.256 Newton and 6.5-06

History

Charles Newton has often been described as the father of high velocity. As a cartridge designer, Newton was born well ahead of his time in an era lacking in slow burning powders for his large capacity cases.  Nevertheless he designed some very potent cartridges as well as patenting several experimental bullet designs. During the period in which Newton was involved in designing the .22 Savage Hi Power, it appears that Newton had doubts about the Hi Power's suitability for the medium game it was intended for. With it's 70 grain bullet at 2790fps these doubts became well justified.

Newton continued to experiment with case design and in the same year (1912) that the Hi Power was released, Newton developed a hotter wildcat. The .22 Newton was based on the .30-06 case shortened by 1/4 inch and necked down to fire a 90 grain .228 caliber bullet at 3100fps. But the wildcat would not satisfy Newton and he immediately had other ideas for a high velocity small bore deer cartridge. The .22 Newton was put on the back burner and received no further attention until his friend, gunsmith Jerry Gebby started to explore its possibilities (see .22-250). Within a year, Newton had developed a cartridge based on the .30-06 necked down to 6.5 (.264") with a 23 degree shoulder. In 1913 Newton released his new cartridge the .256 Newton.

Initially ammunition was loaded by the Western Cartridge company who offered a 129 grain bullet at 2760fps. This was about as fast as powders of the day could drive bullets in the .256 and it would not be until the 1940's when slow burning powders would come onto the scene. The .256 was well received by the shooting public but in 1914 a new and more pressing situation arose - war. Committed to the First World War, the American army was forced to take over Newton's factory. By December of 1917, Newton had used the last of his stock of shells and projectiles and with no components or access to machinery, there was no market for his rifles. Newton eventually managed to borrow more money for extra machinery and by January 1918 had retooled up. In April of the same year the bank foreclosed on the loan and Newton's company went into receivership. The .256 remained factory loaded by Western until it finally dwindled into obsolescence in 1938.

After the second world war, an influx of surplus Swedish Mauser’s reintroduced U.S hunters to the 6.5 caliber. With .30-06 brass more readily available than 6.5x55 brass it was natural that many 6.5 rifle barrels were put onto longer actions and reamed to the wildcat 6.5-06. 

The 6.5-06 and .256 Newton are very similar in outer appearances but the Newton does feature some differences in comparison to the simplistic 6.5-06 design. The .256 Newton has greater body taper, the base to shoulder measurement is shorter as is the over all case length. However shoulder angle is slightly sharper than the 6.5-06 at 23 degrees. In turn, the 6.5-06 is slightly longer in case body dimensions, has less body taper, but retains the parent .30-06 gentle 17 degree shoulder angle. Case capacity of the Newton is slightly lower than the 6.5-06.

Both the .256 and 6.5-06 have retained limited popularity and although rifles are no longer chambered in .256 Newton, some excellent examples have survived to this day.

The 6.5-06 has gained merit as a general medium game hunting cartridge, as a long range hunting cartridge and as a long range target shooting cartridge, excelling in all three roles.

 

Performance

Due to twist rates, the .256 Newton does its best work with bullet weights of up to 130 grains and with modern powders, it is possible to achieve velocities of between 3000 and 3100fps with 120 grain bullets and 2900 to 3000fps with 130 grain bullets. The 6.5-06 is is capable of driving 120 grain bullets to velocities of 3100 to 3150fps and 140 grain bullets at 2900 to 2950fps, the .256 and 6.5-06 are flat shooting, hard hitting, fast killing cartridges. That said, it would be foolhardy to suggest that these 6.5’s have a ballistic advantage over the .270 Winchester within ordinary hunting ranges. Out to 300 yards, the 6.5’s and .270 slow down at an identical rate. A major difference in performance occurs when the 6.5’s are used specifically for long range match shooting and hunting. The 6.5’s can be loaded with match bullets which have much higher BC’s than .277” projectiles. Bullets such as the sleek 140 grain Hornady A-max and 140 grain Berger have extremely soft jackets which maximize wounding at longer ranges - and are extremely violent between 200 and 500 yards. These factors make the 6.5’s somewhat unique.

The 6.5 caliber has been used over the last century to take a vast amount of large heavy game but such use does not work towards the strengths of this bore size. The 6.5’s are at their best on light to medium weight game and driven at high velocity do their work in a spectacular, emphatic manner.

   

Factory Ammunition

No Factory ammunition is produced for either the .256 Newton or 6.5-06 wildcat.
 

Hand Loading

Reloading Dies are readily available for both the .256 and 6.5-06. A form die (RCBS) is required to form Newton brass from .25-06 or .270 cases while 6.5-06 brass is easily formed in one step utilizing .25-06 brass which shares near identical body dimensions.

The .256 Newton has slightly less case capacity than the 6.5-06 however 6.5-06 book data (ADI / Hodgdon) can be used for both cartridges due to the already mild nature of data given. H4813sc is an outstanding powder for the 6.5’s. Realistic velocities for the .256 Newton from 24” barrels include 3000 to 3100fps with 120 grain bullets, 2950-3000fps with 129/130 grain bullets and up to 2900fps with 140 grain bullets.

