Agreed.
On many occasions, many people (including myself) took the maximum reported/purported ranges of the DF-17 & DF-27 and slam that value as the label of "everything within that stated maximum range is fvcked" straight away.
However, unlike ballistic missiles which can only travel in straight lines towards their targets, HGVs are designed to evade enemy defenses while travelling at very high speeds towards its target. Unless the enemy can offer no tangible defenses against these HGVs, significant amount of the distances reported/purported as the maximum range of the HGVs are expected to be spent evading enemy defenses, and NOT travelling in the only direction of their intended targets.
Therefore, I believe we need to start rectifying our view on DF-17s and DF-27s WRT their coverage of fire against enemy targets.
Note that FIC = First Island Chain, SIC = Second Island Chain and TIC = Third Island Chain.
For DF-17, the reported (maximum) firing range is 1800-2500 kilometers. Taking the midpoint between the two extremes will be 2150 kilometers.
With around 300 kilometers of buffer distance from the coastline and border, this is what the 2150-kilometer coverage of DF-17 would look like:
View attachment 112078
It is somewhat disappointing that the DF-17 will be incapable of covering the southern end of Bonin Islands (Japan), Singapore and the Malacca Strait. However,
DF-17 practically ensured that everything within and around the FIC Belt can be comfortably targeted from inland China (apart from submarines, of course).
Meanwhile, DF-27's purported (maximum) firing range is around 5000-8000 kilometers. Taking the midpoint between the two extremes will be around 6500 kilometers.
With similar buffer distance from the coastline and border, this is what the 6500-kilometer coverage of DF-27 would look like:
View attachment 112079
Even as the DF-27 will miss Oahu and Sydney, the DF-27 will still be able to comfortably reach targets located as far as Guam, Wake, Palau, Darwin, Pine Gap, Diego Garcia and even Anchorage. In other words, the
DF-27 ensures that everything within and around the FIC and SIC Belts can be comfortably targeted from inland China (again, apart from submarines).
TL; DR - DF-17 is (part of what is) responsible for securing the FIC, while the DF-27 is (part of what is) responsible for securing the SIC. Anything beyond than SIC would be rather straining for the DF-27's operational effectiveness to speculate about.
Last but not least, if China intends to strike targets within and around the TIC Belt comfortably using HGVs instead of ICBMs, then a derivative of the DF-31A/AG will be needed. Perhaps this can be achieved by switching the third stage of the DF-31A/AG with a boost-glide HGV? A 10000-11000 kilometer-range of comfortable coverage from inland China should be feasible.