Mediocre results and deforming jackets - Hornady ELD-X Rifle Bullets, 6.5mm, .264, 143 Grain

Compared to Berger bullets, I have not gotten very satisfactory results with the 143 ELD-X in terms of either group size or muzzle velocity standard deviations using either H4350 or H4831SC. ELD-X bullets are also easily deformed during bullet seating by my Wilson VLD seating stem, unlike Bergers. Apparently, the copper jacket is very thin on the ELD-X at the front. In order to stop the deformation during seating, I had to reduce seating friction and force by expanding my case necks with a .264" mandrel (I use a .263" mandrel on Bergers) and lubing inside the case necks. For carrying loaded hunting rounds in my rifle's magazine and subjecting them to recoil, I prefer loading with a little more neck tension than that.