Small arms caliber sizes - why 7.62mm

[Gary J]

A technical question concerning caliber sizes.

Why did the Soviets use the measure 7.62mm as a projectile size ?
Was there a technical or ballistic reason as to the adoption of such an unusual "middle of nowhere" measure. ?

Why not 7.5mm or 8mm ?

I've often wondered about this choice, as it later became the standard NATO round size.

G.

[UnknownSoldier]

Same could be asked about 5.56mm I think it is down to there being an Inch equivalent like .303, instead of just .300 or .305.

ATB,
Tom

[Ben Evans]

It was explained to me when I was in the military that the AK47 used the short 7.62mm round (which tummbles) where in NATO they used the standard long 7.62 mm round. The Russians at the time could use our ammunition in their weapons whereas at the time the SLR as we had then could not use the shorter Soviet round. This is also just one of the reasons why we went to the 5.56mm round but then the wall came down and the cold war and soviet threat went away.

[Ben Evans]

PS "G", where in the east of England do you live? I lived in Thetford for 9 years before moving to Downahm Market, but now live back in the Midlands

[UnknownSoldier]

Your right the 7.62mm Short does tumble but it is also lighter than the ordinary round, but it also covers a shorter distance, perfect for close quarter fighting, unlike the SLR, which had a greater, unnecessary range (unnecessary in the fact that in CQB your rarely further than 100 yards from your foe, so why be able to fire 700 +++ Also the lighter weight allows more rounds to be carried and so increases combat effectiveness).

Although why the exact size was chosen I have no idea. :-)

Tom

[Ben Evans]

With the SLR we zeroed our rifles to 300m, this was the preferable killing distance, one round hits and away enough for the irons sights of the AK not to be as acurrate. Also at the time and it still is the support weapon was the GPMG, which had an ideal beaten zone in the sustained fire role of 800m, even at this range the NATO 7.62mm was very effective, again keeping the enemy as far away as possible but sustaining max casultys in the process. Also one round for all the weapons, SLR rounds can be linked with the fired GPMG link for more ammo for the main section weapon, 75% of an 8 mans section fire power. like wise, GPMG link can be broken down and used in the SLR's. Tactics have now changed and we have support weapons of 7.62mmm GPMG's, 0.5 Cal heavy MG's, we have the 5.56mm minimi link or mag fed. Also the 7.62mm round could be used in the USM60 and the German MG3 and visa versa. Hope this all helps

[Adrian Stevenson]

Hi Guys, the use of 7.62mm as a calibre was due to several factors.

Firstly, it is a good size round with excellent balistic qualities: when it was adopted in 1891 it was not known as "7.62mm" but was known as a "three lines". This was an archahic Russian system of measurement. One line was equal to one tenth of an inch; so "three lines" made .30 calibre. When the Bolsheviks adopted the metric system it became 7.62mm

Hi Ben, in actual fact, what you were told was an "old wives tale". I have heard this from many ex squaddies. The Soviet 7.62mm round used in the AK47 measured 39mm long. The NATO 7.62mm round measured 51mm long. Clearly they were not inter-changeable. The original Russian 7.62mm round was a rimmed cartridge and measured 54 mm long.

Cheers, Ade.

[Ben Evans]

Hi Ade, I know our round was much longer, in Iraq I have fired lots of 7.62 short weapons, and I did actuallu ask that question, it was replied that the neck of the chamber would take the extra length of the NATO cartridge. I am going re join and do another 23 years to check that out (not)

[Adrian Stevenson]

Hi Ben, Actually would you go back in if you could?

You were right to question the interchangability issue. There is no way they could fit.

Cheers, Ade.

[Ben Evans]

Ade, I miss the lads and the can do attitude but 23 years mate was long enough, I now have some me & wife time