A question about rifling ..

[zzr1100]

I was watching a documentary about artillery the other day .. A cannon called the driggs was mentioned (1897 breech loading 1lb shell) apparently the twist rate of the rifling increases towards the muzzle end .. Has this ever been tried in a rifle ? If so why didn't it work ? (I'm assuming it didn't work anyways !)

[Sim G]

Called progressive or gain twist rifling. I remember some malarky a few years ago when it was mated with monolith bullets in order to build the better mouse trap....

[saddler]

...or gain twist rifling

Supposed to be a way to get around the high chamber pressures that happen when a bullet hits the lands/grooves of the rifled barrel & has to be made to spin

[GazMorris]

I was watching a documentary about artillery the other day .. A cannon called the driggs was mentioned (1897 breech loading 1lb shell) apparently the twist rate of the rifling increases towards the muzzle end .. Has this ever been tried in a rifle ? If so why didn't it work ? (I'm assuming it didn't work anyways !)

One of the problems with gain twist / progressive rifling is that it chews up the bullet jackets because of the change in angle of the rifling with respect to the bullet.

Gaz

[ovenpaa]

From memory Bartlein were pushing these type of barrels 2-3 years ago however I never hear of them these days. On the subject of large artillery pieces I remember reading about a large German gun that had the driving bands built in progressive larger sizes to allow for the barrel wear. The interesting part is there was something like 116 shots and then the barrel was scrapped off.

[dave_303]

If I recall don't some models of Carcano have it aswell?

[R.G.C]

From memory Bartlein were pushing these type of barrels 2-3 years ago however I never hear of them these days. On the subject of large artillery pieces I remember reading about a large German gun that had the driving bands built in progressive larger sizes to allow for the barrel wear. The interesting part is there was something like 116 shots and then the barrel was scrapped off.

David,
It was the 'Parizer Kanone" who bombed Paris in 1918 from some 60-70kms away. After that amount, the tube had to be returned to Krupp to be rebored.

At the end of WW2, the germans testes a gun who, not only had a progressive twist, but also a taper bore. From memory, it started at 27mm and ended at some 20mm...

With modern cut rifling CNC driven machines, progressive twist are just a programming affair.

As Gaz mentions, bullet jacket deformation is certainly to consider in terms of accuracy.

Despite Dallas, The Carcano was not a model of accuracy.
R.G.C

[Sandgroper]

I suppose it depends on how you define accuracy? I'm happy with the accuracy of my Carcano M91/28TS and IMO it's no worse/better than any other battle rifle of period. On the other hand the quality of Italian ammunition during WW2 left a lot to be desired.

The Carcano served the Italians well in two world wars and was only retired by the Polizia di Stato (State Police) in 1981! I understand that one of the reasons for the Italians choosing gain twist was that it prolonged the barrel life. I assume they saw this as an advantage over the higher production costs.
My Carcano has gain twist rifling which I believe starts at 1in18 and finishes at 1in8.

[R.G.C]

I suppose it depends on how you define accuracy? I'm happy with the accuracy of my Carcano M91/28TS and IMO it's no worse/better than any other battle rifle of period. On the other hand the quality of Italian ammunition during WW2 left a lot to be desired.

The Carcano served the Italians well in two world wars and was only retired by the Polizia di Stato (State Police) in 1981! I understand that one of the reasons for the Italians choosing gain twist was that it prolonged the barrel life. I assume they saw this as an advantage over the higher production costs.
My Carcano has gain twist rifling which I believe starts at 1in18 and finishes at 1in8.

Senggroper,
I would not argue on the Carcano qualities, my only experience being with a captured one in Lybia who found its way to central Africa with a bunch of ammunition....Very poor shooting Ammo or rifle, Ido not know

Regarding the use of old rifles by police forces, the french Garde Mobiles' kept the Mousqueton 16 for riot control very long as well, although there was no longer ammo for it, but its shortness was very handy for the task.

R.G.C

[Sandgroper]

R.G.C.
Mousqueton 16 - I had to look that up! I'm glad I did, it's a very nice looking carbine.