Compared: The .35 Whelen and 9.3x62mm
By Chuck Hawks
The 9.3x62mm was designed by the famous German gunsmith Otto Bock around 1905. Hornady announced in 2010 that they would offer factory loaded ammunition in 9.3x62mm caliber. This means that they will join Stars & Stripes (USA), A-Square (USA), Nosler (USA), Norma (Sweden), Sako (Finland) and Sellier & Bellot (CZ), among others, in recognizing this useful medium bore caliber (9.3mm = .366") that is widely used for hunting heavy game in both Europe and Africa, but less so in North America. Of course, now that a major American ammo company is supporting the cartridge, that may change. In the US, 9.3x62mm rifles are available from CZ, Sako, Tikka, Merkel and possibly others. Factory loaded bullet weights are 232, 250 and 286 grains.
For the edification of his North American readers, Jack O'Connor used to add that the 9.3x62 was much like our .35 Whelen when mentioning the metric cartridge in his books and articles. The .35 Whelen was a wildcat cartridge created in the 1920's by simply necking-up a .30-06 case to accept .358" caliber bullets, without changing the original's 17.5-degree shoulder angle. After decades as a successful wildcat, Remington standardized the .35 Whelen in 1987 and began supplying both rifles and factory loaded ammunition. Federal and Stars & Stripes also offer .35 Whelen factory loads. Factory loaded bullet weights include 200, 225 and 250 grains.
Both cartridges are based on rimless cases with standard .473" rim diameters. The .35 Whelen case measures 2.494" and the 9.3x62 case is 2.441" in length. The shoulder angles are almost identical and the 9.3mm bullet is only .008" larger than a .35 caliber bullet. Both cases can be formed from .30-06 brass and 9.3x62 cases can be created by necking-up .35 Whelen cases in one pass through an RCBS resizing die. The two cartridges are so similar that comparisons are almost inevitable.
The lighter bullet weights in each caliber are designed for shooting smaller game animals, but for hunting the heavy game that is the reason for the existence of both cartridges, it is the heavy bullets that shine. That would be the 250 grain bullet in .35 Whelen and the 286 grain bullet in 9.3x62mm. We will compare these bullet weights in this article.
The 250 grain Remington Express factory load launches a pointed soft point (PSP) bullet at a muzzle velocity (MV) of 2400 fps. The new Hornady load in 9.3x62 uses a 286 grain Interlock SP-RP bullet at the standard European MV of 2360 fps. We will compare these loads in terms of kinetic energy, trajectory, bullet cross-sectional area, sectional density, killing power and recoil.
Kinetic energy is a measure of the ability to do work. Energy powers a bullet's expansion and penetration in a game animal. Bullet penetration and expansion are very important factors in killing power and energy is a useful comparison, as long as similar cartridges are compared. Following are the energy figures in foot-pounds at the muzzle (ME), 100 yards, 200 yards and 300 yards.
Despite its slightly lower MV, the heavier 286 grain 9.3mm bullet gives the 9.3x62 the edge in kinetic energy throughout its flight. This bodes well for killing power, especially on very large or dangerous game animals.
Trajectory is important because the flatter a bullet shoots the less the shooter needs to compensate for bullet drop as ranges increase. The following trajectories, shown in inches above or below the line of sight at the muzzle, 100, 200 and 300 yards, are computed for a 200 yard zero and assume an optical sight mounted 1.5" over bore.
As can be seen from these figures, the .35 Whelen shoots slightly flatter than the 9.3x62, although the difference (0.3" at 100 yards and 0.5" at 300 yards) is unlikely to be significant for big game hunting.
Bullet cross-sectional area
The fatter a bullet is the bigger the wound cavity it is likely to make and the more tissue it destroys as it penetrates. Bullet cross-sectional area is an important factor in wound ballistics. The actual diameter of .35 Whelen bullets is .358" and the actual diameter of 9.3x62mm bullets is .366". All bullets of a given diameter (caliber) have the same cross-sectional area regardless of shape or weight. Following are the bullet cross-sectional areas for our calibers in square inches.
