.303B ammunition

correct me if im wrong here - arent the 303 basically a 7mm bullet ? im in need of a little edumacation here as ive not looked into it but i remember the nomenclature on some rimmed cartirges i once purchase two decades ago saying something like that ,,,,but memory is beginning to fail me on things from that long ago ,

which reminds me i need to make a list of what i once [but no longer ] owned just so i dont forget , ive already forgotten the nomenclature for my swiss rifles , i can remember my US collection well both rifles and handguns but id like to have a reference for the upcoming ears if i can so i can at least talk of them if the opportunity arises

gettin old aint for sissys

.311 is 7.92mm but is listed as 7.7mm

1 mm = approximately .040" so even a fraction of a millimeter can be quite a few thousands of an inch which is why 7mm bullets are .284" and 8mm bullets are .323" J bore German rifles are 7.9mm (.318") and .303 British (7.7mm) are .311"-.312".

Bullet Smith wrote:

Sapper740 wrote:

1 mm = approximately .040" so even a fraction of a millimeter can be quite a few thousands of an inch which is why 7mm bullets are .284" and 8mm bullets are .323" J bore German rifles are 7.9mm (.318") and .303 British (7.7mm) are .311"-.312".

This is the most accurate and detailed explanation.

Shamu wrote:

Just to confuse things even more Wacko

the metric designation for .303 British is 7.7 X 56 (R) its exactly the same round though just the nomenclature varies.

The very first time I saw .303 referred to as 7.7mm was on some South African surplus bought some twenty plus years ago. The ammo was heavily varnished and didn't shoot well at all; if you broke the varnish seal between bullet and case it improved considerably.

Mick

i stand corrected - "... Wacko

the metric designation for .303 British is 7.7 X 56 (R)..."

i think thats what i recall seeing on the package , its been a lot of years ago and i am getting old

ill look in my stash to see if i still have any and come back to add info if i do , otherwise ill bow out as im not the bullet guy here by any means

im goodwith the cast cowboy bullets in 45 and 38 but otherwise im not a reloader to speak of

...and to further confuse you...

The .30-06 Springfield is an American-designed cartridge, and most (but not all) cartridges originating in the United States use groove measurements (which are larger than land measurements) when measuring bullet diameter. So, even though the bore of the rifle (measured across the lands) is .30", the actual bullet diameter is .308" because the bullet must closely match the groove diameter (.308" in a .30-06) in order to form a good seal in the barrel.

To make things even more confusing, most cartridges designed in other countries use land measurements. Take the 7.62x39 mm cartridge used by the AK-47 as an example. At first glance, it would appear to use a bullet with the same diameter as the .30-06 Springfield, since they are both 7.62 mm cartridges.

However, the 7.62x39 mm cartridge (designed in the Soviet Union), measures bullet diameter using land measurements instead of groove measurements. Because of this, the groove measurement (and the actual diameter of the bullet) is .312" (7.92 mm) instead of .308" (7.62 mm), a difference of .004".

However, .004" is a significant difference when it comes to actually shooting a bullet. While it may seem obvious, the way to avoid problems with improperly sized bullets is to shoot the right ammunition in your guns. If you're hand loading, you should use a reputable reloading manual to ensure you're using the right-sized bullet when hand loading for a particular cartridge...