Well, actually, I love helicoils. Timeserts are pretty good, too. I use them both regularly.
But I have also drilled and tapped enough holes in barrels(puckering the entire time) to know that it is a bad idea.
I think tiriaq might be right, the holes look like the tap was just started, and no bottoming tap used.
Hard to tell from a picture.
I have a Love/Hate past with Helicoils, having dealt with various inserts down to around the #2 screw size. I still have some of the custom adapters that I had made over the years for feeding Helicoils in to VERY deeply countersunk holes, as well as some of the mandrels I made for easing the misery of repeated installs of same. And I kept a collection of 'dead' 1/4 inch and 3/16 inch carbide end mills (because you can hand grind one on a green wheel and clean out the remains of a bolt well enough, usually)on hand for some of the uglier removals, usually a stainless bolt, in a stainless part, seized in to a stainless Helicoill...
Keen-serts and Time-serts too. And a couple others, that I am thankful I was not paying out of pocket for...
When they work, they are wonderful. When they don't, see the aforementioned grey hair comments!
Mainly, my problem with the Screw Thread Inserts, aka, STI thread Tap sizes, is that if the thud-f##k that screwed up the original thread gets handed the rework job, he or she has about, in my estimation, 75% or better chance of having learned nothing from the failure, and repeating the same crap that made it a garbage job from the outset!
Sometimes the best solution, from a practical point of view, is to weld up the holes and start over. Or solder plugs in, and do same.
When you are trying to fix someone else's screw up, esp., the difference between being a Hero or a Zero, is sometimes just not leaving it as screwed up as it started, so long as it becomes useful! We did that a lot on some parts, that were unobtainable, so as to make it one or two more inspection cycles.