Sizing Question

[Three-Fifty-Seven]

I bought a left over extra 5 cavity mold for my AK 47's from Swede here http://castboolits.gunloads.com/showthread.php?t=65839&highlight=7.62
http://i153.photobucket.com/albums/s220/ShawnTVT/Guns/NOE314SP129.jpg

My question is . . . I just finally slugged the barrels on both guns, and they come out at .3085" I measured a few empty fired cases with my calipers and the measure .312" I also measured a loaded jacketed round, and it measures .3088"

I would like to size the least I have too, but don't want to fat of a boolit . . . could I size to .311 or is that too much to push down the barrel? I also don't want to loose too much of the lube groove.

I have only cast and loaded for handguns before, so this is all new to me . . .

As the saying goes "measure twice, cut once!"

[Piedmont]

Sizing to .311 will cause no harm to your barrel. That bullet has a deep lube groove so don't worry about losing lube, either.

I don't really have a good handle on what the inside neck measurement really means. I think it is the inside diameter of a fired case that you are specing at .312. So rhetorical questions are was that a full power load? How malleable is that particular brass? And you will always have some springback so what exactly does the .312 measurement actually mean?


The only thing you really have to be concerned with when loading large bullets is can they release from the case. A trick I use is to mark all of the cartridge neck of a loaded round with a black magic marker. If it isn't being marked upon chambering all the way around the circumference, it can freely release. So you chamber the loaded round, extract and examine.

[HeavyMetal]

Sizing the least is a very good place to start.

Surprised you have an AK with a 308 barrel.

If I was loading for these guns my first concern would be to size enough to get a good crimp on the gas check. and .311 sounds like the place to start.

I would load a few dummy rounds and adjust both seating depth, if you can but I think the mags will "adjust" that for you, and make sure they chamber and eject easily.

At that point I would start load devlopment. The 7.62x39, if that's your chambering, is about the same power level as the 30-30, 30 Herrett.

I will suggest H335, H322 and 2400 in that order.

If you haven't fired these guns yet you are in for a surprise! Mine will throw case's 40 feet straight ahead over the firing line.

Several of my shooting friends are of the opinion the brass groups better than the boolits!

If you haven't considered it build some type of brass catcher that suits the type of shooting you will do or you will never find your case's!

[Three-Fifty-Seven]

Yeah, I was surprised too . . . I slugged it three different times on the first one! (I used fishing sinker's) It is a Polish 1960 model with a milled receiver.

The .312 measurement is the inside of the neck measurement from a fired case, this is from full power yugo surplus brass cased ammo, throws the empties 25-30 feet kinda at the 2 O'clock area! I really want to cast and load my own . . . got some boxer brass waiting . . .

Yes it is 7.62X39 I'm loading it for, got the mold already paid for . . . got a checkmaker from PatMarlin paid for, now I just need a sizer for my RCBS LAM II . . .