Here is just one Thunderbolt experience I had.
My friend came out to my rifle club with me, bringing his Charter AR7...and Thunderbolts. He’d put 1000’s of rounds of other ammo (non-thunderbolt) through that AR7.
He was sighting in a scope at 100yds. I was shooting my 10/22, using CCI Blazer, my favorite bulk ammo.
I could hear the variations in power when he pulled the trigger.
With that, and his perception of various power levels, he didn’t notice the round that left a bullet in the bore, near the front sight.
The next round blew the squib out, and bulged the barrel, knocking the front sight and the top half of the aluminum cast over the steel bore liner...
I looked over and said, “hey, why did you take the front sight off?”...he was shocked. He disposed of the rest of those rounds, and not by shooting them.
Now, I shoot a lot of rimfire...pistols, rifles, one or both are always with me on range trips. I’ve shot plenty of Thunderbolts in the past, and they were always the worst. Rem Golden Bullets are better..I bought some of those during the last rimfire shortage. They showed up at Walmart, and I bought three milk cartons, in order to save my better ammo. They shot fine.
CCI-anything is great for me. I’m partial to Velocitor and MiniMag. I’ve had good luck with Aguila. Bought a brick each of Aguila Interceptor and SuperMax, their two high speed loads, and they really shot well in everything I tried them in.