Greetings Daryl,
All of the postings after mine about using teflon coated patching have valid points, but in my opinion, do not go far enough, and my own comments should have been qualified.
So let's give this a second try, keeping in mind every result is relative to its own set of standards. In my own personal situation, I am a round ball shooter and use barrels that are designed to give maximum round ball accuracy and use Hawken replicas, under hammers, and in-lines; all with barrels rifled for round ball use. ALL of them are used in competition shooting, but only the Hawkens are used for hunting.
I am paticularly fond of 50 caliber and find the 50 to be good for match shooting and hunting in Texas. Our largest big game animal(available to the general public) is the wild ferrel hog. The average buck deer will weigh 110 pounds. South Texas has bigger bigger deer.
Our TMLRA championships are held on the home range in June at Brady, Texas. Conditions are hot, and a day without wind is rare. I usually lose 1 day of shooting or just shoot 25 yards off-hand matches, because the conditions (usually wind) are too bad to do anything else.
My match winning barrels enclude Green Mountain, Getz, Resley, Bresien, H&H(by Hoppy Hopkins, Green River, and a factory Jonathan Browning. ALL are great shooters and WILL win matches if I do my part. Last year the Resley set a new record in one of the 50 yard matches, 50-xxxx. It is a Hawken(10 lbs.) open sights, off the bench.
With all of those qualification stated, Now we get to the subject of teflon coated patching. My material is 0.018" thick 100% Egyptian cotton, washed in hot soapy water, dried on high heat to shrink and draw the fibers up as tight as possible. It is then ready to teflon coat or use with another lube. Teflon fills into the fibers and makes the patch somewhat tougher.
I too, am a ardent swabber. The bore is wiped between every shot with a patch lightly dampened with BLACK SOLVE; 3 strokes on one side, 3 strokes on the other side. Bore size ball in teflon patching will load smooth and easy, but so will patches lubed with OX-YOKE WONDER LUBE or HOPPE'S NO. 9 PLUS. The HOPPE'S is great for cleaning or patch lubing, but too expensive for me in the quanities I use.
For me the great advantage is the consistency from shot to shot during a match on a hoy day. While watching wind flags, and waiting out conditions, the teflon does not change or dry out like in the bore like a water base lube or a spit patch. Besides, on a typical hot June Texas day, I cannot work up enough spit to spit.
Does it really make that much difference? YES! Probably about 3 points or X's. And with the guys I shoot with, giving up 3 points to them will put you out of the running in a 200 or 250 point agg. Our championship state record is 240(with X,s) out of a possible 250. It takes at least 235 to have a chance to win. We have a saying that if you can win at Brady, you can win anywhere. if it was not so far, more of our Texas guys (and women) would be making the trip to Friendship.
Another variable is type or style of rifling. Teflon will generally allow loading a tighter ball without deforming it.My GREEN MOUNTAIN and H & H barrels have grooves wider than the lands and will easily take a .5035 ball with teflon patching as described above. It is not nearly so easy with any other lube, and the ball gets deformed. The accuracy must be seen to be believed. These barrels are preferred for hunting, because if necessary, I can load a second or third teflon patched shot without stopping to wipe the bore.(In anticipation of the question; I have an old Lyman steel mould, .500 size, that cast a .5035 ball).
In most(not all) other 50 caliber barrels, a .500 ball will easily load wiyh teflon patching and give superior accuracy compared to a .495 ball. My wife struggles to load her 50 caliber Browning with a .500 ball if teflon patching is not used. With teflon patching, it loads like a .490 ball was being used.
My Getz and Green River barrels load tight with a .495 ball and teflon patching. A .500 is just too tight, even with teflon.
Is teflon a magical road to instance accuracy? NO! All other components must be right, and the shooter must be capable of good shooting.
Wind and other conditions are a prime consideration to accurate shooting. It is critical to round ball shooting from 50 yards out. GIVEN 2 shooters of equal ability, the one who uses and read wind flags correctly is going to out shoot the one who does not(barring luck of course). This is particulaly true in bench shooting, but also applies to X-stiks and off-hand.
In closing, I will definately state that teflon is a step forward to improving round ball accuracy when all other factors are equal. A bore size ball can be used to improve accuracy and will easily go down the barrel without deforming. However, as shown above by my barrels, what is a bore size ball for one barrel may or may not be for another barrel. Regardless, teflon coating the proper patching material improves accuracy and contributes to ease of loading a tight ball/patch combination.
Best regards, John L. Hinnant