The Misunderstood 6.5 Mannlicher Carcano

[Robert Prudhomme]

Let me begin by saying, from my observations, that no element of the JFK assassination is dealt with to a lesser depth than the 6.5 Mannlicher Carcano Model 91/38 short rifle Oswald purportedly used to assassinate JFK. The capabilities (or lack of) of 6.5 Carcano rifles, in general, are usually referred to fleetingly in anecdotal fashion and range from "worst rifle ever...couldn't hit a barn from the inside..." to "it's a tack driver....my Uncle Joe gets one inch groups at 200 yards" and, of course, everything in between. But what if the 6.5 Carcano (its more proper name) was all of these things? Let me explain.

The 6.5 Carcano rifle was developed for the Italian infantry around the new 6.5 x 52 mm cartridge in 1891. It was named the Model 1891 long rifle, and was typical of the long unwieldy infantry weapons of an age not far removed from battling with spears and lances; hence the length of the rifle and equally long bayonet. However, the long rifle also had a long barrel (just under 31") and the Model 1891, produced until 1938, was such an accurate weapon that it is still used in competitions to this day.

Another feature contributing to the accuracy of the long rifle is something known as "gain" or "progressive" twist rifling. Rather than the barrel having a standard number of rifling twists per ten inches from chamber to muzzle, all 6.5 Carcanos up until 1938 had riflings that began at a gentle 1:19 at the chamber and gradually tightened to a 1:8 twist at the muzzle. Although very complicated to machine, this type of rifling was supposedly easy on barrels and made for a very accurate weapon.

Yet another feature contributing to accuracy was the long narrow 6.5 bullet fired from this weapon. With a muzzle velocity of 2400 fps, this long 162 grain roundnosed bullet stabilised very nicely and performed very well, although the round nose and flat base gave this bullet a very low ballistic coefficient not aided by its relatively low velocity and large mass.

At this point, it should be pointed out that, although Italy started out with an excellent weapon, economics, poor wartime planning and, likely the most predominant of all factors, politics, all played a part in contributing to the bad reputation received by the 6.5 Carcano. No sooner had the M1891 been introduced than it was decided to be produced in a cavalry carbine in 1893 called the M1893 Cavalry Carbine. Its barrel was just over 17" in length. Remember the progressive twist rifling of the M1891? These carbines were produced by shortening M1891 long rifle barrels and, of course, the part of the barrel with the tightest riflings (the muzzle) was cut off; leaving the carbine barrel with a maximum rifling of possibly 1:13 which was totally inadequate. Try to imagine what the resulting lack of spin would do to the performance and stability of the 6.5 mm bullet in flight.

The M1891 Cavalry Carbine was produced, along with other carbines, right up until 1938. Of the other three main carbine models, namely the Model 1891 TS (Special Troops), the M1891/24 and the M1891/28, all except possibly the M1891/28 were made by cutting the barrels of M1891 long rifles from 31" to just over 17". As the M1891/28 was an entirely new carbine, it may be possible that new barrels were made for it with closer attention paid to the riflings.

For another example of desperation and compromise in the manufacture of 6.5 Carcanos, we have to go to World War One. The Italians had grossly underestimated how quickly modern warfare churned up men and machines and, at a point somewhere in 1915, it became apparent they were unable to keep up production of the M1891 6.5 mm long rifle to match losses in the field. In desperation, they retrieved their stocks of obselete 10.35 x 47 mm Vetterli Vitali Model 1870/87 rifles. In one of the most bizarre modifications on record, the large 10.35 mm bores of these rifles were drilled out and a liner tube of 6.5 mm calibre inserted into the barrel and silver soldered. The Vetterli magazine was replaced with one to hold the 6.5 Carcano cartridges and, strangest of all, the end of the Vetterli bolt was cut off and a stub for 6.5 Carcano silver soldered onto it! One has to wonder what the final tally of Italians vs. Austrians killed by this weapon was in the end. It was redesignated as the Model 1870/87/15 and, though produced in great numbers, it was kept away from frontline troops and mainly issued to support units, for obvious reasons.

