I just started leather crafting and bought 3 pro line chisels from Tandy leather. I found the holes made by 1-prong chisel is bigger than those made by 2-prong one, which makes bigger hole than 4-prong one no matter how hard the punch is. The prong spacing is the same for all three chisels (88044 series). Is this normal? I've never used chisels of other brand, so I've no idea. Please, some suggestions for good chisel brand available in the states.
Also I found stitching groover is hard to work on thin leather to make straight line. Is the groove a must? Is there any alternative that's less likely to fail?