Why the 6.5mm Carcano Rifle was Labelled Inaccurate

[RobertP]

The term "Humanitarian Rifle" for the 6.5mm Carcano rifle was actually begun by Italian troops and the inspiration for this name had nothing to do with accuracy. Jacketed bullets were introduced in the late 19th Century as rifles evolved from large bore, low velocity weapons into small bore, high velocity weapons. As the bores got smaller, and velocities higher, unjacketed lead bullets were found to quickly foul the riflings of the smaller bored barrels, and the copper alloy jackets prevented this. However, as the jackets were full metal jackets, it was quickly discovered that a jacketed bullet went straight through a person without inflicting a lot of damage, as opposed to the earlier large-bore unjacketed chunks of lead bullets that deformed and splattered easily in a wound and did LOTS of damage. This problem was made even worse by the long narrow design of the 6.5mm Carcano bullet, making it into a "flying drill". Ideally, a bullet should tumble in a wound, making a big mess, but the Carcano FMJ bullet greatly resisted this. Short bullets destabilize and tumble in wounds MUCH better. Hence, the "Humanitarian Rifle" name. To show just how great this problem was, the British Indian army, in sheer desperation, issued the "dum dum" bullet. This was the .303 British Mk. III cartridge and was essentially the original round nosed bullet with the nose of the jacket removed, exposing the lead core. This was actually the first soft tipped bullet. Later developments in the Mk. IV and Mk. V were actually the same bullet but with a hollow point this time. As all of these designs were expanding bullets, they had far greater stopping power against native tribesmen than did the full metal jacket bullets.https://encrypted-tbn2.gstatic.com/imag ... H4wk9jUzfb These bullets were SO effective, and made such nasty wounds, they were outlawed at the 1899 Hague Peace Conference as being inhumane. The British were in a dilemma; they wanted to adhere to the rules but they also wanted a bullet that didn't require shooting an enemy four or five times with to knock him down. The design they came up with and stayed with, through two world wars, is the MK. VII spitzer seen above. The first thing they changed was the round nose bullet; replacing it with a spitzer point. The reason for this is that, while the round nose tends to punch its way through bone and such, the spitzer point, when it hits bone, tends to get deflected easier. This makes the bullet begin tumbling in a wound and tearing up great amounts of tissue. This effect is enhanced in the Mk. VII bullet by making the forward section of the core from aluminum and the rear section from lead, as seen in the diagram above. As the mass of the bullet was disproportionate from nose to base, when the bullet struck bone the heavier base would try to pass the lighter nose and the bullet would tumble. The long round nosed Carcano 6.5mm bullet was the exact opposite of the Mk. VII, and that is why the Carcano never seemed to kill anyone. When, in 1938, the Carcano was reborn in the 7.35x51mm short rifle, a serious attempt was made to imitate the .303 Mk. VII bullet, as we all know that imitation is the sincerest form of flattery. The 7.35mm bullet had a spitzer point, like the MK. VII, and had the same aluminum nose/lead base core as the Mk. VII. Unfortunately for the Italians, production of the 7.35mm Carcanos ended in 1939, and the non-lethal 6.5mm cartridge was brought back. This is only one reason why the Carcanos received a bad reputation. I will explain a few more in the next post.

[RobertP]

