Most people think that you can only own shotguns where the shells are loaded by hand (popular in clay shooting, for example), but you can actually own and use semi-automatic shotguns, such as this Benelli M4.
The Ruger 10/22 is one of the most popular rifles for new shooters in the UK. It's a semi-automatic rifle that has been in production since 1964.
Remington says that their model Model 700 bolt-action rifle is the most popular sporting rifle ever made with over 5 million sold. It's popular with police forces all over the world.
The Beretta ARX 160 is a military assault rifle used by the Italian army. The version below is a semi-automatic chambered in .22 LR that you can use in the UK.
There's quite a few semi-automatic .22 LR versions of military rifles that you can buy in the UK, including this Heckler&Koch MP5...
...this Heckler and Koch HK416, a version of the AR15 rifle that is used by special forces around the world...
...and you can now even something very close to an AR-15 made by Smith and Wesson. It's called the M&P 15-22 and is based on the real AR15 which is itself the basis for the rifles used by a huge number of militaries around the world.
Here's the hugely powerful Steyr HS 50.Cal. If you've got £5,000 and access to a shooting range big enough, you can have one in the UK.
you can only use at limited number of specialist shooting ranges