8mm-06

History

Long before western hunters experimented with the 8mm bore size, Germanic hunters adopted an 8mm-06 of sorts. Wilhelm Brenneke (1865-1951) founded the German Brenneke company in 1895. Brenneke’s main concerns were the development of superior game projectiles to those available at the time in an effort to prevent suffering to game. Designs were followed by serious autopsy resulting in the famous TIG and TUG dual core bullets along with the Brenneke 12 guage rifled slug. Brenneke also pursued an interest in firearms design but besides his famous bullets, he is best known for his cartridge designs. Noting the successful design of the US .30-06 Springfield cartridge, Brenneke explored the potential of the .30-06 case necked up to 8mm for hunting use as well as a proposed upgrade for the military M98 rifle. The military cartridge concept was unsuccessful however as a hunting cartridge, Brenneke’s 8x64S was well received.
 
The 8x64S Brenneke was officially introduced in 1912. It remained popular for several decades but in later years lost favor to the universally accepted .30-06 cartridge. Nevertheless, the 8x64S made a small comeback after the Brenneke company released its TOG bullet (core bonded) which they tested in 8x64s. That said, brass cartridge cases and factory loaded ammunition are currently difficult to find outside of Germany. Germanic hunters have enjoyed the 8x64S which many rate as having the power missing from the 8x57JS for large medium game without the recoil of the 8x68S. The 8x64S has a slightly smaller head diameter than the .30-06 but is slightly longer in base to shoulder and total case length than the parent .30-06 case (.30-06 cases can be used for fire forming). In German literature the US wildcat 8mm-06 is acknowledged and referred to as the 8x63.5.
 
After the Second World War a mass influx of surplus German military 8x57JS M98 Mauser rifles became available to western hunters. US shooters were aware that although 8x57JS brass was rare, cases could be formed from .30-06 brass, trimmed and fire formed to size. But this was no one step process. To this end wildcatters created the 8mm-06 based on the .30-06 necked up to 8mm with no other changes. Hand loaders were then able to make use of full length .30-06 brass, making the exercise of fire forming cases much easier - with added power over the 8x57JS thrown into the bargain.
 
The 8mm-06 became popular for a time throughout the U.S, Australia and New Zealand. The wildcat achieved velocities averaging 150fps and sometimes 200fps higher than the 8x57JS. In its heyday the 8mm-06 was most spectacular when loaded with the Norma 165 and 196 grain Vulcan PPC bullets.
 
In the past the 8mm-06 has been given such labels as the poor man’s magnum due to its ability to launch heavy bullets at relatively high speeds. In truth, the 8mm-06 did start life as a budget hunting option based on Sporterized Mauser actions. But as time passed it became apparent to all that U.S bullet manufacturers were concentrating on optimizing .30 caliber bullet designs. The .30 caliber bullets had extended range capability, performing well in multiple roles while 8mm bullet designs remained stubby and stunted.
 
Today the 8mm-06 survives to some extent as a nostalgic curiosity, maintaining a small following. That said, those who use the 8mm-06 develop an immediate respect for its potency. The 8mm-06 may not be the most popular cartridge, but it is not to be underestimated.
 

Performance

 
The 8mm-06 draws a direct comparison with the parent .30-06 cartridge. The 8mm-06 typically produces velocities 50fps greater than the .30-06 with top loads in some rifles achieving up to 100fps greater velocities. Unfortunately the BC and SD of 8mm bullets are on average 17% less efficient than their .30 caliber counterparts and within 150 yards, the faster driven 8mm projectiles have dropped to .30-06 velocities.
 
Bullet diameter of the 8mm is only 5% greater than the parent caliber resulting in a 10% increase in bullet frontal area.  And while a 10% increase in frontal area may sound good, there is little in the way of real world differences in the field based on this aspect alone. However - the reduction in SD can be used as a means to increase energy transfer. Having said this, it would be foolhardy to suggest that any sacrifice in BC compared to the .30-06 is fully balanced and repaid for by an increase in energy transfer as in many instances, the differences are very subtle.
 
Thanks to new bullet designs, the 8mm-06 is just now coming into its own. This cartridge can be used with great effect on light framed game, is extremely potent when used on mid weight game and can tackle very large body weights with heavy weight bullets. Of course, the parent .30-06 has always been praised for these virtues. Regardless, loaded hot, fast and heavy, the 8mm-06 is a true powerhouse, especially when used within moderate ranges. When used in situations where the decreased SD and increased energy transfer can be taken advantage of, the 8mm-06 can quite simply produce spectacular performance.

