303 british surplus questions

[mac1911]

So i have had a few boxes of various 303 surplus.
I have noticed they all have a very heavy bullet crimp. New production does not look crimped if so not as heavy.

i understand bullet crimp to prevent set back and such. Although these crimps are pretty stout. Is this to aid in powder ignition or to help build up chamber pressure in the "loose" 303 chambers?

 

[Stape]

Are they old enough to be loaded with cordite? If so, is cordite harder to ignite reliably, thus the heavier crimp?

 

[mac1911]

I can almost be certain it’s cordite

 

[Stape]

I can almost be certain it’s cordite

Pull one down to see? I've only seen pictures of cordite. Looks like spaghetti lol! No experience with it though. Sounds plausible that it has a tighter crimp for reliable and consistant ignition/pressures though.