? on 300blkout boolits in AR

[cs86]

Eventually I plan on doing a build for an AR chamered as 300 AAC blackout. I noticed that NOE has some molds specifically designed for the caliber. They are 247gr slugs, which to me even seems on the larger size for subsonic rounds. My questions is, will these stick to far out of the case preventing magazine fit? They are 1.335 long slugs with a seat depth of .46 to the crimp line. I could probably do the math, but I don't have a magazine here to know what the depth will allow.

I thought about buying a mold since they are available, but its pointless if it won't work in an AR mag. Correct me if I'm wrong but the 300blackout is used with a 223/5.56 lower correct?

[blikseme300]

The only differnce between the AR-15 in .223 and 300blk is the barrel. All other parts are the same. What are you trying to achive with this caliber? Do you have a can or are you just wanting to have an all-round rifle?

I have 3 16" AR-15's in this caliber without cans and the best combination for me is the Lee C312-155-2R sized to .310 lubed with member Randy Rat's Tac#1 with Hornady GC's on top of 17.7gn of Reloder 7. Disclaimer - Use this combination at own risk.

[Jailer]

That boolit will work but some have reported feeding issues with the flat meplet on the nose. Try the boolit exchange and see if someone will send you some to try in your gun before you buy it.

[nitrohuck]

I just cast up a ton of NOE 314-129 boolits and plan to test them out over 300MP powder, which is rapidly gaining a strong foothold in the 300BLK world.

To my knowledge, no one has posted any results with it in the 300BLK, but I have high hopes that this boolit will be a really great supersonic plinker out to 100yrds, and maybe even beyond.

Will be posting my results this week when I finally get out to test them

[Boolseye]

The Lee C312-160-2R also works great in 300BLK, loaded to 1.985" OAL.

[blikseme300]

The faster powders such as 300MP don't work with some AR-15 uppers as the gas produced is insufficient to cycle the action. The dwell time under the curve is smaller than Reloder 7 for example. I have experimented with a number of magnum pistol and small shotgun powders but the results were not up to expectations. CB and j-word loads are different in the AR-15 platform due to the particular needs of accuracy and action function.

As for larger meplat boolits not all feeding ramps are cut the same either. I modified one of my uppers to support the larger meplat boolits and these work very well on feral hogs. My favorite is the RD 165gn originally designed for the 30-30.

[Jailer]

My favorite is the RD 165gn originally designed for the 30-30.

I'm amazed that you can get that boolit to feed. My Savage bolt actions chokes hard on the HM2 Harris design and the meplet on that is only .155.

[Boolseye]

The Lee 309-170 feeds and shoots beautiful in my 300 BLK. That's basically a 30-30 boolit with a decent meplat.
I have a 16" carbine w/ an MAS 1/8 barrel, m4 feed ramps. I polished them when I assembled the gun, but did not open them up any more.

[cs86]

Thanks for the replies

[GabbyM]

If you haven not decided on what caliber you want. Check out the 25-223 or 6x45mm. That's the 5.56 x 45mm necked up to 6mm or 25 caliber. Unless you're wanting to run a subsonic round with a can 300 BO makes little sense.

[prsman23]

A 30 caliber round that functions very well sub or supersonic in a standard ar platform without modifications makes little sense???

[nitrohuck]

A 30 caliber round that functions very well sub or supersonic in a standard ar platform without modifications makes little sense???

+1


The 300blk is a reloader a dream, made from the most available brass on the planet, and topped off with one of the most common bullet calibers out there.

Since I already cast .30cal boolits, it was pretty easy to get started, plus I will be shooting 300blk for about $0.11/round, whereas most .223 out there is at least double that cost,

[Jupiter7]

I'm amazed that you can get that boolit to feed. My Savage bolt actions chokes hard on the HM2 Harris design and the meplet on that is only .155.

I actually have shot a ton of these, noe copy 311-165, drops 170grs. Had to play with OAL to get reliable function. Loaded short, they tend to jump forward in the magazine and turn into a 3 point jam requiring bolt lock and drop of magazine to clear. Loaded long to mimic .223 case neck, they feed easy. I load mine over 13.5grs of lil gun, 1650fps in 10" barrel, prints sub moa on paper. I'd bet it's a hammer on hogs and deer. I've shot it at a cinderblock, results are impressive.

[blackoutsteve]

What is the best .300 blkout mold?

[nitrohuck]

What is the best .300 blkout mold?

Most all of the LEE molds in .30cal will run in the blackout, as long as you can get them to chamber (some of the AR's don't like big meplats)

The round nose and spitzer nose designs run very well for most, with one of the most common designs being the C312-155

I have a C312-185gr that might work well, but the 155 is tried and proven in many people's rifles.

