Thread: "Air space" in 303 British and 308 Winchester caseloads...Dangerous?

The extra air gap wont be a problem in that situation.
There is a risk of the powder detonating rather than burning in very reduced loads tho....like less than 60% case fill.
Rule of thumb is the bore diameter of engagement but in reality nowhere near this is required.
If you have a good 3-4mm contact in the neck you should have no problems in a bolt action.