Some of my jar lids are doing this. 1/2" headspace, put in hot water bath and processed for 10 minutes. Any ideas?

Looks like to much heat but I’m no expert

Never experience that happening

Hard to imagine too much heat, that's why you use a water bath

Could be faulty lids

Bad rings or lids. I do a lot of canning and I have never seen that happen.

Rings too tight would be my guess. Heated air can't escape and bulges the lids like that.

Wife says bad lids

My wife is thinking the same....new lids on new jars may be the culprit

I have seen that a few times, mostly when I go to gorilla on the bands.

Hard to tell from the picture but is that a one piece lid? I have never had that problem with two piece lids.

Ball's been putting out some pretty crappy lids. Either you tightened it too much, or it's just a junk lid.

rings to tight

I got some bad "lids" back in the ,70's....it's was a 4 fingah of mexican

Got some generic wide mouth lids from Amish store couple years back. About 1 per dozen had that bulge. Problem seems to be bad fit. When lid heats up it expands and metal has to go somewhere, so it puckers up. Solution seems to be finger tight only..........and pray there is still enough force from screw so that it sucks down to seal. That may be far less than we know. But if it doesn't seal, run it thru again.

But only $15 bux! Can't go wrong!

Two piece.

Yep.

ring too tight. I try to use just 2 fingers to tighten rings.

To much pressure.

Rings too tight. That's what I think as well