.450 Marlin

History

 
The Marlin M1895 in .45-70, released in 1972 has without a doubt been a major success.   Nevertheless, the full potential of this combination has only been possible through hand loading. This is due to the fact that factory produced .45-70 ammunition is loaded to low pressures and velocities for older firearms.  In an effort to create a more powerful off the shelf combination for factory ammunition users, the companies Marlin and Hornady set about creating a new and more powerful factory cartridge. 
 
One design that had already served as a successful wildcat was the 2” version of the .458 Winchester Magnum, normally featuring a 2.5” case.  The design premise was sound however Marlin and Hornady did not wish to adopt this exact design as the 2” .458 posed a risk in that it could easily be chambered in another 2.5” magnum chamber- including .375 H&H chambers.  To overcome this problem, Mitch Mittelstaedt of Hornady designed the new case with a longer belt at the case head. 
 
In the year 2000, Marlin and Hornady introduced the new .450 Marlin.  The initial factory load featured the 350 grain Hornady Flat point Interlock at 2100fps from the full length 24” barreled Marlin rifle, a significant boost in energy over the traditional .45-70 factory loads.  While this combination could have been immensely successful, the high cost of factory ammunition resulted in relatively poor market acceptance. As a hand loading proposition, the .450 Marlin had slightly less powder capacity than the .45-70 due to the heavy case walls so again, sales have been limited. 
 
Presently, the .450 Marlin enjoys limited popularity, mostly enjoyed by staunch fans of Marlin lever action rifles.  To some extent is a pity that Marlin were not able to create a cartridge as powerful as the .458 Winchester Magnum.  Regardless of appeal, ultimately, it is very difficult to produce an affordable cartridge if it utilizes a large quantity of expensive raw materials as all big bore cartridges do.
 

Performance

 
Various authorities have criticized the .450 Marlin as having less power than .45-70 full capacity hand loads by 300fps and up to 500fps. In truth, these differences come about due to variations in rifle barrel length and porting rather than true case capacity.  Case capacity of Hornady .450 brass is around 7 grains water less than Winchester .45-70 brass, a difference of 9%. While 9% more powder capacity should translate into 200fps higher velocity in favor of the .45-70, internal ballistics does not correlate in this way.  In reality, when used in rifles of equal barrel length and loaded to identical pressures, the .450 lags behind the .45-70 by, on average, 100fps.  Major differences only occur when comparing data collected from full 22 to 24” barreled M1895 or Ruger No1  .45-70 rifles with the newer .450 M1895 Guide gun.  As an example, the .450 Guide gun is capable of pushing a 350 grain bullet at 2000fps as opposed to 2300fps in the Ruger No1 .45-70 or 2200fps in the Marlin M1895 with 24” barrel.
 
The .450 Marlin is a versatile short to medium range cartridge, ideal for light through to large medium game and adequate for large heavy game with due consideration. 

When used on light to medium weight game, the .450 loaded with a 300 grain hollow point projectile may produce hydrostatic shock down to impact velocities of around 2100fps, though I have witnessed nervous trauma at lower speeds. With or without shock, internal wounds are extremely broad down to impact velocities of 1700fps, resulting in extremely fast kills.
 
Between the impact velocities of 1700fps and 1500fps, medium weight game animals hit solidly in the chest (including the rear lungs) tend to react in a drunken manner and death almost always occurs within a few yards.  Wounds are broad and fast bleeding. Penetration at these velocities is generally very good.  This translates into a fast killing range of around 175 yards when using 300 grain bullets,150 yards when using the 350 grain Hornady and 125 yards when using 400 grain bullets.  Beyond these ranges, shot placement becomes critical as wounding is proportionate to expanded caliber and game and game may show no sign of being hit and escape considerable distances.
 
As a Moose hunting cartridge, the .450 does its best work when loaded with 400 grain bullets as a means to achieve an ideal balance of wounding versus penetration. The .450 cannot produce nervous trauma trauma when loaded in this manner, but fast kills can still be achieved ou to moderate ranges via careful shot placement (forward shoulder / autonomic plexus).

The .450 is not ideally suited for use on large dangerous game, especially in the hands of inexperienced hunters. Having said this, the .450 can achieve deep penetration and adequate wounding (up to 4x bullet diameter) when loaded with Keith style hard cast bullets. In order to achieve acceptable results, impact velocities should be kept over 1700fps (hydraulic force) with shots placed forwards as a means to break locomotive tissue and bone along with secondary missile wounding effects and also hopefully as a means to disrupt the autonomic nerve plexus.
 

