Looking for 300 AAC bullet Design

[Shooting Supply]

I am looking for a 300 AAC bullet design that will fit in the Lee 6-cavity mold block (1 inch max length).

I was thinking something like their 7.62x39 bullet at .308 with a plain base, about 165-170 grains. But someone else suggested a lighter bullet in the 120 to 130 grain range.

So I am looking for some input as to what would be the most popular, and maybe a design to have made.

Thanks,

Mark @ Shooting Supply

[tja6435]

.308 is too small. Most people size cast 30 cal boolits to .311" for the Blackout

[ShooterAZ]

The Lee C312-155-2R is a popular boolit in the Blackout, but good luck in 6 cavity. As stated .308 diameter is not going to get any takers. .311 or .310 is what is being used.

[Shooting Supply]

I have the Lee C312-155 in 6-cavity, but it casts a little bit large for the 300. Lee states their molds will cast between stated diameter up to .003 over. So that mold could cast up to .315 according to Lee.

I was thinking maybe the .308 or .309 would cast at .310 to .311, and not need a lot if any sizing.

Since I intend on using the powder coat, I would like to design it with a plain base and get rid of the gas check.

I would also consider the tumble lube design instead of the regular lube grove. Again in an effort to make a bullet that you can cast fast and not have to size.

[yovinny]

Not sure what you want to DO with it, as in sub or supersonic ? target or hunting ?

I havent done the BO myself yet, but FWIW. My buddie tried all the 30's I cast, along with the big BT design from midway and claimed to find his best accuracy with my Lee .312 185gr GC slugs pushed pretty hard.

[Shooting Supply]

I am looking for a design that would be fast to cast, (6-cavity Lee, powder coat, and maybe not need sizing), cheap to cast (no gas check). (Heavy enough so it won't need a gas check?) mainly as a plinking/target bullet.

Something that would be popular, and then set up a group buy at about $45 a mold.

So I figured I would start here with some advice on what the design should be. It could be as simple as the Lee C312 made to a plain base .310 diameter.

I also have a Lyman 311041 copy (Both GC or PB) in the 6 cavity mold, but I have been told that a lot of the 300's won't feed that bullet shape.

[StratsMan]

I've used the Lee C312 in my 300 BO, but in an AR platform... To keep it cycling reliably, the pressure (and velocity) had to remain high enough that I wouldn't want to forgo the Gas Check. Might have to revisit that idea if I PC those boolits.... But the PC is so thin, I think you may still see exposed lead at the corner of the rifling...

I 'spose I could search other threads to see if anyone has recovered PC'd C312's to see if there's exposed lead...

[adanymous]

I use the NOE 311247 PB 4 cavity mold. 10gr of IMR 4198 @ 1035 and my AR runs like a top. Although I am using an adjustable gas block and lightened bolt carrier.

That heavy bullet sure makes a nasty sounding WOMP! when it hits the berm.

[sparky45]

Your reasoning is acceptable, however, if you DON'T PC the Lead bullet has NOTHING between the Lead and the rifling, GC'd or not. I have shot 158 grain Lead, 198 grain Lead and the NOE 247 grain bullets in my 300 BO and ONLY PC'd them, without any visible signs of Leading. I haven't really pushed the 158 grain Lead bullets that fast, approx. 1400-1500 fps (as described in load development), but still no Leading. I see no use for GC'd Lead bullets unless you're pushing over 2000 fps in which case slumping would be a major concern.
I do like PC'd Lead bullets.



I've used the Lee C312 in my 300 BO, but in an AR platform... To keep it cycling reliably, the pressure (and velocity) had to remain high enough that I wouldn't want to forgo the Gas Check. Might have to revisit that idea if I PC those boolits.... But the PC is so thin, I think you may still see exposed lead at the corner of the rifling...

I 'spose I could search other threads to see if anyone has recovered PC'd C312's to see if there's exposed lead...