The C No. 7 uses a standard No. 4 bolt with a modified bolt head. The British no. 7 uses a special bolt and bolt head and the barrel intrudes into the boltway by about 1/2 inch. The barrel on the Brit. No. 7 has a platform on the bottom half of the breach end which acts as a loading platform. The bolt head looks like only a half bolt head so it can fit over this platform.
The above mentioned parts are not interchangeable making the two rifles different.
The above mentioned parts are not interchangeable making the two rifles different.