Chambering
GunCraft's gunsmiths in Cape Town have years of experience with chambering. Our machines at GunCraft are specially fine tuned to cut the perfect chamber.
GunCraft complies with the Firearms Control Act, 2000 regarding barrel changes, caliber changes, custom builds and other alterations.
What is Chambering?
Chambering is when the desired cartridge profile gets machined with a special tool, called a reamer, that cuts the exact dimensions of the cartridge into the rear of the barrel.
In this operation the headspace (wiggle room for the cartridge once chambered) along with other important aspects gets determined.
Benefits of a GunCraft chamber
- A well cut chamber provides accuracy.
- Longer case life.
- Makes the cartridge reloading process easier.
How it's done
At GunCraft we recommend that you first do an action blueprint before chambering.
Setting up:
The gunsmiths at GunCraft set up the barrel in a lathe to ensure that the bore of the barrel, not the outside, runs true or concentric with the spindle rotation, using special tools and techniques.
We set up the barrel through the lathe spindle bore with a spider jig on both sides. Tight fitting range rods are inserted and clocked out. Once the bore runs perfectly true, the range rods are removed. Then the lans and grooves are precisely clocked out where the lead of the chamber is going to be.
At GunCraft we use Mitutoyo Finger clock gauges with a measuring resolution of 0.001mm (microns) to set up the barrel.
Cutting the chamber:
We predrill the chamber and machine the hole true. This makes for easeir and faster reaming, and lengthens reamer tool life. Then the chamber is reamed at slow machine spindle revs and by using the best available cutting oil.
Chambering is a long and meticulous process.
When the chamber is cut and headspace perfected by using sensitive gauges and feel, a chamfer is cut for feeding purposes.
When all is done the action is tightened onto the barrel and final headspace checks are done.
Barrel to action fit:
The chambering process includes fitting the barrel on to the action, where a thread is machined on the outside of the barrel, mating the two components. We take up as much space inside the action as possible, so between the bolt and chamber face there is no more than 0.2mm clearance. That means the case is as deep as it can be inside the chamber once it has been chambered.
The barrel is fitted before the chambering process is done and the same precise measuring techniques are used. After the barrel has been fitted, we measure again to ensure barrel bore runout is unchanged.
Other chambering needs
If you struggle with cases getting stuck in your chamber and there's no sign of over-pressure, it could be that your chamber has rusted. Get your chamber polished at GunCraft.
Example of chamber polishing by GunCraft
