.30Cal & 7.62

Boomer686

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Been reloading for a quite a while and it just goes to show you can always learn something new....

Always knew .303 need .311" bullets but I just noticed while snooping around on the Hornady site.. 7.62mm bullets are listed as having .310" diameter as opposed to .30cal with .308 ?? So what's with the "interchangability" (sh*t is that even a word :D) between 7.62Nato & .308win Is it just nomenclature? Somewhat misleading...

Regards,
 
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7.62mm bullets are listed as having .310" diameter as opposed to .30cal with .308 ?? So what's with the "interchangability" between 7.62Nato & .308win s,

Those bullets are intended for Russian 7.62mm calibers, 7.62x39mm and 7.62x54R. Their standards are slightly different than ours. 7.62x51mm uses standard .30 cal bullets.
 
Not all 7.62's are created equal, lol. Russian 7.62x39 bullets are usually .310 diameter. Russian 7.62x54 bullets are usually .311" diameter. NATO 7.62x51 bullets are usually .308" diameter.
 
Not all 7.62's are created equal, lol. Russian 7.62x39 bullets are usually .310 diameter. Russian 7.62x54 bullets are usually .311" diameter. NATO 7.62x51 bullets are usually .308" diameter.


Also quite available is .312" for x54 Russian. I get better accuracy with them, but it doesn't hurt to slug the barrel on milsurp rifles. The difference between .311 and .312 is about the thickness of a cigarette paper.
 
:popCorn:
I've been wondering this myself but never had the cajones to ask.....thanks Boomer

Never too late to learn a few more tidbits of info. I must have seen this 100's of times.. just never took the time to ponder it much.

I realize the differences in the combloc weapons.. just never rang true for me as my mindset was always thinking US manufacturer making products for the North American market.

The real danger is when you think you know it all and therefore stop asking questions :runaway:

Regards,
 
7.62 mm = 0.300" or 30 Cal. this is the measurement between the lands/raised portions in the bore on all 30 cal rifles be it civilian,NATO or combloc calibers. The difference between civilian,NATO and combloc 30 cal. rifle bores is the groove to groove dia. which can range from as small as .307.5" in some older lever guns to .315" in Mosin rifles. If your not sure of the groove dia. of your particular rifle especially and older surplus rifle it's best to slug the bore and use the appropriate size bullet.

http://7.62x54r.net/MosinID/MosinSlug.htm

The x 39,x 54r and x 51 nomenclature are all case lengths to the nearest milliliter.
 
I was reading in my Sierra reloading manual that they tested both .308 bullets and .311 bullets out of their .311 diamater rifle, and that they got pretty consistant groups with both sized bullets. I've yet to do any 7.62x39mm reloading, but I do plan to get into it, so I'm curious to know if anybody here has any experience with this.
 
Both my Norinco and Yugo SKS bores slug at .312" In my testing 308 dia. jacketed bullets didn't group well at all in either of my rifles. Jacketed .310 dia. bullets shoot the most accurately hands down followed by .311 dia.

Cast bullets shot as cast from the Lee 160 gr. tumble lube mold and gas checks applied using the Lee .314 push through sizer shoot just as well as the .310 bullets in both my rifles.

I wouldn't say not to try the .308 bullets in your particular rifle they may shoot just fine or they may not only testing will tell.

A couple old post from another forum I belong to.
http://www.sksboards.com/smf/index.php?topic=30961.0
http://www.sksboards.com/smf/index.php?topic=66214.0
 
I once loaded 220gn RN .308 Sierra bullets in my SKS. Can't remember right off but around 12gns unique got me just under 100fps. Accuracy was fine out to 100yds. Under 2in groups
 
7.62 mm = 0.300" or 30 Cal. this is the measurement between the lands/raised portions in the bore on all 30 cal rifles be it civilian,NATO or combloc calibers. The difference between civilian,NATO and combloc 30 cal. rifle bores is the groove to groove dia. which can range from as small as .307.5" in some older lever guns to .315" in Mosin rifles. If your not sure of the groove dia. of your particular rifle especially and older surplus rifle it's best to slug the bore and use the appropriate size bullet.

http://7.62x54r.net/MosinID/MosinSlug.htm

The x 39,x 54r and x 51 nomenclature are all case lengths to the nearest milliliter.



I think that is quite well said. Its actually very simple to slug the bore. My mosins and m44 have groove diameter of .3145 and .315. I wasn't overly pleased with the groupings of these rifles until I used a larger .312 bullet. The loading dies and brass don't care if you size up the bullet by 1 or 2 one thousandths of an inch, but the shooting can change from OK to really good.

Anything I load for, I slug the barrel first, especially milsurp rifles.
 
I think that is quite well said. Its actually very simple to slug the bore. My mosins and m44 have groove diameter of .3145 and .315. I wasn't overly pleased with the groupings of these rifles until I used a larger .312 bullet. The loading dies and brass don't care if you size up the bullet by 1 or 2 one thousandths of an inch, but the shooting can change from OK to really good.

Anything I load for, I slug the barrel first, especially milsurp rifles.

Mosins are goofy like that. I have an M44 that looks very well worn (and that I got for very little), but has a great bore that slugs out at .3085!
 
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