They do look like it. Maybe I'll try jamming in another one and set it off. (lol) They are hollow though. And I found RBQChicken's old post on removing stuck pellets. The picture he shows of the pellets look a lot like what I've gotten out so far. The streak is maybe 65-70 yrs old. Pellets might have been in there 50yrs? Amazing how many there are. you'd think that after two three, four or five the shooter would realize somethings wrong.
I have used a drill bit glued to a cleaning rod before.I think if I ever did that again today, it would need to be tack welded or something else stronger then super glue. The bit comes off and you'll really have a problem!
I use a 1/8" "aircraft" drill bit like this one to carefully remove stuck pellets. https://www.stewmac.com/luthier-tools-and-supplies/types-of-tools/drill-bits/12-aircraft-extension-drill-bit/?utm_source=google&utm_medium=shopping&utm_campaign=2022-02-gp&gclid=Cj0KCQiAmeKQBhDvARIsAHJ7mF4yVIM-3X5wnxaBlSbSVvYHl1gj6zdf6RLwPzouM2ta0YqQ5_yfvH4aAqjCEALw_wcBI clamp it in a tap handle or maybe in a drill motor and run it at VERY LOW speed.