"Kargan squeezes the bagpipes with his arm."
Translation:DIron qebmeH DeSDaj lo' qarghan.
I can accept the -DI' as another option. And I guess it's acceptable to put Kargan as the subject of either verb. But I think the -Daj is required. While it is true that we might assume that it is his own arm, the English makes it explicit and so the Klingon should as well.
In some languages, it is correct to refer to one's body part with a possessive (his arm). In other languages, it is correct to refer to one's body part with only an article (the arm). Sometimes one of those kinds of languages will go the other way (I hit the captain in the arm).
Klingon appears to work the same way English does. When we get canon sentences linking a body part to someone, they get possessive suffixes. For example, qabwIjDaq Soj tu'lu' There's food all over my face (literally, One finds food on/at my face) (CK). Notice that it wasn't just qab, it was qabwIj. There are other examples.