Some go bang and some go pop, they have always been like that for me. I'll have to get the chrony out one day measure a box. I had to stop shooting them in my semi rifles and pistols they were soo bad, they are boltgun and revolver use only for me.
Really?
When I got my 22/45 and 10/22 I tried everything I could get my hands on and thunderbolts came out on top. They were the only ammo that would function both 100% and had the least FTF. I get in the neighborhood of 1 FTF in a brick or so.
I have been using them for close to ten years. No issues.
One of the guys at work also uses them in his guns no issues.
Shawn