xausa:

Generally, yes, I've found that to be true, but there are exceptions of course. There are many late BPEs with front sight ramps, and some early full nitros with low ramps. The only reliable way to confirm original, full Nitro Express proof on the British guns are marks on the flats indicating the full Nitro Express load for the cartridge. Relying on anything else, including a Nitro Proof mark, can easily lead to use of incorrect ammo, and a damaged or blown gun.