iāve searched, high and low (eBay, Amazon, etc.). But I canāt find German made SDS bits in 10 mm lots of 3/8ā but thatās 25 thou too small for my 10mm Sierra blaster charges. Sierra sells bits but they are not doing too well. In the super high compressive strength rock Iām dealing with. If Iām lucky I can get 10 inches of penetration per bit. Sometimes they fail much faster. I assume the bit Sierra sells is Chinese manufacturer, but I canāt tell for sure.