The solid pole is just a special case of the hollow pole where the inner diameter, d, is reduced to 0.
Example 1 - your ‘old’ tube:
A tube of outer diameter D=152.4mm and a wall of 3.98mm will have an inner diam, d=144.44mm...
Putting these numbers into the formula above, should give a max bending moment of
MY=1368kpm before taking a permanent bend, and
MB=1676kpm before breaking
Example 2 - your ‘new pole’,
The outer diameter, D=177.8mm and wall of 3.98mm gives inner diam. d=169.84mm
Putting these numbers into the same formula, should give a max bending moment of
MY=1883kpm before taking a permanent bend, and
MB=2307kpm before breaking.
Now, it is almost midnight here, so I suggest you double-check the numbers.
The reason why my results are more conservative than yours, is probably because another value of material strength, Sigma, has been used.
Conclusion: I now think it is better to go for the thickest, ‘new’ pole with MY=1883kpm (if my calculations are right...)
Cheers,
Arne