The 6.5x52mm Model 91 Carcano long rifle was, as the model indicates, introduced in 1891. It was during a transition period in Europe that saw European armies abandoning the idea of a large calibre, low velocity black powder rifle in favor of a small calibre, high velocity rifle using smokeless powder. Many ideas were copied from rifle to rifle, such as the Mannlicher "en bloc" clip used in the Carcano and the Mauser type bolt that utilized two locking lugs. Suffice it to say that, with all of the sharing (and stealing) of ideas, the rifles that entered the First World War were all pretty much equal in design, and it would be difficult to claim that one was more accurate than the other. The 6.5mm Carcano M91 long rifle design did incorporate two features that were not seen in very many other rifles, if at all, and the jury is still out on whether these features made the M91 more or less accurate than other rifles. The first is the rifling grooves in the barrel. While maintaining the same 6.5 mm (.256") calibre (bore) as other 6.5mm rifles, the Carcano designers elected to make their rifling grooves deeper. This required a unique, wider bullet for the Carcano that measured .268" in diameter, as opposed to the standard bullet for other 6.5mm rifles that measured .264" in diameter. The deeper rifling grooves may have been the reason for the second unique design feature of the Carcano. Instead of the rifling grooves in the barrel being made at a standard rate of twist (ie. 1:8 or 1:9), the Carcano riflings were made with what is known as "progressive" or "gain" twist. The riflings began, at the breech (chamber) at a gentle rate of twist of 1:22.79 (one complete turn in every 22.79 inches of barrel length) and got progressively tighter towards the muzzle, ending with a rate of twist of 1:7.939. It was believed, and very well may be true, that this type of rifling enhanced accuracy and reduced barrel wear by giving the bullet a chance to build up its spin slowly and gently. Unfortunately, it was also complex and expensive to machine, compared to standard riflings, and led to critical supply shortages of Carcano rifles in WWI. Now, as the M91 barrel was almost 31 inches long, which aided in muzzle velocity and accuracy, it soon became apparent that not all soldiers needed such a long rifle for bayonet charges, and that some troops would be far better off with a much shorter carbine version of the M91, such as cavalry, mounted infantry, artillery, scouts and support troops. Fighting against the Austrians in steep mountainous country in WWI also proved the disadvantages of an extremely long rifle. In 1893, the first carbine was introduced, the M91 Cavalry carbine or Moschetto Modello 91 da Cavalleria. While many of these were manufactured as new rifles, a practice began in the 1890's of simply cutting the 31 inch barrel of a long rifle down to the 17 inch carbine length. The next carbine was the Model 1891 T.S. (Truppe Speciali or Special Troops), begun in 1898. These were all manufactured as new rifles, evidenced by their stocks. Many of the cavalry carbine stocks were plainly cut off long rifle stocks. These two carbines were the standard through WWI, and nothing much changed until 1924, with the introduction of the Model 91/24 carbine. This one model of carbine alone likely did far more to tarnish the reputation of Carcano rifles in general than any other factor. The 1920's were not the best of economic times for Italy and Italian arms makers, ever seeking corners to cut, expanded on the bad idea started with the Cavalry carbine. From 1924 to 1929, approximately 260,000 M1891 long rifles were converted into T.S. pattern carbines. As with the conversions in the 1890's, long rifle barrels were cut from 31 inches to 17 inches and the muzzles re-crowned. If this were done to rifles with standard riflings, performance, muzzle velocity and accuracy may have suffered somewhat but, in a rifle with progressive twist rifling, this practice was an absolute disaster. As I stated earlier, the riflings in a M91 long rifle begin, at the breech, at a gentle rate of twist of 1:22.79 (one complete turn in 22.79 inches of barrel length), and progressively get tighter until the rate of twist, at the muzzle, is 1:7.939. In other words, the designers of the Carcano bullet believed a final rate of twist of at least 1:8 was needed to impart enough spin to the bullet in order to maintain gyroscopic stability on its way to the target. By removing 14 inches of the tightest riflings from a 31 inch barrel, the bullets simply were not spinning fast enough. These carbines couldn't hit a barn from the inside, and there is still debate about whether or not the term "Humanitarian Rifle" applied to these carbines as well or just to the bullets. Speaking of bullets, Italian military issue rifle cartridges for the Carcanos had some serious problems, too, and their contribution to the reputation for inaccuracy is next.

[RobertP]

