Metric vs. Standard Rifle Calibers: similarities, differences?


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BudS
June 7, 2003, 11:20 PM
What I see in print & talking with folks who THINK they know what is what, has been confusing as of late- so, I'm putting my faith in who I HOPE to be truely informed folks.

In both cases above, I have been told a 7.62 bullet is .30 AND .308 caliber. Not much difference, BUT enough to make a difference, so WHICH is it?

Also, my wife just bought me a nice Mosin-Nagant for Father's Day, which shoots 7.62 X 54R ammo...is there a commercially-made (NOT surplus) maker of this ammo like Winchester, Federal, etc.? I stopped at several stores today & didn't see any, but I DID get some at the gun show today (Czech stuff, brass-cased).

Now...what is the 7.62 X 54R comparable to, if at all? How does it stack up to .308, which I've been told & read is the same as 7.62 X 51 (is it?) :confused: I'm beginning to wonder if some of these folks actually know what they're talking about! :scrutiny:

Thanks a bunch for the lesson(s)!

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Quintin Likely
June 7, 2003, 11:50 PM
In both cases above, I have been told a 7.62 bullet is .30 AND .308 caliber. Not much difference, BUT enough to make a difference, so WHICH is it?

To the best of my knowledge, .308 Win, .30-06, and .300 Winmag(?) all .30 caliber rounds, use the same bullet diameter if you're reloading (anyone verify or correct me if I'm wrong please). If that's the case, then I don't reckon there's too much of a difference between the bullets themselves; naturally, case sizes are different though.

Also, my wife just bought me a nice Mosin-Nagant for Father's Day, which shoots 7.62 X 54R ammo...is there a commercially-made (NOT surplus) maker of this ammo like Winchester, Federal, etc.? I stopped at several stores today & didn't see any, but I DID get some at the gun show today (Czech stuff, brass-cased)

Congrats...and I believe Norma and Wolf offer factory loadings for 7.62x54R. Ballistics wise, the Rooski military load generates more muzzle energy than the US military's M118 load, and I think it shoots a bit flatter.

dakotasin
June 8, 2003, 12:41 AM
depending on who's doing the loading...the 7.62x54r falls in between a 308 and a 30-06, closer to the 308 than the 06.

FW
June 8, 2003, 12:48 AM
There isn't really a one-size-fits-all definition for a 7.62mm bullet. It depends on which one it is. Many firearm calibers are not designated by what they are exactly. For example, a .38 special and a .357 magnum fire the exact same diameter bullets. The .357 is the actually bore size in this example.

In general terms, a "7.62mm" bullet is a "30 caliber" bullet.

A .308 cartridge is sometimes called 7.62 x51 or 7.62 nato. The bullet diameter in this example is .308 inches.

A 30-06 cartridge also has a .308 inch diameter bullet.

A 30-30 cartridge also has a .308 inch diameter bullet.

In the case of most American "30 calibers" the bullets are .308.

When "7.62 mm" is used to describe Russian calibers, things are a little different. For example, 7.62 x 39 and 7.62 x 54 use bullets that are .310 inches in diameter.



In the above examples, there is .002 inches difference between the Russian and U.S. ammunition.

To make this more confusing, some guns made to shoot the Russian calibers above. For example a Ruger Mini 30 fires 7.62 x 39 cartridges ("Ak-47 ammo"), but has a bore for .308 bullets instead of .310. Some will say this can create excessive pressures, some will say it is just less than ideal for accuracy, but the fact is, almost all of the ammo available has bullets of .310 diameter. There are also cases where an American company may load cartridges originally designed for .310 bullets with .308 bullets. I believe the 7.62x39 soft points offered by Winchester are actually loaded with .308 bullets, but I may be wrong. If this is the case, firing them in most firearms in designed for 7.62x39 (AK's and SKS's, etc.) would still work, but might be less than ideal.

And it to make it more confusing yet, many Communist bloc rifles have bores of varying diameters. Some may be ideally matched with .308 bullets, .310 bullets, .311, etc. They only way to know for sure is to slug the barrel if one thinks it is worth the trouble.

Of course handloading overcomes all these issues.

There is commercially available 7.62 x54. I have heard Winchester offers some, but I have never seen it or seen it in their brochures. Norma makes brass cased, boxer primed 7.62x54, but it costs about $35 for a box of 20. Sellier and Bellot also makes 7.62x54 boxer primed brass cased soft points. It is reasonably priced (around $9 per box) and is reloadable. Wolf is considered commercial and is reasonably priced, but is steel cased like the surplus.

