need cartridge identfied please.

[ruddersrangers44]

Can someone tell me what the smaller cartridge is against the .303,it has L42 stamped,thanks in advance......

[PhantomGuitar]

Looks to me like a 7.62 NATO Round produced by Radway Green in the UK. I believe 05 is year.

[Scout]

7.62x51 NATO most likely. MIL version of the .308 WIN.
Ive fired untold thousands of these (bolt action, semi-auto, MG) and its one of my favourite rounds.
If I had to make do with only one calibre, it would be a .308/7.62x51.
In this case there is not much doubt, but if you supply measurements, it can be established without a shadow of a doubt (if not now, then in case of the next round you find. No pun intended).
Compare your round to below 7.62x51 schematic:

[ruddersrangers44]

Thanks guys,my son was given it by his Grandfather,nice to see he's taking an interest in my hobby.........

[TonyE]

It is a British 7.62mm Nato made by Radway Green (British Aerospace) in 2005.

The headstamp tells you all you need to know. It is a L42A1 ball round which is sniper/competition quality and is loaded with a 155 grain boat tailed bullet. It was superceded by the L42A2 and then the L42A3 round.

Regards
TonyE