Casting for 300 blackout?

[Tazlaw]

Questions. I’m interested in casting for 300 blackout (110-150ish grains) for possible hunting whitetail and coyote. Does anyone know what mold would be good for a 30 cal boolit in that weight range? Please excuse my ignorance, I haven’t actually started casting yet but I’ve just about got all the stuff I need-Lee production pot, few molds, small amount of lead. I’m wanting a super-sonic load around 2000 FPS. Would that velocity need gas checked? And last question, would anyone care to share load data for such? Oh, really last question what should final size be (308, 309)?

Thank you all in advance.
Taz

[am44mag]

I can't answer on the mold, though I would suggest looking at some of what NOE and Arsenal has to offer. Find something with a large meplat (flat area on tip of the bullet), but that should still run smoothly in your rifle (I'm assuming you're using an AR-15).

At 2000 FPS, a gas check will more than likely be necessary unless you want to get into powdercoating your bullets. Since you're just starting out, I'd just stick with the gas checks. Sage Outdoors has some at really good prices, and he's an active member here. https://www.sagesoutdoors.com/gas-checks/

As for the final size, that depends on your rifle. Generally speaking, you want it about 0.001" over groove size. It's ok to go bigger, as long as it fits through the throat of your chamber.

[Lloyd Smale]

ive got 4 300 bos 3 ars and one ruger American. All of them shoot the rcbs 130 spitzer gas check bullet pc'd very well. Load I use gets a bit better then 2000 fps and my 16 inch gun and my American put it into less then 2 inches at a 100 yards. The ar pistols probably twice that but they have non magnified red dots on them. It shoots real well at 50 yards with pop gun loads using bullseye and unique in the American too. Makes for cheap subsonic stuff to shoot suppressed. I played with sub sonic heavies in the ars but there so dirty and fouled so quickly that I lost interest. If I want subsonic in the ars I use the same pop gun loads with the 130s using pistol powders and just run them manually.

[Ed_Shot]

Glad to see a 300 BO thread. I am learning and look forward to the discussion. Agree with Lloyd, the RCBS 7.62mm-130-SPC is a winner in 300 BO. I only load supersonic for my 16" AR and I also use the Lee 311-155-2R and NOE 311299. I use only commercial published data and pretty much stick with SIERRA's 300 BO data. I use the starting data for same weight j-word and work up. I use my own FreeChex III gc's on all BO boolits. I'm definately in the load-development phase. I've been concentrating on accuracy in the 1600-1900 fps range. In my limited experience I'm getting better results with Reloader-7 than with H110/W296 or 4227. My alloy is 3-2-95 and I get better results with "harder" water-dropped rather than air-cooled boolits. I'm personally not seeing a lot of difference between powder-coated boolits and those with 2 coats of White Label 45-45-10. Zero leading with either. IMO correct sizing diameter is what your weapon likes. My AR likes .309 and does not like .311. I have always sized with a Lyman 450 but found that no matter how careful I was mine bumped the boolit's nose too large for my AR so I got a Lee .309 push-through. I get perfect function in my AR (using PMAG mag's) with the RCBS 130 gr. loaded to a COAL of 2.00" and the Lee 155 gr. with a COAL of 2.050" and the NOE 200 gr. at COAL 2.180". Anyway, this is my experience thus far.

[John McCorkle]

Yup 300 BLK fills the freezer for me over and over again

Best success I've had is playing with alloys and velocity...which I didn't get into until a few years after I started casting. Not saying you can't start out that way...prob best you at least have a category for it in your mind as you progress.

I have alot of 300 BLK guns....2 bolt rem 700s, a number of ars ranging from 10.5 to 20 inch barrel (yes, 20 inch)

I hunt close which is key for a couple reasons...what range are you intending to hunt at? I love the caliber but it has its limits but within those limitations it works like a charm

You have 3 options all good. Depends on what firearm you are planning to shoot out of (bolt or semi) as some bullet profiles don't work well in semis that work great in bolt guns. You can 1) get a spitzer bullet and cast it of an alloy that will expand at the impact velocity you expect (I would gas check and powder coat...I've had fantastic success with the Lee 312_155 out of a 55/35 mix of ww (55 ish percent) pure (35 is percentage) and 10 percent tin (pewter) water quenched then powder coated with a gas check sized to 309 (most typical for most modern barrels, ymmv)

2) you can play with alloys and buy a hp mold...I haven't done this yet.....yet... Working on it though

3) you can get a mold with a wide flat nose (wfn) and work your alloy and velocity together to get great terminal performance too...some cast hard and disregard expansion all together but with 30 Cal that's not as easy as with say a 45 cal hole.

