Yes! But a more accurate description would be not keeping them from blowing up, because they don't blow up. Fragmenting bullets simply fragment. If there isn't enough starting mass, they run out of material to continue penetrating (depending on shot placement, impact velocity, and amount of resistance encountered).
The extra mass just allows them to have more mass to allow them to fragment and shed weight but not down to a point they lose forward momentum and stop penetrating too soon.
I've posted about this in much more detail, especially on my own website, but in this forum as well. It's actually been mentioned my many, just not me. Not trying to take any credit away from anyone else.