Headspace gauge

[Scoots]

Just about wrapping up my build, so now it's time to check the headspace.

The barrel is an Oly from Del-Ton in .300 Fireball. I know a lot of you purchased brass from Keith Davis, as have I. I believe his brass is trimmed to 1.355" to ensure that the cartridge will chamber.

So - will .221 Fireball go-no-go headspace gauges be what I need to use to accurately check the headspace in my .300 Fireball???

Thanks for your help.