Hey /k/ i am pretty new to guns and I have two quick questions.

>>31658106
The russian dude was drunk and labeled the 9 upside down.

Such is life.

>>31658106
>1. Why is the 7.62x39mm cartrdige called "7.62" when it's bullet diameter is actually 7.92mm

Russians measure caliber differently. Might be from between lands instead of grooves or something, can't remember.

>2. Why is weight of a bullet measured in "grains" rather than in grams like everything else?

Tradition, and because within the firearms industry it's already standardized the world over so it would be pointless to change it.

>>>/k/QTDDTOT

>>31658106
The smaller the unit you use, the more precise it is.

No one want to say give me the 7.62 3.004gramm bullets.

160 grain and its good to go.

Also 7.62 refers to the clipsize the vullet goes in

>>31658106
>Why is weight of a bullet measured in "grains" rather than in grams like everything else?
But they're measured in both.

>>31658106its 7.62 because it defines the barrel diameter, not the bullet. The billet is slightly larger to seal properly the barrel, thus increasinf propellant efficiency.

>>31658140
Well that explains a lot.

>>31658117
>Russians measure caliber differently. Might be from between lands instead of grooves or something, can't remember.
Everybody measures the caliber from the bore diameter of the rifle instead of the actual bullet diameter.

>>31658124
calm down kid

>>31658106
>Why is weight of a bullet measured in "grains" rather than in grams like everything else?
Because America uses the imperial system and likes to be special snowflakes

>>31658328
>America uses the imperial system
No we don't.

relevant to thread.

Some dude at the gun store told me steel cased and cored ammo, like the tulammo pictured in the OP will beat my gun up and wear my barrel out much quicker and that if I didn't want to destroy my gun, I should buy the much more expensive lead core and brass cased ammo?

He full of shit or not?

>>31658373
He's full of shit.

>>31658328
We don't measure bullets in ounces, senpai.

At one point in time, everyone used the Imperial system. Now it's just us and Thailand.

>>31658373
If he told you tula is steel core yes he is retarded.

Look up the lucky gunner test of steel case vs brass. It will wear your barrel faster than good brass stuff, but it's the cheap powder that does most of the damage and cheap brass case also uses cheap powder. And the money you save by shooting steel case outweighs having to replace your barrel faster. Most people will never come close to wearing a barrel out anyway.

>>31658363
You haven't switched to metric completely.
>>31658373
Yes, he's full of shit. The only thing it'll do is affect your accuracy slightly, be a tad harder to reload, and the only possibility is it won't cycle properly depending on your firearm

>>31658373
Tula is good to go. It's cheap and dirty, but it won't demolish your gun. No faster than regular brass ammo anyway.

Just watch out for steel-jacketed bullets.

>>31658386
>>31658399
>>31658404
>>31658407
Okay thank you.

>>31658110
Underrated posty

Most caliber designation make little sense and you shouldn't overthink them.

For example :
>7.92x57
>8mm Mauser
>8x57 IS
That's the same cartridge. Bullet diameter is actually 8.22 mm.

Different contries use different methods of designation and different measuring systems, henche the clusterfuck.

>>31658317
groove diameter or land diameter?
There is a difference, you know?

>>31658106
Other responses are missing the fact that firearms nomenclature is totally inconsistent in general. .357 and .38 are the same bullet diameter (.356"). So are .45LC, .454 Casull, and .460 S&W magnum (.452"). Sometimes it's metric, sometimes imperial. Sometimes it represents the bullet diameter, sometimes barrel inner diameter (measured several different ways), sometimes it reflects an earlier version of the cartridge that no longer exists, sometimes it's just convention so you can tell the difference between different cartridges with the same bullet diameter, and sometimes who knows.

Basically it's best to think of cartridge sizes as names rather than measurements. If you want to know actual dimensions, look it up.

Also, remember that rednecks are the main reason the US still doesn't use the metric system. What subset of the population do you suppose makes up the largest proportion of firearms owners and manufacturers?

>>31658373
>Steel core
It isn't fucking steel core, it is a bimetallic jacket - copper and steel - over lead.

Bullets are (usually) lead, with some sort of "gliding jacket" to reduce barrel leading (build up of lead). That gliding jacket can be copper (FMJ), bimetallic (steel and copper mix), a copper plating rather than jacket (Rainier bullets use this), and now there are bullets with polymer plating/coating.
Why not always use a full copper jacket? Copper is fucking expensive, and for it to work correctly, the copper and lead should be bonded. A bimetallic jacket reduces copper use, so it is cheaper. Copper plating is less copper, so also cheaper. Same with polymer.

This does increase barrel wear, but the cost saved in ammo will cover new barrels.

>>31658363
Yes you do.

>>31658511
Is re-barreling an AK a thing? I mean, it's not that big a deal on an AR but isn't the barrel hard pressed and riveted into the receiver on an AK?

You'd have to send it off?

>>31658460
Yeah, had an issue with this when I sent my weapon application to the local police station for a 1917 Mauser.
I listed it as 7.92x57 and they called me the day after, saying that they had NEVER heard of that type of ammunition for a mauser and it would of course be incompatible.

We argued back and forth until I went on wikipedia and looked up the other names for it.
The fucking moment I said 8mm mauser he went "ooooh, yeah I see it's listed as 7.92x57 now, we'll just write 8X57 IS instead"

I swear to god, some people are so fucking incompetent.

>>31658317

>Everybody measures the caliber from the bore diameter of the rifle instead of the actual bullet diameter.

Not true. For example .303 British has larger bullet diameter than .308 Winchester.

>>31658124
fuck off with your shit thread, that thread is half the reason we're smeared in tv/v/ etc etc bullshit all the time instead of gun threads getting the attention they deserve instead of burried in some garbage bin general

>>31658600
The barrel is pressed into the front trunnion, not riveted, and you can press it out at home with the right tools.

>>31658600
Yes you can re-barrel an AK, but it will take a legitimate workshop to do it properly.

>press out barrel pin
>press barrel out with funky U shaped stick stuck through the receiver end to press on the chamber area
>remove pins from all barrel components
>press those off the barrel
>press components (gas block, front sight base) onto new barrel
>press new barrel into gun (straight, not canted)
>drill and ream for a new barrel pin, install new barrel pin

The order of operations might vary slightly depending on what tools you have to do all that.

>>31658694
you also need to headspace it with gauges before drilling and reaming a new barrel pin hole

>>31658600
Certainly possible, but much more involved than replacing an AR barrel.

>(optionally?) cut rivets and remove trunnion from receiver
>press out old barrel pin
>press out barrel
>press in new barrel for correct headspace and clocking of gas port
>drill barrel for pin
>press in pin
>re-rivet trunnion to receiver if removed

Sounds easy, but it is even more easy to screw up the headspace and clocking, and many fit so damned tight that it makes minor adjustments difficult.

>>31658741
If you're only changing the barrel you have to press off and on all the barrel components too.

AK with barrel retention via a barrel nut would be pretty OP.

>>31658106
>2. Why is weight of a bullet measured in "grains" rather than in grams like everything else?
we Europoors sure do measure them in grams.
Most basic 7.62 bullets are 8 grams.