   

Factory Ammunition

Due to the fact that the  8mm-06 is a wildcat cartridge, there is no factory ammunition available for this chambering.
 

Hand Loading

The 8mm-6 is a simple cartridge to work with. Obviously, parent .30-06 brass is easy to source. Reloading dies are readily available from RCBS and Hornady’s custom line. Suitable powders for reloading the 8mm-06 are the faster burning 3031, H4895/ADI 2206H with 150 to 175 grain bullets, through to 4064 and ADI2208/ Varget with 200 grain bullets. Comfortable velocities are 3050-3100fps with 150 grain bullets, 2850fps with 170-175 grain bullets, 2800fps with the 180 grain Ballistic Tip and 2600fps with 200 grain bullets. Some rifles can achieve velocities 50fps faster than listed here, higher velocities tend to cause very poor case life, alluding to excessive pressures. 
 
The standard reamer design of the 8mm-06 calls for a long throat and due to the 84mm (3.307”) internal magazine length of the M98 action, bullet jump is normally around 4mm (.157”). Nevertheless, accuracy is generally unaffected in the same manner as the .308. Some decrease in bullet jump can be obtained by either using the modified 175 grain Sierra Prohunter or via the use of European bullet designs. Short throating is possibly not highly desirable due to potential velocity loss.
 
Due to the fact that the full range of 8mm projectiles is described in detail in the 8x57JS section, the ahead text will focus on some of the more useful 8mm projectile designs. For further comparisons, please refer to the 8x57JS.
 
The 150 grain projectiles produced by Sierra, Speer and Hornady are fast Killers on game in the 40 to 80kg (88-176lb) weight range out to 150 yards. Beyond 150 yards, velocity falls below 2650fps, limiting the potential for hydrostatic shock. From 150 yards onward, the softer Hornady bullet is noticeably faster killing than its competition and to some extent, the most effective bullet of the 150 grain offerings. But for tougher animals, the 150 grain Speer is the best choice due to its ability to maintain integrity during penetration. The 150gr Speer is best used where game body weights are of great variance, from very light animals through to mid weight game weighing up to 150kg (330lb).  None of the 150 grain 8mm bullets give great penetration, capable of quartering but not tail on shots on game weighing up to 80kg (176lb). It is possible to run these bullets at up to 3150fps without high pressures but stability is sometimes an issue due to the fast twist rate of Mauser barrels versus the long bullet jump.
 
Of the medium weight bullets, the 170 grain Hornady round nose bullet is well suited to light to mid weight game species at bush / woods ranges with the ability to reach out across small clearings without losing too much velocity. This is a very soft bullet which derives great benefit from increased velocity over the 8x57JS cartridge, ideal for snap shooting with some room for shot placement error. The 170 grain Speer Hotcor is a tougher bullet, best suited to Mule / Red deer through to Elk sized game, doing its best work out to moderate ranges of around 230 yards. Beyond this range, wound channels are much smaller and killing can be somewhat delayed.
 
The 175 grain Sierra is a clean but slow killer when used on light framed game, doing its best work on game weighing between 90 and 320kg (200-700lb) out to a range of around 280 yards, beyond which killing can be delayed. Generally speaking, this bullet should not be used beyond 300 yards. In the past, I have run loads as hot as 2980fps but this velocity is right at maximum and some rifles will not handle these speeds, producing poor accuracy and limited case life. In rifles which allow such muzzle velocities, the 8mm-06 appears vastly more potent than the .30-06 (without taking BC’s and downrange performance into account). These occasional high velocities are possible with individual rifles as a result of both the increased bore diameter and the difference in freebore in comparison to the .30-06 versus individual chamber and bore tolerances. However and generally speaking, the 8mm-06 is much happier at milder velocities. On the other hand, I have yet to try Hornady’s Superformance powder in the 8mm-06.
 
The 175 grain Sierra can be modified to increase performance across a wider range of body weights by filing off the lead tip and drilling a small hollow point into the core (see 8x57JS). While experimenting with bullet seating in my own 8mm-06 some years ago I filed the lead tips off the 175 grain Sierra bullet when experimenting with COAL. I then decided to hollow point the Sierra as a further experiment. The irony of the 171 grain “homemade hollow point”, is that although the BC is reduced to just .274”, where the 175 grain bullet fails to produce hydrostatic shock beyond 80 yards, the 171 grain bullet produces high shock and very fast killing out to ranges of up to 400 yards - though wind drift is a concern.
 
