That would be a cleaning rod, not a ramrod. The Peabody actually was #1 in the trials for a breech loading rifle following the War Between the States as I recall. The Springfield was picked because it could be converted from existing rifled muskets & just perhaps the fact that it's designer, Erskin Allen was a Springfield Armory employee may have had some influence, reckon??
Peabody also had a design & patent I believe on a hammerless model but most folks weren't quite ready for it just yet. It is a somewhat sad story, that on the majority of guns built of his basic design, his name was completely eliminated, Martini taking first place & then Henry for the rifling.