That the frontal area of a .366" bullet is greater than a .358" bullet is understood. The slightly larger 9.3mm bullet should make a slightly wider wound cavity, increasing its killing power, other things being equal.
Sectional density (SD) is defined as a bullet's weight (in pounds) divided by the square of its diameter (in inches). It is important because, other factors being equal, the higher its SD the deeper a bullet will penetrate. Shape (round nose or pointed) has no affect on SD, just the bullet's mass and diameter. Penetration is an important factor in the length of the wound channel and the amount of tissue disrupted. Here are the sectional densities for the bullets used in the loads compared in this article.
Based on its superior SD, as well as superior driving energy, the 286 grain 9.3x62 bullet should penetrate deeper than the 250 grain .35 Whelen bullet. This is important when hunting very large and dangerous game, as it is absolutely critical that the bullet reach the vitals.
There are many ways to estimate the killing power of big game cartridges. Some seem to correlate with observed results in the field and some are simply concocted to promote the author's point of view (extreme velocity, heavy weight bullets, "KO" value, etc.). One of the newer, and better, methods of estimating killing power is the "Hornady Index of Terminal Standards" (HITS), which includes factors such as bullet weight, sectional density, ballistic coefficient and impact velocity. HITS are calculated for a range of 100 yards, a typical distance for shooting large and dangerous game.
HITS scores over 1500 are considered adequate for hunting dangerous game, so the .35 Whelen barely qualifies, while the 9.3x62 has a comfortable margin above that level. The 9.3x62 is clearly preferable for hunting dangerous game. A hits rating of 901-1500 is considered adequate for large, but not generally dangerous, game, such as elk, eland, kudu and moose. Both cartridges are clearly more than adequate for killing large game.
Lower recoil is a big help in achieving proper bullet placement, as everyone can shoot more accurately with a rifle that kicks less. The truth is that all powerful medium bore calibers, including the .35 Whelen and 9.3x62, generate more recoil than most shooters can tolerate in standard weight hunting rifles.
If, as commonly generalized, the average shooter and hunter simply cannot withstand repeated recoil energy in excess of 20 ft. lbs., both of these cartridges are apt to promote flinching. These are not good cartridges for recoil sensitive shooters and even experienced shooters should take them in small doses.
To compute recoil you need to know the rifle weight, bullet weight, MV and the weight of the powder charge. Such computations are approximate, but adequate for our (comparative) purposes. Here are the recoil energy (in foot pounds) and velocity (in feet per second) figures for our comparison loads when fired in 8.5 pound rifles:
As you can see from these numbers, both cartridges are well over the 20 ft. lb. maximum and the 9.3x62 kicks significantly harder than the .35 Whelen. That is the price for throwing a bigger bullet with greater SD at similar velocity. When killing power is increased, your shoulder must pay the price. For large, but not dangerous, hoofed game, the .35 Whelen will get the job done with less pain. It has also proven reliable for killing grizzly bears, jaguar and leopard. If lion, buffalo, rhino or elephant are on the menu, the 9.3x62 is about the minimum cartridge that should be considered for the job. It is also the lightest kicking cartridge legal for use on these animals in most African countries.
Neither the .35 Whelen nor 9.3x62mm are particularly popular in North America, probably because we don't have a lot of game that requires such powerful cartridges. However, both rifles and ammunition are available to the hunter who wants a rifle so chambered and these cartridges are more reliable slayers of big beasts than the popular .300 Magnums, which kick just as hard.
These are versatile and powerful cartridges. If you can stand the recoil, they shoot flat enough to serve as general purpose CXP2/CXP3 class game hunting cartridges and they excel for harvesting large game. There is not a marked difference in their capability unless the largest dangerous game is sought, in which case the 9.3x62mm would be the better choice.
Copyright 2010, 2012 by Chuck Hawks. All rights reserved.