Hammer bullets are interesting. The 0.318" 185 gr bullet is recommended for the 318 Westley Richards which I believe takes a 0.330" bullet, not a 0.318" bullet.

Hammer states the following for the .318 Cal-185gr Hammer Hunter™

"Here is a pure copper Hammer Hunter™ for the guys shooting .318 Westly Richards. This will be a great bullet for normal to long range big game hunting."