Disappointing braid breaking strength

I was tying and pulling on some of my braid line and it seemed to break too easily so I decided to test it with my scale. I tied double surgeons loops on each end put one end on a screwdriver held in my vice and the other on my scale. Then I pulled slowly looking at the weight on the scale until the line snapped. The result was surprisingly low so I bought a different brand of higher test braid from Amazon and tried that. Again, disappointing. I then tried some mono lines that were in my garage for a couple of years and it were mostly right on.

The results:
Brand and test: breaking weight lb (multiple tests)

Braid lines

KastKing Superpower 40#: 20, 24, 22

Magreel Suburb 65#: 30, 31, 33, 34

Mono lines, all Berkeley Trilene

15#: 17

20#: 25, 19

30#: 27, 30

50#: 39, 44, 40

Since knots make the weakest point, I did a few tests by just wrapping the line around rather than tying proper knots. That only increased breaking strength a small amount.

I know those are cheaper braid brands, but they both broke at only about half the rated strength. When I look at the reviews on Amazon for all braid lines I notice that there are some complaints that the lines break too easily. I wonder if this is optimistic rating that can only be demonstrated under perfect laboratory conditions or what. If you have to get braid rated twice the strength to get what you want, then you lose the advantage of having a thinner line.

ive always used powerpro b 4 i bought a kayak never had an issue

Daiwa Samurai J braid is excellent. VERY consistent and 8 strand instead of the usual 4. There are several test videos on Youtube that verify it has very good breaking strength. Don't let the relatively low price deter you either, this is high quality line.