The 6.5-06 is capable of driving 120 grain bullets at velocities of 3100 to 3150fps, 140 grain bullets at 2900 to 2950fps with the ability to launch heavy 160 grain bullets at velocities of around 2700fps. Optimum twist rate for custom rifles is 1:8.

The comments made in the 6.5x55 section about bullet performance are just as relevant here, regardless of the extra velocity produced by the 06 length case. Soft conventional projectiles weighing between 120 and 140 grains do not produce deep penetration on densely muscled game due to theoretically high SD’s. Projectiles such as the Interlock, Pro-Hunter, GameKing, Ballistic Tip and Hotcor are best suited to lighter framed deer species.

The .256 Newton rifles typically featured 1:10 twist barrels, ideal for 80 to 120 grain bullets while 130 grain bullets are to be considered the upper limit. Accuracy with 140 grain bullets vary from rifle to rifle along with potential muzzle velocities. Occasionally, a slow twist barrel will yield better bullet stability when heavy bullets are driven fast. Yet by the same token, in some instances rifles must be heavily downloaded before any degree of accuracy is obtained. 

A trio of the most useful medium game hunting bullets for the .256 include the 120 grain Nosler Ballistic Tip, the 120 grain Barnes TSX and 125 grain Nosler Partition. All three are excellent performers. The 120 Ballistic Tip produces identical wounding to the Hornady A-Max bullet at impact velocities above 2200fps with internal wounding up to 2.5" in diameter, ideal for light to mid weight deer species. The 120 grain TSX does its best work above 2400fps and is able to tackle larger bodied deer with ease. The 125 grain Partition is an outstanding general purpose bullet for light, through to mid weight deer species.

The core bonded 129 grain InterBond, 130 grain Accubond and 130 grain Scirocco bullets all give excellent results in the .256/6.5-06. From muzzle velocities of 3000fps and above, results are emphatic. On medium game, the core bonded projectiles not only produce wide wounding but in most cases, the projectile creates a very fast bleeding exit wound even though the exit wound may only be .75” in diameter. Best performance occurs inside 275 yards, beyond which, all three gradually lose their ability to create wide internal wounds. As ranges exceed 300 yards, it becomes imperative to take extra care with shot placement towards breaking major bones. These projectiles will take large bodied game but again, such use is not working with this cartridge’s strengths.

Useful bullets for the 6.5-06 include the 120 grain Barnes TSX, the 140 grain Hornady SST, the 140 grain Nosler Partition (my personal go-to bullet) and the 140 grain A-Max.

For the toughest animals, nothing comes close to the Barnes TSX 120, 130 and 140 grain TSX and TTSX bullets. Readers are however reminded that although penetration with these bullets can be exceptionally deep (deep enough to take Bovines through both shoulders), wounding characteristics of the 6.5mm caliber are not optimal for game of this size. Of the three Barnes bullets, the 120 grain TSX (and TTSX) can prove the most useful for hunting medium game. Heavier Barnes bullets can at times display a tendency to cleave to momentum. An admittance of this can be seen by observing Barnes manufacturing trends and the ongoing introduction of light weight bullet options including the 100 grain 6.5 TTSX (untested at this time of writing). In truth, the 120 grain TSX produces similar performance to the 140 grain TSX when both are used on Elk sized game. The lighter bullet produces greater trauma and adequate penetration, the heavier bullet produces deeper penetration and really only comes into its own on heavily raking shots.

The 140 grain Hornady SST sees an increase in its already good performance when utilized in the 6.5-06  as opposed to the 6.5x55. Not only is wounding dramatic but also, high impact velocities cause the SST jacket to swage into itself after expansion which helps lock the jacket and core together. The 140 grain SST driven at 2900 to 2950fps produces wounding that is much more diffused and disproportionate to caliber than is possible with the Swede when used at range. The Swede loaded with the SST begins to show a drop in performance on medium game past 200 yards (2400fps). On smaller deer species, the differences are mostly undetectable but on tough animals, there is a definite loss in killing power and shot placement becomes more critical. In the 6.5-06, this range is extended to 310 yards.

As mentioned in the 6.5x55 text, the 140 grain Nosler Partition really is an extremely good bullet. The Partition has a BC of .490 and loaded to 2950fps, is adequately suited to taking shots on medium game as far as 550 yards (2000fps) slightly further at a push (1800fps), a very good all-rounder. This bullet has the soft, violent, fast expanding features required for long range work yet is extremely reliable at point blank range. The 140 grain Partition reaches the limits of its excellent performance on Elk sized game. On larger animals, it is possible to ask too much of this bullet design and although the Partition will often produce fair results, ball joints (4" in diameter) and heavy bone (2.5 to 3" diameter) can cause bullet blow up.

