Author Topic: Tapered chambers.....is it a good idea? (Read 649 times)

hogship · « **on:** November 20, 2005, 04:03:16 PM »

There has been some discussion about tapered chambers. Some have said the originals were this way and maybe a few of the replicas were too.

But is this a good idea? There has been speculation as to whether tapered chambers make a better seal, thereby preventing chain fires. Well, OK, maybe and maybe not. The jury is still out on that one.

What I'm thinking about is the ball is instantly freefloating down that tapered chamber the moment it starts to move. A lot of blow-by, lack of support, and the possibility of the ball coming loose during handling.....And, I'm just not so sure it is a good idea for that ball to be bouncing down the chamber wall before entering the forcing cone.

I've also heard that blow-by in rifle barrels is one major cause of leading.

Well, I just can't understand how a straight walled chamber will not seal as well as a tapered one. In my mind, this just doesn't make any sense. After shaving lead at the mouth, I can't visualize the ball getting any smaller by pushing it a half inch further into the chamber.....and it seems like that would have to be the only way there would be a loss of seal between the bullet and chamber wall........make sense?

Certainly, I can see that out-of-round chambers will be problematic.....but this isn't what I'm attempting to discuss here.

hog

Rustyinfla · « **Reply #1 on:** November 20, 2005, 08:01:52 PM »

Hog,
It might be that obturation of the ball would cause the ball to fill out and make contact with the cylinder walls all the way down until the ball hit the forcing cone of the barrel.
I think another factor that a lot of people over look is the size of the chamber mouth in regards to the size of the forcing cone. there was quite a bit of talk on that over on sixguns.com a few years ago. It seems that there were quite a few .45 colts out there that had smaller chamber mouths than the diameter of the forcing cone so that the bullet never could fully engage the rifling. Fortunately this is rather easy to fix.

Rusty <><

Singing Bear · « **Reply #2 on:** November 21, 2005, 07:16:00 PM »

Hogship, try that flashlight test I talked about in the other thread.

The tapered chambers, someone told me about, was supposedly done by Colt to make the chamber last longer due to erosion. Straight walls eroded and left gaps. Tapering the chamber simply meant there was more "meat" and took longer for erosion to get to where the cylinder was useless. Since someone elsetold me this I can't substantiate how true this is, but it was told to me in response to my query about my first frontal chainfire problem and makes sense to me. :-)

Shorty · « **Reply #3 on:** November 22, 2005, 07:18:14 AM »

The taper on my '51 is so slight that I didn't detect it with dial calipers.
It's probably no more than 1 deg. on a side. I believe that it helps keep a ball tight regardless of the depth of seating.

Flint · « **Reply #4 on:** November 23, 2005, 06:51:26 PM »

Colt might have experimented with tapered chambers, but the references I've read usually are to chamfering the mouths of the chambers, to help ease the ball in. It must not have been a useful idea, as Colt reverted back to unchamfered chambers. Chamfering would help protect the edges of the chamber mouths from damage, much as crowning a barrel protects the edge of the bore at the muzzle.

I had a Ruger Old Army which was burred at the chamber mouths and when a ball was seated, it would be loose, as the mouth cut the ball diameter to less than the chamber. There, a tapered chamber would help, or even the chamfer. As it was, a pass with a triangular scraper cleaned it up.