M14 762

Calibres – The .308 vs .762

.308 and .762 are calibres of ammunition and rifles. On a Firearms Certificate you may be permitted to own a .308 rifle but you may notice that your ammunition is .308/.762 (so you could buy either) Why is this ?
Once upon a time there were only muzzle loading rifles.  The bullet and black powder were stuffed down the end of the rifle barrel.  This was time consuming, messy and involved carrying round a bag of the various bits.  The size of the bullet was determined by the size of the barrel but it was not a precise method.
So, someone decided that it was a good idea to put the components (bullet and powder) together and put it into a case that you could then insert into the rifle  via a slot called the breech.  Fast forward to the turn of the century and you get a round of ammunition called a “3030” round.  This number came from 30 grains of powder and .30 of an inch in size.  The American army adopted a .30-06 sizing but the case was so big that it made the rounds  heavy so they were difficult to carry around.
Then Winchester Rifles developed and produced a round whose diameter was exactly .308 of an inch.   This design is still popular today as our .308.  However NATO use metric measurements so they translated this to be a .762.   Generally speaking both .308 and .762 bullets fit in .308 rifles.  However a .762 rifle will not always accept .308 ammunition due a a small difference in the construction of the .762.
When it comes to metric vs imperial sizes for ammunition and rifles you can have a .22,(5.6 metric)  a .223 (5.56 metric) , .243 (6 metric).
For pistol rounds you have 9mm, .45, .357  but they are on a different blog post.

Trivia:   In 1878 John Moses Browning (then 23 years old) designed the 1885 Winchester single shot rifle.  It is said that he designed his first rifle whilst working in his fathers gun shop aged only 13 years old.  In the UK today you have to be 14 years old to shoot rifles unless you apply for special permission – how times change !

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