JMO, but those older (60's) Bally games are notorious for House balls. I would say 40% is a bit much, but not unheard of. I own a few 60's Bally's and my biggest offender is my Trio , followed closely by the bus stop then the campus queen. But House balls are the norm.

We must remember these machines were made to make the operator money, so long ball times were not in the operators interest .

I agree with many of the others , make the tilt a bit liberal and Nudge that machine.
I would love to add a doggies to my collection, consider yourself lucky to own one.

Have fun
Brian Lenker
Madison Hts, MI