Collets for Barrel Holding

[Ten Mile Knives]

I was just wondering the other day, why don't rifles use a tapered collet setup to mount barrels into actions? If this method is secure and concentric enough for the tooling used to make the barrel on a lathe, then why no use something like an ER 25 collet geometry to hold the barrel shank? I understand that a lot of barrels are mounted in "collets" with straight shoulders. I mean specifically a tapered chuck with slits for clamping and a tapered recess in the receiver with a tapered nut to lock everything.

 

[SC45-70]

I was just wondering the other day, why don't rifles use a tapered collet setup to mount barrels into actions? If this method is secure and concentric enough for the tooling used to make the barrel on a lathe, then why no use something like an ER 25 collet geometry to hold the barrel shank? I understand that a lot of barrels are mounted in "collets" with straight shoulders. I mean specifically a tapered chuck with slits for clamping and a tapered recess in the receiver with a tapered nut to lock everything.

Collets are used to rapidly and accurately replace the parts they hold. Most modern rifles are not designed to have the barrel removed and replaced on a regular basis. Simply screwing the barrel into the action is more than accurate enough and cost effective.

SC45-70

 

[lysanderxiii]

A gun barrel is threaded directly into the locking fixture (receiver, barrel extension, whatever), and is mechanically held axially in place by the threads.

A ER collet requires a holder and a cap that threads onto the holder. The item in the collet is held in place axially solely by friction.

Assuming the "collet holder" is going to become your receiver, you now have two more parts, and the barrel is only held in place by friction.

What is the advantage of this?

(The required concentricity of a barrel to receiver is actually easily achieved with threading, has been for the last 150 years, or more.)

 

[rbernie]

If this method is secure and concentric enough for the tooling used to make the barrel on a lathe

It's secure enough for the application, primarily rotational and low amplitude. I dunno how well that would translate to securing a gun barrel, in which the forces would be longitudinal and high-amplitude. I assume that if you made the collet long enough, you could find a way to make it work and last - but then what would be the advantage over a barrel nut system, a la the Savage 10/110 line?