Range Report - 1891 Carcano (1896)

[vintage hunter]

I'd considered doing something similar with Nosler Partitions, forming a concave in the base sorta like a Minie Bullet.


BTW, does anyane know how the gain twist in a Carcano barrel starts out and ends up? Don't know how reliable the info I have is but it lists it as starting out at a rate of 1:19.25 at the breech end and finishing up at 1:8.25 an the muzzle and the rifling makes the same transition regardless of barrel lenght.

Information

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[Patrick Chadwick]

BTW, does anyane know how the gain twist in a Carcano barrel starts out and ends up? Don't know how reliable the info I have is but it lists it as starting out at a rate of 1:19.25 at the breech end and finishing up at 1:8.25 an the muzzle and the rifling makes the same transition regardless of barrel lenght.

For the M91: Starts at 578 mm (22.75") with a pitchangle of 2.02 degrees. Tightens linearly (i.e. there is no sudden tightening) to 201 mm (7.9", 5.8 degrees) at the muzzle, over a barrel length of 781 mm.
For the Moschetto M91: Starts with 389 mm (15.3", 3.00 degrees) and tightens to 190 mm (7.5", 6.12 degrees), over a rifling length of only 375 mm.

As you can see, the twist progression is NOT the same for all models, and on the Moschetto it is a fairly ferocious tightening, which is why it is not unreasonable to be worried about the jackets on oversized bullets being twisted right off the core.


Patrick

[jmoore]

As you can see, the twist progression is NOT the same for all models

How about the '91 carbine and the '91 TS? Those are the "shorties" I have. The carbine has been no dramas, if not very accurate. The "new" crapola TS was obtained partly just for these experiments.

[Patrick Chadwick]

How about the '91 carbine ...?

The Moschetto M91 is the carbine version of the M91 long rifle. Originally intended for the cavalry, it was designated Moschetto M91 d.c. ("da cavalleria")
after the introduction of the Moschetto M91 TS ("Truppe Speciali")

...and the '91 TS?

This uses the same barrel as the Moschetto M91 d.c.

And before anyone asks...

The Moschetto M91/24. The "pocket rifle". This is probably the nearest thing to those jokey "tanker" rifles fudged up from old Lee Enfields that was ever produced by a regular arsenal. The first version simply had the M91 rifle barrel cut down to a rifling length of 377 mm. Which meant that the faster twist end had been cut off, and it was a ballistic flop.

For the second version, someone applied a bit of thought before starting up the saw, and these had an M91 rifle barrel shortened at the breach end, and then an insert/sleeve made to attach this to a new breach. So the twist has to be worked out backwards from the muzzle, giving a twist at the muzzle of 201 mm (as already given for the Fucile M91) and 360 mm (3.25 degrees) at the start of the rifling, a little sharper than the Moschetto M91.

After all this, the Italian arsenal engineers must have been heartily sick of the whole gain twist business, and it is not surprising that the 7.35mm carbines and the Fucile M91/41 were designed with normal constant twist barrels.


Patrick

P.S. If there are any mistakes in the above values, it is probably because I am getting confused as well!

[jmoore]

Yah, stupid of me!

Moschetto

Somehow in my haste I had in my pea brain yet another even shorter variant, but all of the carbines are Moschetto models. (What's the plural of Moschetto?) My only "book" dedicated to Carcanos is a first (only?) edition Hobbs, and it's little more than high school term paper with drawings and one low resolution photocopy photo stuck in loosely. Still useful and was never intended to be an "end all, be all" reference!

[Patrick Chadwick]

What's the plural of Moschetto?

Moschetti