I think the bullet was too light for caliber, didn't match whatever spin was needed for the weight, and maybe, as a cast bullet, wasn't even quite the right diameter. Not to mention the powder might have been too fast and the charge too high.
I've not seen a .270 bullet weight that low ever since; the lowest I've shot since has been 100 gr.
All I really can tell you it was a once-and-done experience.
PS: I posted this before I read Unclenick's post; he said it better than I did.
