up the slop. I have heard of shims being used when the barrel would tighten up too far.

I have use Teflon tape on the barrell threads of my 1993 CPA. It's barrels have been switched a whole lot. Never kept count but perhaps couple dozen times a year.

It makes a slight difference in the way the threads take up. About the same as when the threads are greased or anti sized.  Lately I use Anti Size instead.

CPA or original 44 1/2 systems are in my opinion the best of Rifle takedown methods. Simple repeatable and don't show much wear.  I shoot old double shotguns and 100 plus years later many are loose from being taken down. Common advice with new TD shotguns is light lube, to minimize wear.

Screw tight fixed is a different thing.

Boats