Concerning Surplus ammo, I've had very good luck with steel cased Czech "silver tip" ammo. It is found in light blue boxes with a a silver diagonal stripe on the side. The cases are greenish-gray in color and the tip of the bullet is painted silver. This silver tip doesn't designate it as being anything special like "armor piercing" or "sniper" ammo as some people trying to sell it might claim. I would recommend avoiding albanian made 7.62x54. It is probably the worst you can get. Some lots will work okay, and others will not. One of the main complaints about it is incosistent case dimensions. Some lots are very difficult to chamber is some rifles. It is easily identified by a brass case and it's head stamp. The two digits in the headstamp on one side of the rim indicate the year the other digit on the other side of the rim will be a "3".

One caution concerning surplus 7.62x54: Consider all of it corrosive and clean the rifle accordingly after shooting. Not too big of a deal, but it has to be cleaned after shooting and by a method appropriate for corrosive ammo. Some people selling surplus 7.62x54 will sometimes claim a certain type is "mildly corrosive. Don't treat this any differently than you would corrosive ammo. It is like the difference between being pregnant and mildly pregnant.

7.62x54 and 7.62x51 are NOT the same thing. 7.62x54 is a rimmed cartridge. 7.62x51 (aka as .308) is not.

7.62x54 may also be called 7.62x54R or 7.62 Russian (Sometimes 7.62x39 is also called 7.62 Russian)

7.62x54 IS the same thing as 7.62x53, a Finn designation you may encounter at some point.

Ballisticly, 7.62x54, 30-06, 8mm Mauser, .308 Winchester (7.62 Nato), and .303 British are all very similar. Of course this all depends on various loads, bullet weights, barrel lenght, etc. Handloading increases the possiblities.


I'm beginning to wonder if some of these folks actually know what they're talking about!

All I can say is, NEVER stop wondering. You will hear all kinds of BS concerning Surplus rifles and ammo.

I would suggest looking at www.mosin-nagant.net (http://)

You will find a lot of information there.

Deadman
June 8, 2003, 05:14 AM
I believe the 7.62x39 soft points offered by Winchester are actually loaded with .308 bullets


:confused:

Seeing as how I was shooting Winchester's 7.62x39 SuperX load the other day, can someone verify for me if they are indeed .308 in caliber or .311?

BigG
June 8, 2003, 08:05 AM
The Winchester White box 7.62X39 that I measured several years ago was .311 caliber.

David4516
June 8, 2003, 09:53 PM
30 cal, 7.62mm. and .308 all refer to the same diameter. Here is a list of some calibers I can think of that use this diameter bullet:

.30-30 Win
.30-40 Krag
.308 Win (aka 7.62 Nato)
.30 Carbine
.30-06 Springfeild
7.62X54
.300 Win Mag
7.62X25 Tokarev (this is a handgun round)

The 7.62X39 is an interesting caliber, because some rifles in this caliber are really .311 diameter, the same as .303 british.

Winchester does make 7.62X54 ammo, but it isn't easy to find. I've seen it online here:

http://www.outdoormarksman.com/merchant/merchant.mv?Screen=CTGY&Store_Code=om&Category_Code=CR-580-76254R

but they are out of stock more often than not...

At most stores, if you ask about a russian caliber, they are likely to look at you funny. The most common russian round is the 7.62X39, and even that one can be hard to find in most sporting goods places. I have this same problem trying to find ammo for my pistol. It's a 9mm Makarov (another russian round, it is also known as 9X18 ). When I go into your avaerage store and ask if they carry it, they often will hand me a box of 9mm Lugers. I guess the people who work in these places must think that all 9mms are created equal or something...

The 7.62X54 can push a 150 gr bullet at about 2650 FPS, the .308 win pushes the same bullet at about 2900 FPS, so .308 win has more "power". I think the closest "american" caliber in terms of power and case type is the .30-40 Krag, but the Krag round is a bit weaker than the 7.62X54...

BudS
June 8, 2003, 11:54 PM
Man, .308, .310, .311...I never knew all this! The Mosin-Nagant my wife bought me looks pretty good, barrel-wise. I haven't shot it yet. At the gun show this weekend, I saw 147-grain and 180-grain ammo. I think the 147-grain was silver-tip and I'm kicking myself for not getting some of it! Oh, well, there's another gun show locally in a couple of months....

So, what is good to shoot in the Mosin-Nagant? Either weight bullet? I know this 'un will kick- I've been warned to snug it up, both from the seller and from reading here! I want it to be an enjoyable shooter, not a chore.

Oh- is there a slip-on buttpad that'll fit it?

BTW, it's a Romanian M44, made in 1954....

Today wasn't wasted- I leaned something!:)

David4516
June 9, 2003, 03:15 AM
The Nagant isn't really a rifle, it's a flame thrower. Talk about muzzle-flash...

And don't forget to clean your gun when you use corrosive ammo...

Sleeping Dog
June 9, 2003, 08:39 AM
I think the Mosin shoots bullets that are around .311-.312. Bullets made for the Brit .303 should work.

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