I've had this fired No. 44 practice plug in a distorted adapter for many years; and I want to know what shell it's from! I always assumed a 6-pr, but an Australian friend has a 6-pr head, without an adapter, with 36mm threads. Unfortunately, my example has 39/40mm threads (impact damage!). Can anyone confirm what head my example fits, perhaps a 6-pr with a larger nose hole?
![DSC_0320.JPG DSC_0320.JPG](https://www.bocn.co.uk/data/attachments/172/172276-b96661adaa76cefc8559e756f26b1d95.jpg)
![DSC_0321.JPG DSC_0321.JPG](https://www.bocn.co.uk/data/attachments/172/172277-73a730fec3cdb887948c619835625f6c.jpg)
![DSC_0322.JPG DSC_0322.JPG](https://www.bocn.co.uk/data/attachments/172/172278-0c507c1a25f208ca20fe8b3b46da2bcb.jpg)
![DSC_0323.JPG DSC_0323.JPG](https://www.bocn.co.uk/data/attachments/172/172279-afd9e8ae6f2d89822a5622a6cf543c42.jpg)
![DSC_0324.JPG DSC_0324.JPG](https://www.bocn.co.uk/data/attachments/172/172280-ede4888bf9166d328ddc1851342b8f6d.jpg)
![DSC_0325.JPG DSC_0325.JPG](https://www.bocn.co.uk/data/attachments/172/172281-49b0d0339431303411656deaf1636d50.jpg)
![DSC_0320.JPG DSC_0320.JPG](https://www.bocn.co.uk/data/attachments/172/172276-b96661adaa76cefc8559e756f26b1d95.jpg)
![DSC_0321.JPG DSC_0321.JPG](https://www.bocn.co.uk/data/attachments/172/172277-73a730fec3cdb887948c619835625f6c.jpg)
![DSC_0322.JPG DSC_0322.JPG](https://www.bocn.co.uk/data/attachments/172/172278-0c507c1a25f208ca20fe8b3b46da2bcb.jpg)
![DSC_0323.JPG DSC_0323.JPG](https://www.bocn.co.uk/data/attachments/172/172279-afd9e8ae6f2d89822a5622a6cf543c42.jpg)
![DSC_0324.JPG DSC_0324.JPG](https://www.bocn.co.uk/data/attachments/172/172280-ede4888bf9166d328ddc1851342b8f6d.jpg)
![DSC_0325.JPG DSC_0325.JPG](https://www.bocn.co.uk/data/attachments/172/172281-49b0d0339431303411656deaf1636d50.jpg)