Shootingtargets7 has the small precision gongs 50% off, I picked up 10-3/8" thick 3"gongs for $51.75 or $5.18 each shipped.. The 3/8 will handle anything I've got to throw at it and even .22 will make them dance.. Coupon code is PG..
https://shootingtargets7.com/steel-targets/gongs/3-8/3-ar500-gong.html
https://shootingtargets7.com/steel-targets/gongs/3-8/3-ar500-gong.html