For long range hunting, the 140 grain Hornady A-max (BC .550) is capable of producing wide, extremely violent wounding on mid sized deer species down to 1800fps. 

 

Closing Comments

The use of the 30-06 case (or lengthened 8x57 case, depending on ones demographical background) as a base for building 6.5 caliber cartridges, is as popular in Europe as it is elsewhere. Germany's 6.5x64 Brenneke and 6.5x65 RWS follow similar case dimensions to the .256 and 6.5-06. The most recent of these, the 6.5x65 was released in 1989, based on Dynamit Nobel's (owner of RWS ) realization of the need for a modern 6.5 to fulfill the demands of the German hunter. 

With a growing trend towards strong, light 90 to 130 grain controlled expanding bullets scribing ultra flat trajectories, the 6.5x65 case utilizes all available powder capacity with a shoulder over 4mm (.157" ) further forwards than other 30-06 based 6.5's, creating a short neck. In turn, rifles chambered in 6.5x65 have shorter throats than 6.5's of old which utilized long 160 grain round bullets. Instead the 6.5x65 chamber is designed with a decrease in bullet jump, enhancing accuracy with lighter bullets. The 6.5x65 is able to achieve realistic velocities of 3200fps with 120 grain bullets and 3000fps with 140 grain loads duplicating the wildcat 6.5-06 Ackley Improved.

Although I have listed the .256 and 6.5-06 together, the two cartridges differ slightly in dimensions and should not really be treated as the same. More correctly, the .256 Newton is the historical forerunner to the 6.5-06. I have suggested some very high velocity loads for the .256 but in truth, those who own vintage rifles may want to run mild loads to minimize wear and preserve these wonderful examples.

The 6.5-06 is an excellent cartridge and somewhat under utilized, having distinct advantages in comparison to the .25-06. For its mild recoil, the 6.5-06 delivers excellent extended range performance and is not so heavily reliant on high impact velocities as its .25 caliber near twin. The 6.5-06 is an extremely good choice for light weight female shooters with established rifle skills, wanting maximum performance combined with tolerable recoil.

 

Suggested loads: 6.5-06					Barrel length: 24
No	ID		Sectional Density	Ballistic Coefficient	Observed  MV Fps	ME Ft-lb’s
1	HL	120gr Nosler Bal Tip	.246	.458	3150	2643
2	HL	120gr Barnes XLC	.246	.381	3150	2634
3	HL	129gr InterBond	.264	.485	3050	2664
4	HL	130gr VLD	.266	.595	3050	2685
5	HL	140gr Nosler Partition	.287	.490	2950	2705
6	HL	140gr Amax/SST	.287	.550	2950	2705
7	HL	140gr VLD	.287	.640	2950	2705

 
 

Suggested sight settings and bullet paths
1	Yards	100	175	290	332	350	375	400	425
	Bt. path	+3	+3.8	0	-3	-4.6	-7.1	-10	13.3
2	Yards	100	175	285	325	350	375	400	425
	Bt. path	+3	+3.8	0	-3	-5.3	-8	-11.2	14.8
3	Yards	100	165	280	322	350	375	400	425
	Bt. path	+3	+3.7	0	-3	-5.7	-8.4	-11.5	14.9
4	Yards	100	165	285	328	350	375	400	425
	Bt. path	+3	+3.7	0	-3	-4.9	-7.4	-10.3	-13.5
5	Yards	100	150	268	310	350	375	400	425
	Bt. path	+3	+3.5	0	-3	-7	-10	-13.4	-17.2
6	Yards	100	165	272	312	350	375	400	425
	Bt. path	+3	+3.6	0	-3	-6.5	-9.4	-12.6	-16.2
7	Yards	100	165	275	318	350	375	400	425
	Bt. path	+3	+3.6	0	-3	-6	-8.75	-11.8	-15.3

 
 

No	At yards	10mphXwind	Velocity	Ft-lb’s
1	300	5.5	2567	1756
2	300	6.7	2458	1610
3	300	5.4	2509.5	1803.6
4	300	4.3	2604.5	1957.8
4	750	30.2	2012	1169
5	300	5.5	2426	1829
6	300	4.9	2480	1912
7	300	4.1	2543	2010
7	725	27	2026	1276

 

 

256 Newton	Imperial	Metric
A	.473	12.01
B	.470	11.94
C	23deg
D	.423	10.92
E	.290	7.37
F	1.900	48.26
G	.411	10.44
H	2.450	62.23
Max Case	2.450	62.23
Trim length	2.440	61.9

 

6.5-06	Imperial	Metric
A	.473	12.01
B	.470	11.94
C	17 deg
D	.442	11.23
E	.298	7.57
F	1.948	49.48
G	.321	8.15
H	2.494	63.35
Max Case	2.494	63.35
Trim length	2.484	63.05

Note:  For the 6.5-06, custom cartridge dimensions may vary individually from the above. SAAMI specifications for the 6.5-06 have in recent years been ratified by the A-Square rifle company.
 
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