Italian military ammo for the 6.5mm Carcano was mainly manufactured by the company Societa Matallurgica Italiana, and the letters "SMI" can be seen on the headstamps of vintage Carcano ammo. For decades now, gun experts have warned against using military surplus SMI Carcano ammo as it has a reputation for being very unreliable. This unreliability shows up in several forms: 1. Hangfires - a situation where the shooter pulls the trigger and the firing of the rifle is delayed for up to several seconds. 2. Misfires - a situation where the shooter pulls the trigger and nothing at all happens. Rangemasters just LOVE these. 3. Short shots - a situation where the shooter pulls the trigger, the rifle fires but the bullet lands far short of its target due to a severe drop in muzzle velocity. The main cause of the problems with the SMI cartridges was in the primers used in these cartridges. For those not in the know, the primer is the little detonator seated in the base of a rifle cartridge. The bolt's firing pin strikes it, setting it off and the primer then ignites the gunpowder inside the cartridge. A composition of chlorate and mercury fulminate was used in the manufacture of these primers, and this compound proved to be highly corrosive. This problem was made worse by the "triangular" neck crimp used to seat bullets into the cartridge casings. Unlike the full crimp into a cannelure, often seen on military ammo, this triangular crimp did not provide a very good seal, and poorly stored SMI ammo often had deteriorated gunpowder. Further compounding the Italian's problem with SMI ammo was the fact that most of their 6.5mm ammo was made in the 1920's to satisfy the needs of their African campaigns. However, Italy had no intention of using the 6.5mm calibre round in WWII, and introduced the 7.35x51mm cartridge for the all new M38 short rifle design in 1938, with the intention of completely abandoning the 6.5mm round. The reasons for this change are another story altogether but, suffice it to say the 7.35mm bullet had "secret" features (slavishly copied from the .303 British Mk. VII bullet) that would once and for all put to rest the moniker of "Humanitarian Rifle". Adolf Hitler changed all this by jumping the gun and going to war years before the date he had promised Mussolini. Italy wavered reluctantly for months but finally, in June 1940, gave in to Hitler and declared war on the Allies. This left Italy unprepared for war and, partly due to ammo supply problems, the 7.35mm rifle program was halted in 1939, and the 6.5mm round was re-introduced, as there were still large inventories of 6.5mm cartridges. The problem was, though, that a great deal of this ammo was almost 20 years old by this time. In well manufactured ammo, this might not have been a real problem but, given the primer and crimp problems of the SMI cartridges, long storage only made the problems worse. Next: How the reputation got worse after World War Two

[RobertP]

It would seem that, following the cessation of hostilities at the end of WWII, there would be no way the reputation of the 6.5mm Carcano rifles as being inaccurate could get any worse but, this was not to be the case. Many Carcanos were brought home by Allied soldiers and these included, of course, the sawed off M91/24 TS carbines with the best part of their progressive twist rifling missing. A lot of the SMI 6.5mm ammo of the corrosive primer and poor crimp fame found its way back with Allied soldiers as well. To make matters worse, thousands of Carcanos began finding their way into North American and European sporting rifle markets. Not only were more of the M91/24 TS carbines now in the hands of hunters, another phenomenon began to occur. Remember the original M91 long rifle with the 31 inch barrel? When surplus dealers began selling these on the open market, it was felt the long barrel looked out of place on a hunting rifle, and these long barrels were cut short in an attempt to sporterize the M91. Here is a picture of the most famous of these:https://encrypted-tbn1.gstatic.com/imag ... dWF28uxtex While debate has raged for years over whether LHO received a short rifle or a carbine, the photo in the ad is of neither, unless the forward end of the stock and barrel has been modified in the photo. This modification might have occurred when the ad was being prepared, and would have not been connected to the assassination. The rifle in the ad is what is known as a "Suprema"; an M91 cut down in length to make a sporting rifle out of it. The giveaway is the large rear sight. The only carbine close to it is the M91/24 TS seen below. Also being a cut down M91, it shares the large M91 rear sight.http://candrsenal.com/wp-content/upload ... 891-24.jpg Note the obvious difference in the forward end of the stock and barrel, and that the butt of the Suprema stock is longer. The shortening of so many M91 barrels for the surplus market put even more rifles in the hands of hunters that were woefully inadequate of being able to give enough spin to their bullets to make them accurate. Add to this the imported SMI bullets with their bad primers and seals, and we can see the Carcano reputation deteriorating rapidly. Just when it seemed things couldn't get any worse, several other things began to take place. Onto the surplus market came four million rounds of 6.5mm Carcano cartridges manufactured by the Western Cartridge Co. of USA that were made in 1954, 1949 or pre-1944, depending on which particular fairy tale you happen to subscribe to. While the cartridges themselves were well made, there was a slight problem with the size of the bullets. Remember, several posts back, I told you that the standard diameter for all 6.5mm calibre rifle bullets was a bullet .264" in diameter, with the exception being the 6.5mm Carcano, which required a bullet .268" in diameter? Well, guess what diameter the Western Cartridge Co. bullets were? Yup, they have been measured with micrometers, and the diameter turns out to be .264", .004" too small for the Carcano. This difference in diameter is enough to drastically effect the accuracy of a Carcano rifle. Next: Hunting ammo for the Carcano, or 60 years of the wrong bullets.

