The 35 Whelen is simply a 35-caliber version of the 30-06 case. In 1988, Remington standardized this long-time wildcat, which, contrary to what gun-writers had claimed for most of the 68 years since the original version in 1922, was indeed the brainchild of Colonel Townsend Whelen. Don’t believe everything you read, even if I wrote it! Without reducing body taper and increasing shoulder angle, 35-caliber is the largest feasible bore size for the 30-06 case. Even at 35-caliber, headspace control is marginal, at best. When chambered in a gun with significant striker energy, such as the 1903 Springfield (which was the rifle most commonly converted to 35-Whelen) headspace control is borderline. Because of this, either excessively annealing case necks or installation of a heavier striker spring will result in potentially dangerous case shoulder setback upon striker impact. Subsequent case stretching can result in case-head separation with the potential for a catastrophic gas leak with a destroyed rifle and an injured or dead shooter, bystanders, or both! In modern rifles with factory cases, headspace control is adequate but handloaders need to be aware of this potential issue. With its narrow, shallow-angled shoulder, ammo makers have long known the 35 Whelen has marginal headspace control. They were cautious about neck annealing. Likely best practice with the Whelen is to not anneal the necks. Just reuse the cases until the necks get too hard and then start with a new batch. Better safe than sorry. This is an instance where Remington could have done itself and everyone else a favor by adopting the Ackley Improved version of this round. With less body taper and a sharper shoulder, headspace control is 2.7-times greater. This is generally sufficient to entirely solve any headspace control concerns. Loaded with properly constructed bullets, the 35 Whelen is entirely capable for taking any game anywhere on earth. Recoil is far more manageable than the recoil generated by most of the recognized stopper rounds used against the biggest, and most dangerous animals, so it is a fine choice for recoil sensitive hunters wanting the most power they can handle. Heritage of this case dates to the 1870s with the introduction of the 40-70 Ballard case.