Accuracy is King. You can have a great bullet load combo bit if you miss it doesn't matter.

300 blackout is a fantastic deer round at distances around 100 yards and in ...it just plain works and I have a freezer full of meat to prove it.

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[popper]

I use the 31-142D GC & PC, alloy depends on how fast I push. I have pushed a PB 145gr to 2100 PCd, just over MOA @ 100. GC makes it easier. My target is hogs but not had a chance when I had the BO with me. 18" 1:10 carbine - choose the 145ish as it provides best energy/trajectory around 100 yds. Also fits the throat and neck best. 110 vmax is very short so seats long - not much neck tension and cast would need to be seated even shorter. 100gr half jacket plinkers are maybe 0.2" into the neck.
2K fps is on the upper end for anything over 135 or so, brass doesn't last long as P.P. get loose.
For long range (10" 1:8 pistol) I take the 110 vmax or 125 SST pushed hard. Playing with BO version of 150 speer.
Plan on a 309 push-thru Lee. My Lee size die expander is 307 and does fine, Lee might have a larger one you can 'fine-tune'.

[Conditor22]

I know you were asking about light boolits but -- the NOE 311-247-FN over 700X is subsonic, deadly accurate @ 100yrds (also hits like a tank, really rings the steel)

[blikseme300]

I use the 31-142D GC & PC, alloy depends on how fast I push. I have pushed a PB 145gr to 2100 PCd, just over MOA @ 100. GC makes it easier. My target is hogs but not had a chance when I had the BO with me. 18" 1:10 carbine - choose the 145ish as it provides best energy/trajectory around 100 yds. Also fits the throat and neck best. 110 vmax is very short so seats long - not much neck tension and cast would need to be seated even shorter. 100gr half jacket plinkers are maybe 0.2" into the neck.
2K fps is on the upper end for anything over 135 or so, brass doesn't last long as P.P. get loose.
For long range (10" 1:8 pistol) I take the 110 vmax or 125 SST pushed hard. Playing with BO version of 150 speer.
Plan on a 309 push-thru Lee. My Lee size die expander is 307 and does fine, Lee might have a larger one you can 'fine-tune'.

Interesting CB mold I was not aware of, going to fix that shortly. I'm guessing that the 31-142D should work in the 7.62x40WT and the 300HAM'R as well. My experience with the BO in AR-15's has been that a wall is hit with the limited case capacity and the fast twist rate when it comes to CB loads. The 7.62x40WT and the 300HAM'R open up other possibilities especially with the lazier twist rates, but that is another story. Going to get the mold and figure things out.

I modified a BO upper a few years ago to feed the Lyman 311041 and it worked well enough but the fast twist of 1:8 limited the velocity to around 1800 when accuracy fell apart.

[mattw]

I only have on 300 BO, it is an AR with 16" barrel and carbine length gas system. I have been shooting the NOE 311-152-SP-L1 in mine. The barrel on mine has very little leade and the rebated nose on this bullet is 100% reliable. I do not push mine real hard, 15.3gr. 4227 with this bullet gives me 1758fps for around 1072 ft/lbs of energy at the muzzle. It is very accurate and I would not question taking a 100 yard deer with it. This load could be laddered up quite a bit as it is not showing any pressure signs and in really cold weather (0 to +15), once in a while it will not hold open on last shot. This is not an issue in normal weather. I also have the NOE 314-129-SP, but without a rebated nose feeding is an issue, or should I say chambering is an issue. I can't seat it short enough not to roll a band of lead back and jamming up the works every 5 or 6 shots. The barrel is just not quite right for cast bullets.

[popper]

I specifically got 1:10 for the carbine. Both my barrels chambers are similar. Straight freebore to the bore except a slight/short 1 deg. taper right at the bore (right at SAAMI). Not enough to call it a ball seat but it will cause problems of jams if seated too long. Basically sized to fill the throat without jamming or seating short. You can get Tom to cut it to 307 and PC to bring up the dia. IIRC tried to make the 'D' match better than the 'C' version. D actually works well with BLL too. Gap on the GC shank collects any moved alloy. The 31-184C (?) works in the BO too - made for my Marlin 30/30. I run it slow in the pistol - both mine have wide feed ramps.