Factory ammunition.

 
Hornady produce two loads for the .450 Marlin, the lightest being the 325 grain FTX Leverevolution bullet at an advertised 2225fps in 24” barrels giving on average 2100fps in 24” barreled rifles and around 1800fps in the stubby 18.5” barreled guide gun.  This is purely a light to medium weight game bullet although several hunters have used it on relatively large game. The FTX bullet is incredibly devastating at very close ranges. But as velocity falls away, this bullet tends to be a mild performer and shows no advantage over traditional designs.  The BC of the FTX bullet is no better than other .354 caliber flat nose projectiles and penetration must be regarded as poor at very close ranges with performance increasing as ranges are extended.
 
Hornady’s heaviest load is the 350 grain flat point Interlock at a true 2100fps in 24” barrels and 1800fps in the guide gun.   This Hornady bullet is a good allrounder for use on light through to large medium game. It is a fast killer and gives deep penetration along with a useful effective fast killing range.  Unfortunately, on large heavy animals, the 350 grain Interlock is prone to suffer jacket core separation and or excessive weight loss.  Even on quartering away shots, the Hornady bullet cannot handle the deflective angle of wide flat ribs resulting in severe bullet upset.  Hornady do not make a heavy game load and it is doubtful whether they ever will, just as it is doubtful that any other major manufacturer will adopt the .450 into their product lines. 
 

Hand Loading

 
With the high cost of factory ammunition, especially outside of the U.S, the .450 has become exactly what its makers had tried to avoid, a cartridge best utilized by hand loaders.  These negative factors were mostly caused by the unforeseen rise in the cost of metals which occurred after the .450 was released. Put simply, without hand loading components, this cartridge would not survive.
 
The .450 is very similar to the .45-70 regarding which powders are most effective.  These include H4198, IMR4198 and ADI2207.   One unique combination is H322 loaded behind heavy 400 grain projectiles and boasts velocities of 2000fps, duplicating .45-70 full pressure, modern rifle loads. Aside from this, average achievable loads from 24” barrels include 2300fps with 300 grain bullets, 2100fps with 350 grain bullets and 1900fps with 400 grain bullets.  Like the .45-70, the .450 loses around 25fps per inch of barrel removed below 24”, in the 18.5” barreled Guide Gun this equates to a loss of around 137fps.
 
Due to the fact that the .450 Marlin closely matches the velocities of the .45-70, readers can refer to that text for a close examination of projectile performance.
 

Closing comments

 
Most hunters are fascinated by rifles capable of firing wide heavy bullets at high velocity. For dyed in the wool big bore fans, the wider and faster the better.  To this end it is a great shame that Hornady and Marlin wasted a golden opportunity to capitalize on this market. A far superior design was the wildcat .450 Alaskan, a cartridge which already had both extensive load development behind it, no patent and maximum tolerable power for use in the Marlin rifle.  The .450 Alaskan is essentially a .458- .348 Winchester Improved, a cartridge capable of near duplicating the .458 Winchester magnum.  The .450 Alaskan also predates the .450 Marlin by several decades, as does the .50 Alaskan of the same ilk.
 
Logic aside, the .450 Marlin is a very capable and versatile close to moderate range cartridge.  With Factory ammunition, the .450 Marlin is at best a small to large medium game cartridge. While some hunters may consider the .450 to be overkill on lighter animals, it must be remembered that in brush situations where shot placement is limited, the wider bores are far more humane killers than many small bores. Using hand loads, the .450 is adequate for larger game providing attention is given to bullet choice, shot placement and safety of the hunter.
 
 

Suggested loads: .450 Marlin					Barrel length: 24”
No	ID		Sectional density	Ballistic coefficient	Observed  MV Fps	ME Ft-lb’s
1	FL	Hornady 325gr FTX	.238	.230	2100	3182
2	HL	Speer 400gr FP	.272	.259	1900

 

Suggested sight settings and bullet paths
1	Yards	50	100	150	200	225	250
	Bt. path	+2	+2.7	0	-6.8	-12.8	-18.7
2	Yards	50	100	125	175	200	225
	Bt. path	+1.7	+1.5	0	-6.8	-11.6	-18.2

 

No	At yards	10mphXwind	Velocity	Ft-lb’s
1	150	6.3	1585.5	1813.8
2	150	6.3	1473	1926

 
 
 

.450 marlin	Imperial	Metric
A	.532	13.51
B	.512	13.00
C	.481	12.21
D	2.100	53.34
Max Case	2.100	53.34
Trim length	2.088	53.04

 
 
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