[RobertP]

While there were adequate supplies of imported surplus SMI 6.5mm Carcano ammo and 6.5mm Carcano WCC ammo available to shooters, these bullets were all full metal jacket bullets and unsuitable (plus illegal) for hunting. Some hunters solved this problem by carefully filing off the tip of the copper alloy jacket, exposing the lead core and making it a soft tipped bullet, but this method was a crude way of making a soft tipped bullet. Some gunsmiths, such as John Masen of Dallas, Texas, would pull the Carcano FMJ bullets for customers and re-seat hunting bullets into the cartridges. As the only hunting bullets available for this would be the .264" diameter variety, once again accuracy was lost. It soon became apparent there was a market for 6.5mm Carcano soft-tipped hunting cartridges, and several ammo makers began making cartridges for the Carcano. Every single one of them used bullets that were .264" in diameter instead of the required .268" diameter and, in fact, a company by the name of Prvi Partizan used a bullet only .2635" in diameter. Either the manufacturers didn't know or they didn't care that they were a great part of the reason Carcanos were not shooting accurately. Needless to say, this put the finishing touches on the inaccurate Carcano rifle reputation. Lastly, the abnormally long and heavy (for the calibre) Carcano bullet was not exactly what would be called a "flat shooting" cartridge, especially not at the lower velocities the bullets travelled at. Cartridge makers such as Prvi Partizan began loading a shorter, lighter bullet (139 grains instead of the old 162 grains) into Carcano cartridges, and changed the nose to a spitzer point instead of the standard round nose. Likely, another reason was economics, as these shorter bullets were probably made originally for a more common 6.5mm calibre rifle. See photo below, comparing a standard FMJ 6.5mm Carcano cartridge loaded with a 162 grain bullet to the Prvi Partizan 6.5mm Carcano cartridge loaded with a soft tipped spitzer point 139 grain bullet:While there were adequate supplies of imported surplus SMI 6.5mm Carcano ammo and 6.5mm Carcano WCC ammo available to shooters, these bullets were all full metal jacket bullets and unsuitable (plus illegal) for hunting. Some hunters solved this problem by carefully filing off the tip of the copper alloy jacket, exposing the lead core and making it a soft tipped bullet, but this method was a crude way of making a soft tipped bullet. Some gunsmiths, such as John Masen of Dallas, Texas, would pull the Carcano FMJ bullets for customers and re-seat hunting bullets into the cartridges. As the only hunting bullets available for this would be the .264" diameter variety, once again accuracy was lost. It soon became apparent there was a market for 6.5mm Carcano soft-tipped hunting cartridges, and several ammo makers began making cartridges for the Carcano. Every single one of them used bullets that were .264" in diameter instead of the required .268" diameter and, in fact, a company by the name of Prvi Partizan used a bullet only .2635" in diameter. Either the manufacturers didn't know or they didn't care that they were a great part of the reason Carcanos were not shooting accurately. Needless to say, this put the finishing touches on the inaccurate Carcano rifle reputation. Lastly, the abnormally long and heavy (for the calibre) Carcano bullet was not exactly what would be called a "flat shooting" cartridge, especially not at the lower velocities the bullets travelled at. Cartridge makers such as Prvi Partizan began loading a shorter, lighter bullet (139 grains instead of the old 162 grains) into Carcano cartridges, and changed the nose to a spitzer point instead of the standard round nose. Likely, another reason was economics, as these shorter bullets were probably made originally for a more common 6.5mm calibre rifle. See photo below, comparing a standard FMJ 6.5mm Carcano cartridge loaded with a 162 grain bullet to the Prvi Partizan 6.5mm Carcano cartridge loaded with a soft tipped spitzer point 139 grain bullet:https://encrypted-tbn0.gstatic.com/imag ... TvLm7YFioV The difference in overall cartridge length is quite obvious. This had the effect of lengthening the distance from the bullet to where the barrel riflings began (freebore) far more than the Carcano designers originally intended. It was not until 2004 that a cartridge manufacturer by the name of Hornady recognized the problem and began making .268" diameter bullets specifically for Carcano rifles. Multitudes of "junk" Carcano rifles instantly began shooting more accurately. Edit: My apologies. The Prvi Partizan cartridge shown above is loaded with a FMJ bullet. It seems, according to the box, that the FMJ bullets were even shorter and lighter, weighing only 123 grains. Here is a photo of the 139 grain soft tipped bullet: The difference in overall cartridge length is quite obvious. This had the effect of lengthening the distance from the bullet to where the barrel riflings began (freebore) far more than the Carcano designers originally intended. It was not until 2004 that a cartridge manufacturer by the name of Hornady recognized the problem and began making .268" diameter bullets specifically for Carcano rifles. Multitudes of "junk" Carcano rifles instantly began shooting more accurately. Edit: My apologies. The Prvi Partizan cartridge shown above is loaded with a FMJ bullet. It seems, according to the box, that the FMJ bullets were even shorter and lighter, weighing only 123 grains. Here is a photo of the 139 grain soft tipped bullet:https://encrypted-tbn3.gstatic.com/imag ... 19XTxTyqYB

