The Firing Line Forums - View Single Post

Captchee · July 5, 2013, 06:45 AM

For some reason I been having a hard time wrapping my mind around just what your asking about . But I think I got it now .
IE your thinking of having a smooth barrel with no rifling but for a small section up at the muzzle which would be rifled .

I don’t think that would be advisable as im thinking what could happen is it could act as a restriction unless there was a taper into the rifling , something like a forcing cone .
But even then at such a distance from the actual chamber , it might still act as a restriction and cause over pressure .
Now that being said , I can say it has been done in the past .
There is a type of progressive rifling that that was used in some military applications in muzzleloaders , that had a section of the barrel that wasn’t rifled . From the start of the rifling forwards , it was a true progressive as the rifling twist rate was sped up to the muzzle . Maybe someone else here can refresh my memory as the name for that type of rifling escapes me.

Also I can tell you that back in the 70’s there was a couple companies who had BIG problems with their barrels in that some how they ended up with batches of barrels that only had about ½ of the barrel actually rifled . I would have to go look but I think I have one of those barrels still kicking around my shop .
I can tell you they were considered unsafe . .

But alas times have changed so maybe its doable today . Its past my knowledge base though and I would suggest talking to a barrel maker about it . They would know and should have some sound advise as to if it can be done or not .

July 5, 2013, 06:45 AM	#18
Captchee Senior Member Join Date: April 2, 2013 Posts: 439	For some reason I been having a hard time wrapping my mind around just what your asking about . But I think I got it now . IE your thinking of having a smooth barrel with no rifling but for a small section up at the muzzle which would be rifled . I don’t think that would be advisable as im thinking what could happen is it could act as a restriction unless there was a taper into the rifling , something like a forcing cone . But even then at such a distance from the actual chamber , it might still act as a restriction and cause over pressure . Now that being said , I can say it has been done in the past . There is a type of progressive rifling that that was used in some military applications in muzzleloaders , that had a section of the barrel that wasn’t rifled . From the start of the rifling forwards , it was a true progressive as the rifling twist rate was sped up to the muzzle . Maybe someone else here can refresh my memory as the name for that type of rifling escapes me. Also I can tell you that back in the 70’s there was a couple companies who had BIG problems with their barrels in that some how they ended up with batches of barrels that only had about ½ of the barrel actually rifled . I would have to go look but I think I have one of those barrels still kicking around my shop . I can tell you they were considered unsafe . . But alas times have changed so maybe its doable today . Its past my knowledge base though and I would suggest talking to a barrel maker about it . They would know and should have some sound advise as to if it can be done or not .