[Burnt Fingers]

I've got a .300 BO pistol upper on the way. 7.5" 1/8 twist. This will be my first .300 BO firearm. I've wanted a braced AR pistol for some time and did not want an obnoxious .223.

I'm looking forward to casting for this little blaster. I've been eyeing the NOE NTC310-135 in plain base. https://noebulletmolds.com/site/shop...y3-5-cavity-pb


Has anyone used that boolit in the .300 BO?

[2wheelDuke]

I put cast bullet 300blk hunting rounds on the back burner years ago. For paper punching, I was doing well with the Lee 155gr spire point (the one meant for 7.62x39.)

I tried using a softer alloy in that bullet for hog hunting thinking I could get some expansion. Well that didn't work. I wound up with a .30 caliber hole in and out and had alot of tracking to do before I could finally finish that sow.

I've got another mold now that was more true to CE Harris' intended design. It has a bit of a flat nose to it. But I haven't had a chance to test it much.

[DAFzipper]

I've used the NOE 135 PB. Can't remember exact numbers but I think it was at 1900 fps. CFE BLK. Still had a little room for more powder but it was shooting good.

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[DAFzipper]

That was powder coated

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[quilbilly]

Mihec makes a mold especially for the 300 BO that is absolutely outstanding! It is for 130 gr. boolits, two cavity, and is a convertible from semi-spire flat point to hollow point. Both my 30/30 and 32/20 love it. I have one cavity as hollow point and the other as flat spire (1/8" meplat) depending on which I am casting for. I don't have a 300 BO but if I did, it would be my go-to. It was a donated prize at NCBS a couple years ago which is how I acquired it in a plain brown wrapper so I had no idea what it was until I sat back down and found this gorgeous brass mold.

[Gamsek]

I used all of those MP mold bullets in my 300BLK bolt action, 312-440 and HG#38 don’t feed from magazine, but ALL shoot good. I killed roe bucks, foxes and one chamois with 312-159HP and 311-410 HP.

This is MP Molds newest 300BLK dedicated design in NLG and lube grove GC version. I like it a lot.

[Gamsek]

Mihec makes a mold especially for the 300 BO that is absolutely outstanding! It is for 130 gr. boolits, two cavity, and is a convertible from semi-spire flat point to hollow point. Both my 30/30 and 32/20 love it. I have one cavity as hollow point and the other as flat spire (1/8" meplat) depending on which I am casting for. I don't have a 300 BO but if I did, it would be my go-to. It was a donated prize at NCBS a couple years ago which is how I acquired it in a plain brown wrapper so I had no idea what it was until I sat back down and found this gorgeous brass mold.

Probably 311410 with long and short Hp pins. MP molds

[Burnt Fingers]

That's a real nice looking mold!

I might have to pick up one of those.

[Lloyd Smale]

yup me too. If it isn't at least 35 cal rilfe I use jacketed. In the bo I use the barnes 110. It shoots sub moa in my gun at a 100 yards and ive killed 5 deer with it out to 200 yards. Box cost about 30 bucks. that 50 deer for 30 bucks. Its well worth 2 bucks a pop to not have to track deer that run off or drag them out of the swamp.

I put cast bullet 300blk hunting rounds on the back burner years ago. For paper punching, I was doing well with the Lee 155gr spire point (the one meant for 7.62x39.)

I tried using a softer alloy in that bullet for hog hunting thinking I could get some expansion. Well that didn't work. I wound up with a .30 caliber hole in and out and had alot of tracking to do before I could finally finish that sow.

I've got another mold now that was more true to CE Harris' intended design. It has a bit of a flat nose to it. But I haven't had a chance to test it much.

[popper]

2wheel - shot a hog carcass with really soft 185gr GC in 30/30 from 5 or so ft. 30 hole in, ~40 hole out, gut shot. Same in shoulder and no exit. Don't think alloy makes much difference on them, harder will break bones AND exit. Broken bones only slows them down.
I don't recommend trying subs first - supers are quite easy as are results. Subs work but load and trajectory are tricky.
Got the 10" 1:8 pistol to work with cfe pistol and run down in the 12-1400 fps range (145-170gr) - no recoil to speak of and full function. Kinda H.D. blaster but 50yds isn't bad.