I recently got interested in Carcano rifles and picked a few up cheap. I got a M91, and M91/41, and an M91 that had been hacked up, but was reasonably nice. All are in 6.5x52.
I did some reading and found a few things that were pretty interesting. Most 6.5 Carcanos have a gain twist barrel, where the rifling starts out slow and gets quicker toward the muzzle. The 91/41 has a standard twist barrel, however. Being that the 91 and 91/41 look almost identical, this is kind of a tricky thing to find. I did a lot of work with rifling twist rates when I worked at Bushmaster and am pretty comfortable with external ballistics, as well as causes for understabilized and overstabilized projectiles. Bear with me a minute.
I think the reason that the Carcano has such a reputation for crappy accuracy is that if you cut down a regular twist barrel you only lose some velocity, whereas if you cut down a gain twist barrel you lose stability as well. This is what I am experiencing with the sporterized 91. The barrel has been cut to 20 inches, and is now not adequately stabilizing the 160 grain bullets.
By the way, most of the ammo currently available for the Carcanos is the wrong size. The 6.5 Carcano is made to take a bullet that is .268" in diameter, while the 6.5 Swede and every other 6.5 cartridge takes a .264" bullet. I am only aware of one commercial load with a .268" bullet and that is the Hornady loaded 160 grain RN JSP available from Graf's and Sportsman's Guide. The Norma and S&B 6.5 Carcano loadings are using .264" bullets. They shoot, but they are not accurate at all, and the Norma seems to have an issue with the case head. The Norma cases bind up in all my Carcanos, causing feeding and extraction problems even when they are unfired.
My unaltered M91 shoots like a house afire with the Hornady ammo, although it is shooting almost 18 inches high at 100 yards. This, believe it or not, is apparently the way the rifle is designed! The battle sight(short range fixed sight)is set for 300 meters! The first click on the rear sight is marked 600 meters. This rifle will soon be getting a taller front sight post to bring it a little closer to zero at the ranges I shoot, but it will put tiny little groups waaaayyyy up on the target as is. My best group with the military iron sights was 7/8 inches at 100 yards with the average being a little less than 1 1/2 inches for six rounds.
Did I mention that they hold six rounds instead of the usual five? I should have. That's another cool thing about these rifles, they use a little clip kind of like a Garand clip to hold the ammo. Just pull the bolt back and stuff it in the top, when you load the last round it falls out the bottom. These little clips last pretty much forever if you don't step on them. If you do step on them they get sort of smooshed and don't hold bullets or fit in the gun any more, so don't step on them.
The sporterized M91 was putting bullets through the target sideways at 50 yards, this means the rifling twist is no longer fast enough to stabilize the projectile. This rifle may shoot well with lighter bullets but it won't shoot the 160's worth spit. I'll be tinkering with this one some more. The 91/41 I didn't shoot because it is a project gun and it'll be going through some changes pretty quick. More on that when I get it finished. Recoil on both rifles was very pleasant compared to my Enfields and Mausers.
There is a fantastic website for Carcano information at http://personal.stevens.edu/~gliberat/carcano/
with tons of info and lots of links.
So, don't dismiss the Carcano just because of the reputation. I think if you give one a try you might be suprised. I know I was!
I did some reading and found a few things that were pretty interesting. Most 6.5 Carcanos have a gain twist barrel, where the rifling starts out slow and gets quicker toward the muzzle. The 91/41 has a standard twist barrel, however. Being that the 91 and 91/41 look almost identical, this is kind of a tricky thing to find. I did a lot of work with rifling twist rates when I worked at Bushmaster and am pretty comfortable with external ballistics, as well as causes for understabilized and overstabilized projectiles. Bear with me a minute.
I think the reason that the Carcano has such a reputation for crappy accuracy is that if you cut down a regular twist barrel you only lose some velocity, whereas if you cut down a gain twist barrel you lose stability as well. This is what I am experiencing with the sporterized 91. The barrel has been cut to 20 inches, and is now not adequately stabilizing the 160 grain bullets.
By the way, most of the ammo currently available for the Carcanos is the wrong size. The 6.5 Carcano is made to take a bullet that is .268" in diameter, while the 6.5 Swede and every other 6.5 cartridge takes a .264" bullet. I am only aware of one commercial load with a .268" bullet and that is the Hornady loaded 160 grain RN JSP available from Graf's and Sportsman's Guide. The Norma and S&B 6.5 Carcano loadings are using .264" bullets. They shoot, but they are not accurate at all, and the Norma seems to have an issue with the case head. The Norma cases bind up in all my Carcanos, causing feeding and extraction problems even when they are unfired.
My unaltered M91 shoots like a house afire with the Hornady ammo, although it is shooting almost 18 inches high at 100 yards. This, believe it or not, is apparently the way the rifle is designed! The battle sight(short range fixed sight)is set for 300 meters! The first click on the rear sight is marked 600 meters. This rifle will soon be getting a taller front sight post to bring it a little closer to zero at the ranges I shoot, but it will put tiny little groups waaaayyyy up on the target as is. My best group with the military iron sights was 7/8 inches at 100 yards with the average being a little less than 1 1/2 inches for six rounds.
Did I mention that they hold six rounds instead of the usual five? I should have. That's another cool thing about these rifles, they use a little clip kind of like a Garand clip to hold the ammo. Just pull the bolt back and stuff it in the top, when you load the last round it falls out the bottom. These little clips last pretty much forever if you don't step on them. If you do step on them they get sort of smooshed and don't hold bullets or fit in the gun any more, so don't step on them.
The sporterized M91 was putting bullets through the target sideways at 50 yards, this means the rifling twist is no longer fast enough to stabilize the projectile. This rifle may shoot well with lighter bullets but it won't shoot the 160's worth spit. I'll be tinkering with this one some more. The 91/41 I didn't shoot because it is a project gun and it'll be going through some changes pretty quick. More on that when I get it finished. Recoil on both rifles was very pleasant compared to my Enfields and Mausers.
There is a fantastic website for Carcano information at http://personal.stevens.edu/~gliberat/carcano/
with tons of info and lots of links.
So, don't dismiss the Carcano just because of the reputation. I think if you give one a try you might be suprised. I know I was!