In time 8mm users will have use of the new Hornady 170 grain SST bullet. This will hopefully be one of the best things to happen to the 8mm bore. It is hoped that the 8mm SST will be a spectacular killer, ideal for game weighing up to 150kg (330lb), possibly at its absolute limit on game weighing 320kg (700lb) with an estimated effective clean killing range of 700 yards. The 8mm SST will most likely be the go-to bullet for 8mm users in the future.
 
The 180 grain Nosler Ballistic tip driven at 2800fps is slightly too heavy for lighter medium game. Out to 75 yards, shots that strike shoulder bones result in fast kills while shots that strike behind the shoulder can produce delayed killing, though internal wounding is broad and kills are clean. The Ballistic tip is better suited to game weighing between 90 and 200kg (200-440lb) and is capable of handling quartering shots but not tail on shots. Loaded to 2800fps, velocity drops below 2650fps within 75 yards therefore fast killing on game in the 90 to 180kg range cannot be expected beyond this range if rear lung shots are taken. Despite potential delayed killing, the Ballistic Tip is capable of producing clean killing with both front and rear lung shots on lean game out to ranges of around 250 yards, its low SD also working in its favor. Beyond this range, speed of killing can be much slower and is greatly dependent on shot placement. On larger bodied deer, the effective range can be extended to around 430 yards (1800fps), especially with select shot placement and in this regard, the 180 grain Ballistic Tip has merit.
 
Both Barnes currently produce two medium weight bullets, suited to large, tough bodied medium game, the 160 grain TTSX and 180 grain TSX. Of these, the TTSX bullet has great merit for large bodied deer. If one observes the business activities of Barnes over the last decade, it is painfully obvious that in order to optimize performance, Barnes have steadily introduced light weight bullets as a means of ensuring full energy transfer. The wide hollow point behind the polymer tipped TSX continues this trend. Penetration has never been an issue with Barnes bullets - only energy transfer, regardless of hype. To this end, it must be understood that the 160 grain TTSX gives nothing away to its heavier 180 and 200 grain heavyweight counterparts unless hunting very large, heavy bodied game. Both the 160 and 180 grain bullets should be driven as fast as possible to aid trauma. From a muzzle velocity of 2950fps, the 160 grain TTSX does its best work inside 260 yards (2400fps) and is capable of producing very wide internal wounding. Between 2400fps and 2200fps, wounding remains broad but killing can be delayed. Below 2200fps or 360 yards, wounding tends to be narrow and more proportionate to caliber resulting in delayed killing. Whether shooting in close or out long, shot placement is the key to success with the Barnes bullets, aiming to strike shoulder bones in order to effect fast killing.
 
Heavy 200 to 250 grain 8mm projectiles are ideal for game in the 180kg to 450kg range. The 8mm-06 launches these bullets at a velocity of 2400fps to 2600fps which is too slow to expect exceptionally fast killing but with select shot placement excellent results can be obtained. Hot 200 grain loads driven at 2700fps do make a difference in speed of killing out to 50 to 75 yards but case life is often limited as previously described.
 
The 200 grain Speer Hotcor designed for the 8mm Remington Magnum expands readily and fully at 8mm-06 velocities. It produces a broad wound channel but can be a slow killer on lighter game. The Hotcor is best suited to game weighing between 90 and 320kg, reliable on cross body and quartering shots but not tail on shots, retained projectile weight is generally between 145 and 152 grains. When used on large heavy game, the Speer loses more weight and cannot be relied on to penetrate onside shoulder bones.  The Speer is simply outstanding when matched appropriately to game weights and used at close to moderate ranges, a true hammer of Thor.
 
The 200 grain Nosler Partition gives deeper and more reliable penetration than the Speer, suited to game weighing between 90 and 450kg (1000lb). The Partition readily sheds frontal area which aids both wounding and penetration. The Partition is most spectacular inside 200 yards but can be put to use out to a range of 350 yards, producing fast killing with careful shot placement, directed to break shoulder bones. For large bodied deer, Antelope, Bear and Moose, the 200 grain Partition is a go-to bullet.
 
Another excellent bullet is the 196 grain Norma Vulkan, ideal for Red / Mule sized deer through to animals weighing up to 450kg (1000lb) at close ranges. As a woods hunting bullet the heavy Vulkan can be quite spectacular in action. It is possible to push the Vulcan out to ranges of around 250 to 300 yards but its true forte is up close and personal. The Vulcan does not produce deep penetration and is not on par with the Partition bullet - but it does produce very fast killing on larger bodied deer.
 
