Gyvel...bolt action rifles are also tried and true. I don't know about you, but a self loading rifle with a 20 round magazine capacity is better than a bolt action rifle with 5 shots in most fights.
We're not talking about rifles. We're talking about a device that you carry (maybe concealed) on your person in polite society. I will take anything that has proven itself over time if my life depends on it over some oddball attempt at gimmickry. Technology is one thing, but gimmickry is another.
Additionally, we had rifles that featured 20 and 30 round magazines in a little conflict I was in called Vietnam. All it accomplished was the "spray and pray" technique. I forget the actual statistics, but it was somewhere in the "thousands of rounds expended per 1 VC casualty."
On the other hand, the British, who carefully trained their riflemen, and who utilized 10 shot bolt action rifles for decades, had a far greater casualty to expended round total in two major world conflicts, plus Korea.
So don't tell me a 5 shot bolt action rifle is any less effective in any kind of fight than a 20 shot semi, or a bizarre, curved pistol is any more effective than a proven conventional design. It's how you utilize the weapon you have and how you discipline yourself.
Edit: Curved barrels are not new technology; The Germans tried it in WWII, and possibly someone before that. it's just an old idea that the current generation has either forgotten or never heard of. Didn't work very well for the Germans...