My spanky new 300 AAC blackout won't stabilize the lee 230 gr mold/boolit

[solarguy]

Bought a new 300 AAC Blackout rifle. I intend to shoot subsonic 95% of the time, with a suppressor. It has a 16" 1:7 twist barrel.

Also bought a Lee 230 grain Blackout 2 cavity mold. For my alloy (wheelweight and a little tin) it produces boolits of 226 grains.

The recommended powder is AA1680, which is pretty much unobtanium right now. What I used instead is Aliant Bullseye pistol powder. Enough to drive the projectile at 960 fps, so says the chronograph. I saw about 30 fps variability from the high to the low. And they are definitely subsonic. Bullseye won't cycle the action, which doesn't matter for my application.

As cast, the boolits measure .312 in the groove area. The main body of the boolit is .297 to .298. I don't resize. The factory supersonic ammo is 2.125 overall length. My subsonic reloads are 2.155 OAL. They are lubed with a 45:45:10 alox, Johnson's paste wax, mineral spirits mix.

Now the problem: I could not consistently hit the 8.5 x 11" paper at 20 yards, and they were obviously keyholing.

Factory supersonic ammo runs and shoots fine and accurate, so the barrel's not goofy or defective.

YUCK!

I don't dare run them through the suppressor until I know they will stabilize.

On to the questions:

1. Will driving them a little faster, say 1080 fps do the trick?

2. Will AA 1680 magically stabilize them at 960 to 1000 fps?

3. Anybody got a magic source for 1680????

4. Anybody have a favorite mold to produce a boolit that will stabilize and be accurate at 1000 fps???

5. Am I doing something wrong here? It's not my first time at the reloading rodeo and I thought this was supposed to work with a 230 grain projectile. Humphh...


Thanks in advance,


troy

[jthwan22]

Bullseye is a very fast burning powder. If you look a powder burning chart Bullseye is one of the fastest and A1680 is in middle of the chart. Load data usually use slower burning powder as the bullets gets heavier. Bullseys is even faster that fastest recommended powder for light 300 BO load like H110 and Lill Gun.

I am guessing in your situation the burn is so fast the bullet is skipping down the barrel with no chance to start the spin. Using lead bullet instead of jacket bullet would make it worst. If you can recover the fire round I doubt you will see any rifling on it.

[NoAngel]

That Lee is one of the most poorly designed turds to ever be cut.
I suggest you cough up a little extra money and check out NOE. They have some much better designed bullets and their mold quality is hard to beat.

[Sgtonory]

Never used the Lee. But have used a 230 grain lead bullet from a group buy. Works fine. I would look at a NOE mold and ditch the lee. I have used BE and it worked just fine as a single shot. I am trying to use Alliant 300 MP for subs at the moment.

[wlc]

I've shot the Lee bullet out of a 16 inch 8 twist barrel. No stability issues, just accuracy issues. I got in on the ACE group buy for his 230 grain bullet. That one shoots well out of the same gun. I am shooting that bullet over 10.2 gr of 1680. You might try a different powder, RL7, IMR 4227, AA5744 all come to mind. Your 7 twist barrel should have no trouble stabilizing that bullet, your "problems" must be coming from somewhere else. Have you tried seating it out further?

[376Steyr]

Have you checked the twist rate in the barrel yourself? Stranger things than a wrong twist rate on a new gun have been known to happen.

[destrux]

I have no problems with keyholing with that lee bullet in my .300 Blackout AR-15. It's got a 1-7 twist though (it's a CMMG 8.1" barrel). It's accurate enough for my use, I can keep all rounds in a 6 inch circle at 100yds with a red dot sight.

I load them using AA1680 (14gr, not subsonic) and also IMR 4227 (11gr, subsonic). No problems cycling at all. I load all to 2.255" which is the MAX for an AR-15 magazine. You have to load this bullet that long because of where the driving bands are located. If you load it shorter the neck may not grip the driving bands of the bullet well enough to keep it from pushing further into the case during feeding and handling. If you can push the bullet into the case at all with your fingers that's BAD.

Oh, forgot to mention they wouldn't shoot accurately till I started powder coating them and sizing them to .309" after coating them. It seems to add bearing surface and help stability, or maybe prevents gas cutting of the base, I don't know. All I know is powder coating them helped accuracy and stopped all leading and it helped immensely with that neck tension problem I mentioned.

I second the suggestion to check your twist rate though. There have been several cases where the wrong twist rate made it into a gun in the past few years with manufacturers rushing things the way they are.

If not, try powder coating and see if that does it. It's very easy. I tumble them in batches of 100 in a cool whip container using a tablespoon of harbor freight white powder coat in a little bit of acetone, then spread them on some mesh screen so they aren't touching and bake for 25 minutes at 400 degrees, then size them in a lee sizer die using no lube.

