I typically use Clymer head space gauges for my Savage rifles. I have 223 and 308. I like to stick with what I know but unfortunately, Clymer doesn't mage 220 Swift gauges. My choices look like they are Forster and PTG. The PTG gauges are more expensive. If they're better in some way, I'm ok with that but if they're just more expensive and it makes no difference, I'd rather keep my money.