Glock 29 recoil spring

[Mikey1076]

For my G29 using hot ammo such as Underwood and/or Buffalo Bore, would a heavier recoil spring be prudent?
If so, what weight would you folks recommend? 
It is my EDC with Underwood 135gr loads.

Oh and I did pick up a 9x25 Dillon barrel for it recently. 
Does the 9x25 need a heavier spring?   The 10mm loads and the 9x25 loads seem to have the same fpe.
The Underwood 10mm 135gr is advertised at 1600 and their 9x25 125gr is advertised at 1700.  Seem comparable to me, but I don't pretend to know the answer, that is why I am asking the people who know.