Anti-Tank Rifle

[Wayne McGee]

The gunner in your photo is obviously a veteran of at least one previous firing, note the neck brace.
The AIM here, of course, is not the destruction of enemy combat vehicles, but the testing of the Medical Branch in the treatment of head and spinal injuries, the rapid response of the Administration Branch in processing his Medical Discharge, and the Pay Corps in setting up his Long Term Disability Pension.
At least the Boys ATk Rifle had a muzzle brake and a recoil buffer spring.

Cheers