[Smoke4320]

"You might try a different powder, RL7, IMR 4227, AA5744 all come to mind."

Second That ..

Plus I would see if someone here is willing to send you 20 or so bullets from a NOE Mold
I have issues with the Lee mold in a Blackout.. Same mold worked fine in my 308 ..
Purchased the Ace 230 and the NOE 247 (with HP 225) Both shot just fine in the Blackout .. Like the NOE better because I have FN Cup points and deep HP Pins.. I can tailor 1 mold to many shooting conditions and velocitys

[solarguy]

I'll check the twist rate.

Wish I could try a different powder. Any sources???

[wlc]

Try seating them out to 2.22-2.25 and see what happens. Just under max mag length.
Do determine your twist rate.


As far as powders.....good luck. At least you have more option in the lower 48 than I do. I can't order them in and have to rely on the LGS. I make my rounds about every two weeks and if I see one I need I snatch it up. We are getting back to some semblance of "normal" except for most popular powders and the ever elusive 22lr.

[solarguy]

I confirmed that my barrel is a true 7:1 twist rate, so that's good.

troy

[Moonie]

That boolit has a reputation for having very bad accuracy. Some have added a gas check to the boat tail and that has helped. Personally I'd get another mold, I have that mold but do not use it as the accuracy was horrible for me as well in 2 1-8" uppers, no stability issues, just performance issues.

[Tackleberry41]

I have been holding off on buying that Lee mold due to the issues I see others having. Wonder if lee will come out with an improved one that gets rid of the boat tail.

Friend is looking to do a 300 AAC build, will the usual unique load not work in the 300?

[nekshot]

anyone try trailboss to go slow, those cartridges are almost straight. I gotta put my 300 bo barrel back on and try TB.

[wlc]

I have been holding off on buying that Lee mold due to the issues I see others having. Wonder if lee will come out with an improved one that gets rid of the boat tail.

Friend is looking to do a 300 AAC build, will the usual unique load not work in the 300?

If you are using it in an AR Unique most likely won't cycle the action. If single shot or bolt gun then yes it will work. I don't know what load you would/could use as I haven't tried Unique in my AR 300blk upper.


anyone try trailboss to go slow, those cartridges are almost straight. I gotta put my 300 bo barrel back on and try TB.

Trail Boss is another that won't cycle the action of an AR. I bet it would be real quiet in a bolt or single shot though.

If ya'll are loading for something other than the AR then pay my post no attention at all. Lots of powders would work for the 300blk and be quieter than the typical powders associated with the AR and 300blk as long as it is not being shot in the AR action with the expectation of cycling the action. I've got a really quiet load using green dot with a 180 grain jacketed bullet but it won't even think about cycling or even unlocking the action of my AR.

[Artful]

The fast BE powder - the heel of the boolit sticking inside below the neck - not ideal.
First I'd chrono the factory loads and measure a factory bullet for length, as that you said is working.
And look for slower powder - 5744 and 680 work well but others using different powders.
good site to check on http://www.300blktalk.com/forum/viewforum.php?f=141
http://www.accuratepowder.com/wp-content/uploads/2010/09/WP_LoadSpec_7-2-13.pdf - page 37

I'd also look at another boolit design - NOE makes a good one, well actually several.
shorter is easier to stabalize but feeding can be an issue with the AR
Also slug your bore and throat, that will be a determining factor.
Boolit fit is very important to accuracy, and hang in there as I have never meet a rifle that shoots
j word that wouldn't shoot boolits with a little experimenting.

As you don't care about cycling - look at the LEE 155 grain Ed Harris boolit
http://www.midwayusa.com/product/752956/lee-2-cavity-bullet-mold-c312-155-2r-762x39mm-312-diameter-155-grain-2-ogive-radius-gas-check
or
tumble lube version
http://www.midwayusa.com/product/339539/lee-2-cavity-bullet-mold-ctl312-160-2r-762x39mm-312-diameter-160-grain-tumble-lube-2-ogive-radius-gas-check
and search for some other people's favorite loads in powders you have on hand.

My lightest / cheapest blackout load:

LC 5.56 case, 1.360 +/- .001"
CCI #400
165 grain cast
4.5 grains of Unique
1.965" oal

Averages 990 fps

Silly quiet out of my silenced bolt action, especially if the can is wet. Makes one ragged hole at 50 meters.
or think about the Lee 180gr for the Enfield or the Lyman 314299 at 200 grs

[Twstanley]

Try and find a powder with almost the same burn rate as 1680, I found and am using Norma 200 in my 300 blk for the heavy subsonics - I would load as long as an oal as you can, up to 2.25. And at least a light crimp so the round stays still chambering and to make pressure consistent.