The Heym Express Magnum is a series of very powerful German rifles of the 1990s designed for hunting big game. They are available in 19 different calibers from the .300 Win Mag to the hugely powerful .500 Jeffery

.500 Jeffery

The .500 Jeffery is a caliber of rifles that first appeared around 1920, and was originally introduced by the August Schuler Company, a German firm, under the European designation "12,7x70 mm Schuler" or ".500 Schuler"...

 and .600 Nitro Express

.600 Nitro Express

The .600 Nitro Express is a round in the Nitro Express series which was introduced in 1903. It is the second largest calibre in the Nitro Express line, exceeded only by Holland & Holland's .700 Nitro Express round.-Overview:...

. Rather similar in appearance to the Mauser Gewehr 1898 (even if more massive and with an exposed barrel), they use a Mauser-type bolt akin to the one of the aforesaid rifle, even though the bolt is much more solid in order to handle better the huge recoil.
They are fitted with a 1-inch [25.4 mm] rubber recoil pad

Recoil pad

A recoil pad is a piece of rubber, foam, leather or other soft material usually attached to the buttstock of a rifle. Recoil pads may also be worn around the shoulder with straps, placing the soft material between the buttstock and shoulder of the person firing the rifle.The purpose of this device...

, and they have iron sights fitted on all types, but they can take a scope sight on the receiver

Receiver (firearms)

In firearms terminology, the receiver is the part of a firearm that houses the operating parts. The receiver usually contains the bolt carrier group, trigger group, and magazine port. In most handguns, the receiver, or frame, holds the magazine well or rotary magazine as well as the trigger mechanism...

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