For reasons that had nothing to do with the accuracy of the M1891 long rifle, and which I will go into on a separate thread on the 6.5 mm cartridge itself, the Italians decided, in 1938, to replace the M1891 long rifle with a lighter and easier to handle "short rifle" designated the M1938 or M38 for short. With a barrel length of just over 22", it was quite distinct from the 6.5 Carcano carbines with barrels of just over 17".

A totally new rifle, it also had a newly designed cartridge; the 7.35 x 51 mm. Though not greatly different in length than the 162 grain 6.5 mm bullet, this new bullet weighed only 130 grains. This was due to the spire point on the 7.35, as opposed to the roundnosed 6.5, plus a new development in warfare; mainly the desire to have a bullet topple on impact and cause great grievous wounds. The spire point helped; its pointed tip easily deflected when hitting a bone at an angle. Also, with a spire point, the greatest mass of a long bullet is at its rear and inertia tends to make the back end want to pass the front end on impact. This was further enhanced by replacing the dense lead at the tip of the bullet with aluminum; thus creating an even greater difference in mass from base to tip. The aluminum was covered, of course, by the full metal jacket of the bullet. The aluminum also helped to account for the 32 grain difference in bullet weights.

As the bolt, receiver and magazine of the 7.35 Carcano was still the same as the 6.5 Carcano, the original plan had been to cut short worn out M1891 long rifle barrels, from 31" to 22", and re-bore them for 7.35 mm. Instead of progressive twist rifling, the 7.35 was to have standard rifling of 1:10 from chamber to muzzle. However, poor planning plagued the Italians again, and they soon found themselves at war again with severe shortages; this time being 7.35 mm cartridges. To add insult to injury, they had vast stores of 6.5 cartridges left over from WWI and their African campaigns in the 1920's. One has to wonder about the quality of this aged ammunition but, as they say, beggars can't be choosers.

The Italians took the next obvious step by maintaining production of the M38 short rifle but dropping the 7.35 mm round and going back to the 6.5 mm round. The M38 short rifle was re-designated the M91/38 short rifle 6.5 mm calibre. No record has ever been found that the 1:10 rifling for the 7.35 mm round was ever changed to a more appropriate rifling for the 6.5 mm round of 1:8 or 1:7. Worse, the shorter barrel, designed for the 130 grain bullet, was now being asked to propel a 162 grain bullet designed for the backpressures of a 31" barrel. It is small wonder that muzzle velocities for the 6.5 mm Carcano M91/38 are often given as low as 2000 fps. The lower muzzle velocity further handicapped the rifle's performance as the roundnosed bullet had a lower ballistic co-efficient than the spire pointed bullet and this became more obvious at lower velocities and longer ranges.

Further attributes to the inaccuracy of 6.5 Carcanos (all models) can be traced to the primers used in the standard Italian issue "SMI" (Societa Metallurgica Italiana) 6.5 mm Carcano cartridges. They did not always provide a tight seal and moisture was known to have detrimental effects on the smokeless powder inside the cartridges. Also, the chemicals used in the primers were very corrosive and, in the aged ammunition used by Italy during WWII, primers pierced by firing pins were not uncommon; causing blowbacks in the Carcano chambers. As dealers in surplus Italian arms are quick to point out, surplus Italian 6.5 mm ammunition is highly suspect, for these reasons, and most are quick to advise against firing surplus Italian ammunition.

We have established that the Italians had an aptitude for poor management, compromise and desperation when it came to the manufacture of small arms. I will end this post here, then, and continue with conjectures of what may have transpired between 1938 and Italy's surrender in 1943 in another post tomorrow.

Good night.

Edited June 4, 2013 by Robert Prudhomme

[Robert Prudhomme]

I wasn't sure if posting more instalments on this thread would be acceptable, so Part II of this is on another thread.

[David G. Healy]

I wasn't sure if posting more instalments on this thread would be acceptable, so Part II of this is on another thread.

very nice overview of the MC....

[Robert Prudhomme]

Thank you, sir.