Few questions about size of 7.62 projectiles

homslice

homslice

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I have never smelted before but I am looking to start.
2 of the calibers I am interested in are 7.62x39 and 7.62x54. The problem I am currently running into is just lack of information (or too much information)
My Lee reloading book states that 7.62x39 is .312 in diameter and the 7.62x54 is .310... however looking in other books and online I am finding these that these are stated as the same or both .312, .311 .310
So what size mould should I buy and what size sizing die should I buy?
Can I buy a .312 mould and put it through a .310 sizing die?

Any help is appreciated.
Thank you.
 
Everything I shoot Mosin is better with a .312 bullet, but having that said, I slug all my bores to be safe.

If you understand the pressure signs you can test load them all for best results.

For x39 just go with the .310 cast.
 
It's not all that critical at least to start with. If you're dealing with Lee equipment I'd suggest you start with their pointed 155gr mold for 7.62x39 and Lee sizers for .311 and .314. As long as you're not really pushing the high velocity window you shouldn't have to worry about pressure. If the load will chamber freely, .004 over the bore diameter won't raise pressures measurably.
Grouch
 
Slug your bores first, if you get lucky you can use the same diameter for both. If both bores were 0.312, I would size to 0.314, basically 2 thou over what they slug to.
 
Spawn-Inc said:
Slug your bores first, if you get lucky you can use the same diameter for both. If both bores were 0.312, I would size to 0.314, basically 2 thou over what they slug to.
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I agree with this but I would add that the x39 rifles were made post war with better machining and tolerances. Many/most of them are chrome bore as well.

I've loaded up to 160gr for X39 with good results but you will have to re-adjust your sights if you want to shoot factory or surplus rounds, where the Mosin or X54r you can make loads that match original ammo specs
 
It's pretty hard to get lead bullets up to factory velocities in either rifle without severe leading. If your shooting cast, plan on keeping velocities less than 1800 FPS. Although some folks have claimed to really hone their alloy and lube to get higher it's not easy and requires a commitment to casting detail.

I slugged all mine to verify the Lee molds would work before I bought them.
 
That does leave still one question though. Can I use a 0.314 cast and put it through a 0.312 sizing die?
I haven't bought anything yet, so far I have just been collecting wheel weights but I'd like to know what to buy instead guessing what to buy.
I'm not sure what slugging is but I will look it up on youtube. I'm sure I will find out there.
Thank you for the information.
 
I have a few "push through" dies... I don't shoot well enough to blame .001/.002+ cast diameter vs. slugged bore diameter to know the dif between me and rifle. Undersized are obvious on paper... When I really size(swage?) down stuff, I'll get a smear/tendril that goes past the pushing-punch because of a serious size difference. I'll shave it off to put back in pot before seating. Bullets I've cast for 7.62/54r or 39 at .312 pass through .309 for all the .300's without issue

I've pushed much oversized buckshot through sizers (slowly) for gallery shooting. It's much less a handle pull than f/l resize of brass. . Cast through a sizer isn't much.
 
Ihave just started loading. My friend casts lead boolits ( he likes to spell it this way ). So far I have paid tuition in the manner of 1 pound of powder and a bit over 200 bullets with limited results. Slug the bore first. And use the powders recomended in the manuals ( lyman I have ).

My mosin slugs at 13.5-14 thou. That means i need cast bullets at 0.315-0.316. Molds and dies are available. Look for 303 british stuff.

Hope this helps. Stilll learning myself.
 
Size and fit seems to be AT LEAST as important as the alloy, probably more so. Undersize bullets will cause leading regardless of the hardness of the alloy. Quite a few people are using .314" cast bullets in the 7.62x54.

Slower powders can reduce leading in the throat and leade area.
 
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MuthaFunk said:
It's pretty hard to get lead bullets up to factory velocities in either rifle without severe leading. If your shooting cast, plan on keeping velocities less than 1800 FPS. Although some folks have claimed to really hone their alloy and lube to get higher it's not easy and requires a commitment to casting detail.

I slugged all mine to verify the Lee molds would work before I bought them.
Click to expand...

Gas check and powder coat em.
 
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