Where game of up to 450kg and above are likely to be encountered, the 200 grain Barnes TSX is capable of producing exceptional penetration. Nevertheless, penetration alone does not ensure fast killing. It is important to understand that as game weights broach 450kg and head towards the 600kg (1300lb) mark, both the 8mm bore and Barnes bullet design pose limitations. On game up to the size of Moose, it is important to break bone in order to effect fast killing. On heavier game, neck or head shots are the go. Ranges should be kept short in order to maximize energy transfer and wounding potential. 
 
Woodleigh produce three useful heavyweight bullets for the 8mm-06, the 196 grain round nose, 220 grain round nose and 250 grain round nose. And if you did not get the hint, these are round nose bullet designs which in the Woodleigh line, do display a marked difference to their protected point bullets. In my experience over the years the Woodleigh round nose bullets offer the ultimate balance of deep penetration versus expansion for energy transfer on large bodied game. Some folk prefer a bullet that retains more shank (like the deep penetrating Woodleigh protected point) but it is impossible to fault the balanced performance of the Woodleigh round nosed bullet.
 
For tough, heavy bodied game, the Woodleigh has no peer. Stalk close and aim for bone - this is the way to utilize Woodleigh bullets. Nevertheless, it has to be reiterated that the 8mm is not a big game bore. On heavy game weighing between 450 and 600kg (1000-1300lb), either utilize neck shots or adopt a larger bore for the sake of the animal. With that said, the Woodleigh maximizes the potential of the 8mm bore on large bodied game, used at close (woods) ranges where velocities compliment the bullet design. The faster these bullets can be driven, the better.
 
One final bullet to consider is the Hornady 196gr HPBT Match bullet. With its meplat trimmed to expose the hollow point, BC is around .500. This can be utilized as an extended range load for larger bodied deer weighing over 90kg (200lb) to 320kg (700lb) with an effective range of around 500 yards. 

Closing Comments

 

While the 8x64s Brenneke has made a small comeback in Germany, the western 8mm-06 wildcat has maintained a small following. When the .325 WSM was introduced I wondered if this might kill off the 8mm-06 altogether but instead, it fueled the fire and if anything, the 8mm-06 has held equal ground to the new Winchester cartridge thanks to new .325 WSM component projectiles.
 
For those who own original Mauser rifles in good condition chambered in 8mm Mauser - I would urge readers to refrain from re-chambering to 8mm-06.  M98 8mm Mauser rifles in very good condition are not so common. Sure, there are many that look good on the outside but the bore should be of equal concern. Instead, the 8mm-06 should be seen as an option for pre-sporterized 8mm rifles or rifles assembled from surplus parts, such as the occasional pile of used VZ barrels that turns up via a collector / importer shipment.  
 
The 8mm-06 is certainly a potent, hard hitting cartridge. It may not have the range of the .30-06, but it can hold its own at ordinary hunting ranges and as new bullet designs emerge, this dark horse has plenty of surprises.   
 
 

Suggested loads: 8mm-06					Barrel length: 24”
No	ID		Sectional Density	Ballistic Coefficient	Observed  MV Fps	ME Ft-lb’s
1	HL	150gr Interlock / Speer	.205	.290	3100	3200
2	HL	170-171gr hollow point	.233	.274	2850	3084
3	HL	170gr Hornady SST	.233	.445	2850	3066
4	HL	200gr Partition / Speer	.274	.350	2600	3002

 

Suggested sight settings and bullet paths
1	Yards	100	150	267	305	325	350
	Bt. path	+3	+3.7	0	-3	-5.1	-8.1
2	Yards	100	238	274	300	325	350
	Bt. path	+3	0	-3	-5.9	-9.3	-13.3
3	Yards	100	150	255	294	325	350	375	400
	Bt. path	+3	+3.5	0	-3	-6.1	-9.2	-12.6	-16.6
4	Yards	50	100	221	257	275	300
	Bt. path	+1.8	+3	0	-3	-5	-8.2

 

No	At yards	10mphXwind	Velocity	Ft-lb’s
1	300	10	2175	1576
2	300	12.1	1928	1411
3	400	12.7	2078	1629
4	300	10.4	1901	1604

 

 

8mm-06	Imperial	Metric
A	.473	12.01
B	.470	11.94
C	17 deg
D	.436	11.07
E	.349	8.86
F	1.948	49.48
G	.388	9.1
H	2.494	63.34
Max Case	2.494	63.34
Trim length	2.840	63.04

 
 
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