The British Lee-Enfield rifle has a rear locking bolt, but, though rear locking is weak in theory, this action did most satis factorily all that was asked of it in the severest test that any rifle has had to undergo, namely the World War.
Furthermore, it was claimed for this rifle that the ease with which the bolt can be manipulated enables a higher rate of aimed fire to be delivered from it than from any other hand operated, bolt action rifle. Due to this rapidity of fire the Germans, in the first encounters of the war, attributed to the British Army many more machine guns than in fact they possessed.
The Swiss Schmidt-Rubin is a rifle with a rear locking bolt. The Krag-Jorgensen rifles of Norway and Denmark are types of (c), having one lug in front and another in rear and at a right angle to it. The large majority of military rifles are, however, locked in front, some, e.g., U.S.A., having a third lug in rear. Some bolts are made in one piece throughout their length, others have a detachable bolt-head and are known as two-piece bolts. The merit of the two-piece bolt is that, should the bolt contract under the successive explosions of ordinary usage, a cheap and effective repair can be made by fitting a new bolt-head and so obviate condemning the whole bolt.
When a charger is used, it is placed in guides on top of the body, thus permitting all five rounds to be pushed into the magazine in one movement, the bolt being first brought to its rearmost posi tion. The charger is then removed, and, in action, thrown away. When a clip is used it is placed complete with its rounds in the magazine, at the bottom of which is a spring pushing the rounds upwards. When the last round has been taken from it, the clip falls out by its own weight through a hole in the bottom of the magazine. This hole is liable to permit of the entry of mud or dirt into the metal mechanism, however. The most common magazines in army use take the form of a vertical box underneath the bolt when in the forward position. A platform, mounted on a spring, keeps an upward pressure on the column of cartridges ensuring that the top round is always in position for the bolt to drive it forward into the chamber. The French Lebel rifle is now so fitted, but not until 1915 was it converted, prior to which the rounds were held in a tube underneath the barrel, and were pushed to the rear by a spring plunger.
The box magazine in a different form is employed in the Krag Jorgensen rifle of Norway and also in the Mannlicher-Schoenauer of Greece. In the Krag-Jorgensen the box is on the right and the rounds are pressed by a spring lever underneath the bolt and come round and up into position towards the left of the bolt face when it is withdrawn. In the Greek rifle the magazine plat form rotates round an axis and against a spring. The rounds are loaded from the top, the platform yielding to the pressure of the loader's hand. When the bolt is to the rear this platform is caused by the spring to rotate in the opposite direction so feeding the rounds.
All rifles except those of France and Denmark are provided with a safety catch or bolt. This, when applied, prevents the firing pin from going forward if the trigger be pulled. Also, in most, its application prevents the bolt from being turned.