M3 to KA-BAR Why the change

[Barryeye]

I got my first M3 over 50 years ago and have been a fan of the M3 ever since. I have to ask, why was the M3 replaced by the KA-BAR? Was it a matter of cost or progress to a design thought to be better or both?

[thorin6]

First, there were the 5-inch Mark 1 (Navy) knives and the six-inch hunting knives (Army), almost all off the shelf items, with the Mark 1s being marked and the hunting knives unmarked (other than the manufacturers marks).
Then there were the US Marine's fighting utility knife (7-inches), often referred to as the Ka-bar (for Union Cutlery, one of the manufacturers), the Mark 2 (a Navy production based on the US Marine's fighting utility knife) and the Army's M3. The Navy stopped there, while the Army went to the M4, combining the blade and handle of the M3 with a guard to both be a fighting knife and a bayonet for the M1 Carbine. Eventually the M3 blade became the basis for the M5 (Garand), M6 (M14) and M7 (M16).
That's it in a nutshell; the Ka-bar/Mark 2 was developed and used by the Marines and the Navy; the M3 and its successors was developed and used by the Army.

[dave]

Original carbines were not set up for a bayo as they were meant as replacement for the pistol, more range and easier to shoot well. Not all troops were issued knives, para's were and other special units. Regular infantry were armed with M1's and bayonet for it. The M-3 was for the troops w/o a bayo as regular issue. The Carbine soon became a popular front line weapon and a bayo was developed for it late in the war. The M-3 was the logical one to use. The Navy just went a different route, the M-3 was not "replaced" by the Ka-Bar, they were parallal developements, more or less.

[Barryeye]

Thank you for your very helpful reply. I never realised how the two knives followed thier own branch of the services. On a time line did the army get issued the M3 befor the Marines got the 7 inch Ka-Bar?

[Bayonetman]

Technically the M3 was not replaced by the Knife, Combat, Sheathed. The M3 was modified slightly to allow it to be used as a bayonet as well as a knife by the addition of a muzzle ring on the guard and a catch system in the pommel. The M3 then became the Bayonet- Knife, M4 and the same blade was used on the Bayonet-Knife, M5 / M5A1, the Bayonet-Knife, M6 and the Bayonet-Knife, M7. During WW2 the M4 was issued in place of the M3 when stocks of the M3 were depleted whether it was used as a bayonet or not. Therefore the M3 was not replaced by the Ka-Bar but by the M4 Bayonet-Knife.

During WW2 only the Navy and Marines officially used the USN Mark 2 knife and USMC 1219c2 (commonly called the Ka-Bar by the Marines).

In 1960 the drawings for the knife were updated and new government wide nomenclature of MIL-K- 20277 (Knife, Combat, Sheathed) was adopted. This made the knife available to all branches of the service under a standardized order number. These have been made by Utica, Camillus, Conetta, MSI and Ontario. They are available but my information is that the Army does not make great use of the knife.

Of course the M9 MPBS uses a blade somewhat similar to the Ka-Bar so in a way this represents a transition from the M3 style blade to the Ka-Bar style.

The M3 was officially adopted in January 1943. The Marines adopted their knife in December 1942, the Navy (basically the same as the Marine knife except for markings) in April 1943. In all cases obviously testing, prototypes etc predated the date of adoption by at least a couple of months.

[Johnny P]

The M3 did not make a good utility knife, where the "KA-BAR" type knife was a combination combat/utility knife. From a KA-BAR WWII advertisement in Cole's book:

KA-BAR Sheath Knives are favorites among our Soldiers, Sailors and Marines. Whether they are slasing thru jungle growth, cutting tent pegs or eliminating an enemy, our fighting men have learned to depend on their KA-BARS. These fine, sturdy, well-balanced sheath knives have proved a friend in need to many a soldier.

[Barryeye]

Thank you all for a very comprehensive answer to my question. I am the proud owner of five M3s , a couple of M4 bayonets and a nice Inland carbine.
I collect other knives but by far my favourites are the M3s. For looks and feel I have yet to see another military knife that comes close to them. I acknowledge that the M3 is not as practical for utility/combat as the Ka-bar but I feel the M3 has a strength and character that the Ka-bar lacks.
Barry