Gentlemen,
Lets not forget what rifles you want to use these solids in. If you use these "modern solids' in your old English doubles you run the risk of the rifling appearing on the outside of the barrels. Therefore always measure bore diameter before using. They are not very forgiving!
Best solid in my mind, for classic English doubles is the Woodleigh range, they are the right shape, construction, and are very accurate. I will be able to report on deformation when I return frm Zim. in July
Also dont forget to load them back a little, due to increased pressure.

Eric