Looks like it could be in the genus Saponaria.

I have never grown Bouncing Bet, so I haven't observed it, in all it's life stages. Everything in the pics seems to match Saponaria officinalis, but I question the lengths of the seed capsules. They seem to look longer in pics, but is this how they look after being dead for months? It kind of looks like the outside of the calyxes are covered with a husk before blooming. The dried calyxes have 4 teeth which matches Saponaria and eliminates Silene.

If by Bouncing Bet you are referring to Saponaria officinalis, the pictured plant is definitely not it. I'm very familiar with that species and the whole of this plant is too delicate by far. S officinalis is a fat, juicy thug. Leaf colour, texture and shape of the OP's plant are entirely different and the stems are too thin and wiry.

There's only the 1 Saponaria species in the states. I was focusing on the dried capsules and should have directed more attention to the form. You're right though S. o plants are rather thick and thugish. I thought Silene antirrhina looked similar, except for the seed capsules. There are 29 genera in Caryophyllaceae over here. Argostemma, Arenaria, Cerastium, Corrigiola, Dianthus, Gypsopyla, Herniaria, Holosteum, Honckenya, Loeflingia, Moehringia, Moenchia, Mononeuria, Paronychia, Petrorhagia, Phaulothamnus, Polycarpaea, Polycarpon, Psammophyliella, Rabelera, Sabulina, Sagina, Saponeria, Scleranthus, Spergula, Spergularia, Stelaria, Stipulicita, Vaccaria.

If you happen to be in the vicinity of this plant again, can you get better closeups of the seed capsules and leaves, both sides? Thanks!