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British Cartridges
600 Nitro Express
                    "BB" Head Stamp.
Current production using Bertram brass from Australia
Custom Loaded with 900 grain Solid (FMJ) Projectile
The 600 Nitro Express is the  "Largest English*" Cartridge. It was introduced in 1899 in a (2.8" long) and later grew
to (3" long): it was never a Black Powder cartridge. The 600 Nitro Express has a very large 900 grain solid projectile.
* Note:  The 700 Nitro was introduced by Jim Bell, (U.S.A.) and is not technically a British cartridge, although
Kynoch & H&H of  England did also make some 700 Nitro, it was design by Jim Bell in the USA.
For size comparison: Left to right;
.600 NE, .30-30 Win., .22 long Rifle