Bullet Expansion: Velocity Is The Deciding Factor (aticle)

[Chuck]

https://gundigest.com/gear-ammo/bullet- ... C+And+More

[kennyc]

not sure I agree with his views on bullet expansion in animals, by his theory if you shoot a deer with a 300 winmag the bullet will reach full expansion within the body, yet plenty of people have used bullets designed for large game on small Deer and had them pencil through ? velocity was there so where was the expansion ? unless of course the bullet was too hard to expand in that space of time ?
or am I missing something ?

[Laurie]

Expansion is a combination of bullet design/construction + terminal velocity interacting with the target species hide / skeleton / muscular construction plus size. Varmint bullets can act as a regular soft-point expanders at longer ranges / lower impact speeds. Conversely, deer class bullets can prove over-fragile with short range hits and a high performance cartridge giving high retained speeds. (That's why John Nosler designed and made the 'Partition' in his trucking company workshops originally just for his own use - he'd had a series of blow-ups on the hide of an Alaskan moose with short-range shots from an H&H 300 Magnum.)

Some such as the two core RWS and Nosler Partition bullets give dual expansion rates and can cope with a wide range of terminal / impact velocities. Many of today's 'boutique' bonded designs are designed for very-high performance magnums and won't expand at long ranges and/or with shots from lower powder cartridges.

Traditional cup and core RNSP type designs are often very reliable within their design impact velocity bands, but that only worked when there was a much smaller range of cartridges / MVs and when nearly everybody shot most game at very modest distances. Most older 150-180gn 0.30 SPs are designed for mid 20th century 30-06 performance, ie expand fully with high weight retention at 1,800-2,300 fps impact velocity. Many reloading manuals such as Sierra's give design terminal speed ranges for the company's bullets.

For many years in the early small-calibre / smokeless cartridge days when expansion was often unreliable, the near ultimate performer was a well designed 173-175gn RNSP cup & core type in the 7mm Mauser at the original military 2,300 fps loading. The soft bullet expanded well but terminal speeds were such that bullets (mostly) held together. The high SD value saw deep penetration for larger / tougher animals than we have - much loved on large African plains species. Another such cartridge / plain-Jane bullet combination was the 250gn loading in the Westley-Richards 318 Nitro Express, basically the 30-06 case necked-up to take a 0.330" dia. bullet and loaded to 2,400 fps MV. It's still in use in Africa despite being a slow number by today's standards and Kynamco loads it. Karamojo Bell shot many elephants with it even.

https://en.wikipedia.org/wiki/.318_Westley_Richards

However the ultimate marriage of design to MVs are bullets for dangerous game cartridges. Outfits like Woodleigh give very reliable performance (which depending on bullet type can be either nil-expansion / retaining 100% structural integrity through feet of tough muscle and big bones in 'solids' or very reliable expansion in dangerous soft-skinned quarry such as big cats in SPs). For the 450s and above these are designed for use with very modest MVs of 1,900-2,300 fps. Poor performers often become unsellable after word of mouth bad-mouthing, sometimes at former users' funerals. Very high velocity smaller bores often gave lightning kills most of the time but killed their users on those occasions when they didn't work as expected. A well known example was the 280 Ross, a very high-velocity number in its pre-WW1 heyday advertised by its inventor, Scottish aristocrat Sir Charles Ross Bt, as an infallible 'lion-killer' in the sporting versions of his Canadian made straight-pull rifles. Several users discovered the hard way that it wouldn't reliably stop adrenalin charged and angry charging lions.

[Ovenpaa]

Laurie, one of the things we make from time to time but never really advertise are brass 8 Bore cartridges which go overseas. They are used by amongst others a doctor for big cats as they give far more successful results than a rifle, albeit with a lot more damage. I used to have SHED and 8 BORE engraved on the head however I was told not to bother as they were loaded, shot once and discarded which is shocking given the price of the brass alone.

[Pete]

Not much use for trophy hunting, then?

Pete