[RobertP]

That pretty much sums up the sad, and sometimes undeserved, tale of the "inaccurate" Carcano rifles. As we have seen, it was often modifications made to the original long rifle design that created the problems, especially in the case of the carbines. While the M91/38 short rifles (Oswald's alleged rifle) were assumedly made with new barrels with a 1:8.47 standard twist in these barrels, once again we have a short rifle that is still a shortened version of the original rifle. The M91 long rifle may have been accurate but, with its heavy bullet, it had a relatively mediocre muzzle velocity and was NOT a flat shooting rifle. By shooting the 6.5mm bullet through the 21 inch barrel of the M91/38, instead of the 31 inch barrel of the M91, the muzzle velocity drops by 2-300 fps, making the M91/38 short rifle even less of a flat shooting rifle than the long rifle. Couple this factor with the undersized .264" diameter Western Cartridge Co. bullets supposedly fired by Oswald, and I don't think Oswald could have made those shots.

[Dealey Joe]

OH WOW! that is most interesting, I had read somewhere about the variable twist and now I understand the actual meaning, very valuable information, thanks Robert, I will re read this a few times , being an old shooter it intrigues me to say the least.There is a picture of a cop carrying a Carcano out of the TSBD with a clip hanging out the bottom of the magazine, what is your thoughts on this if you are familiar with the picture? If not maybe I can find it and post it?

[RobertP]

Dealey Joe wrote:OH WOW! that is most interesting, I had read somewhere about the variable twist and now I understand the actual meaning, very valuable information, thanks Robert, I will re read this a few times , being an old shooter it intrigues me to say the least.There is a picture of a cop carrying a Carcano out of the TSBD with a clip hanging out the bottom of the magazine, what is your thoughts on this if you are familiar with the picture? If not maybe I can find it and post it?Hi JoeThis rifle, if we are thinking of the same rifle, was a Remington Model 8. I believe the photo is this one:https://encrypted-tbn1.gstatic.com/imag ... vNEqvYEThe Remington Model 8 was a semi-automatic rifle that was a favorite with Texas lawmen, especially Texas Rangers. Frank Hamer, who carried a custom made Model 8, with a "police only" 20 round magazine, in .35 calibre, was the Ranger who tracked and ambushed Bonnie and Clyde. At least three and possibly more Model 8's were involved in that ambush.This rifle could be confused with a Carcano, as the stock version had a similar protruding magazine.https://encrypted-tbn2.gstatic.com/imag ... gxMlwBelow is pictured Frank Hamer's Model 8 in the Texas Ranger Hall of Fame and Museum in Waco, Texas.http://thegreatmodel8.remingtonsociety. ... 41.jpgThis rifle had the strangest action of any semi-automatic, involving an inner and outer barrel visible at the muzzle of Mr. Hamer's rifle. Known, I believe, as "semi-blowback", when a round was fired, the inner (outer?) barrel would move backwards, pushing the chamber and action with it. The barrel would recoil forward first, stripping the empty cartridge and ejecting it, then the action would follow forward, picking up a fresh cartridge and chambering it, ready to be fired. (this explanation may be a bit incorrect and is done from memory of 35 years ago. If someone can explain it better, please do)P.S. Just found an excellent website on the Model 8 and the Model 81. As a shooting enthusiast, I figured you'd enjoy this, Joe. There is a video near the end showing these rifles in rapid fire. If you watch closely enough, you can actually see the muzzle of the inner barrel moving in and out.http://thegreatmodel8.remingtonsociety.com/?page_id=659

[ChristophMessner]

Thanks, Robert, for so much detailed information! It's good to know all the background sometimes, but it's also easy to to deal too much with the past while the presence is asking you for action.

[Dealey Joe]

Robert I would truly love to fire one of those, be a thrill I'm sure