In the spring of '65, working mineral exploration, I took two pals (for muscle) and a single Otter aircraft on floats across Great Slave Lake (NWT) to recover a small diesel generator left behind when a winter diamond-drill camp closed down.
The drill crew also left behind thirteen 50-pound cases of nitro dynamite, from which liquid nitroglycerine was leaking (i.e.: we are NOT putting this stuff on that airplane!)
I scattered 100 blasting caps around the powder inside one case, and we piled the other cases around/behind it.
Backing off 100 yards, I shot that case repeatedly with a .30-06 rifle.....nothing happened.
Then I tried it with a .44 magnum, hoping that the 'fatter' bullets would have a better chance of hitting a cap. Nada.
You want to see a flinch? Expecting 650 pounds of dynamite to explode on every shot.... THAT will give anyone a flinch!
(I ended-up capping and fusing one stick in one case, a which we lowered into about six feet of water at the pothole's edge. The other cases were placed around it, and I lit the six-minute/ten-foot fuse. A column of water and "loonsh--" went a couple hundred feet in the air.....and came down on the airplane! We had to wash the machine, handing up buckets of water to the pilot, who scrubbed the top surfaces with a broom. Let it be said that he was not pleased. Good thing he was a pal of mine....at least until then.)
Yep, I can EASILY recall fighting the flinch tendency on each shot....a very memorable target indeed.