I also have on hand a NOE 314-129 mold that I can't wait to try out in the 300BLK, this boolit comes out to ~134grs without gas check and lube, and should be great for pushing 2k+ fps

[Jailer]

I also have on hand a NOE 314-129 mold that I can't wait to try out in the 300BLK, this boolit comes out to ~134grs without gas check and lube, and should be great for pusing 2k+ fps

Hurry up and get some of those cast and loaded, I can't wait to see the results. :grin:

[nitrohuck]

Hurry up and get some of those cast and loaded, I can't wait to see the results. :grin:

My brass from Grumpa just arrived a few hours ago, I'm leaving work soon to start loading them up! Boolits have been cast, sized, GC'ed and tumble lubed, so they're laying in wait ;)

Biggest question for these boolits will most likely be OAL... when seated to the crimp groove they are VERY far away from the lands, however it might not be such a big deal... It will be interesting to see how/if accuracy changes when seated longer/shorter.

[doctorggg]

I actually have shot a ton of these, noe copy 311-165, drops 170grs. Had to play with OAL to get reliable function. Loaded short, they tend to jump forward in the magazine and turn into a 3 point jam requiring bolt lock and drop of magazine to clear. Loaded long to mimic .223 case neck, they feed easy. I load mine over 13.5grs of lil gun, 1650fps in 10" barrel, prints sub moa on paper. I'd bet it's a hammer on hogs and deer. I've shot it at a cinderblock, results are impressive.

I know all guns are different but can you list your OAL?
Thanks

[Jupiter7]

I know all guns are different but can you list your OAL?
Thanks

Actually not a gun problem, mostly a magazine issue. Don't have notes with me, at work, but I believe short was around 2.06, that's with first lube groove just above case neck. Long loading was bottom of 2nd drive band even with case neck if I remember correctly.

[sunburn]

I have an RCBS 7.62-130-SPL 2 gang that I cast for the Blackout as the 130gn j bullets shoot/group fine in the 16" barrel. The OAL was 2.11. There was not enough crimp to hold the bullet tight enough to not loosen in the mag. Is there a percentage of overall length of the bullet for a proper crimp or is the crimp not tight enough? The bullet is .95 long and .20seating depth. Sorry to the OP on the hijack.

[Jupiter7]

I have an RCBS 7.62-130-SPL 2 gang that I cast for the Blackout as the 130gn j bullets shoot/group fine in the 16" barrel. The OAL was 2.11. There was not enough crimp to hold the bullet tight enough to not loosen in the mag. Is there a percentage of overall length of the bullet for a proper crimp or is the crimp not tight enough? The bullet is .95 long and .20seating depth. Sorry to the OP on the hijack.

Not familiar with that particular boolit. But neck tension is what should be holding the boolit in the case neck. I usually start loading a new boolit in 300blk with with GC/ base even with bottom of case neck and move out from there. I've loaded a few jacketed bullets (Sierra pro hunter 125gr) that are well up the case neck and have seen no ill effects on brass or accuracy.

[nitrohuck]

I have an RCBS 7.62-130-SPL 2 gang that I cast for the Blackout as the 130gn j bullets shoot/group fine in the 16" barrel. The OAL was 2.11. There was not enough crimp to hold the bullet tight enough to not loosen in the mag. Is there a percentage of overall length of the bullet for a proper crimp or is the crimp not tight enough? The bullet is .95 long and .20seating depth. Sorry to the OP on the hijack.

Most likely you are not seating that boolit deep enough into the case for it to have any sort of solid neck tension...

My NOE 312-129 boolit, when seated to the crimp groove, measures an OAL of 1.900"... as a (general) rule of thumb, you want to have a bullet's diameter's worth into the case neck, so .308" in... I think your problem is you have far, far less than that in the neck of your case, and only one driving band to provide tension. I have never dealt with the RCBS 762-130SPL but the profile doesn't seem to be drastically different than my NOE mold, perhaps a little longer but not by much... I was going to attempt to load my boolits out to 2.000" and that is pushing it,


EDIT: Also that bullet drops @ .309" and might be a little small for your 300BLK barrel, many of which like .310-.311", but that is not any sort of steadfast rule,

Double Edit: Your boolit's nose is actually .100" longer than mine...

[sunburn]

Most likely you are not seating that boolit deep enough into the case for it to have any sort of solid neck tension...

My NOE 312-129 boolit, when seated to the crimp groove, measures an OAL of 1.900"... as a (general) rule of thumb, you want to have a bullet's diameter's worth into the case neck, so .308" in... I think your problem is you have far, far less than that in the neck of your case, and only one driving band to provide tension. I have never dealt with the RCBS 762-130SPL but the profile doesn't seem to be drastically different than my NOE mold, perhaps a little longer but not by much... I was going to attempt to load my boolits out to 2.000" and that is pushing it,


EDIT: Also that bullet drops @ .309" and might be a little small for your 300BLK barrel, many of which like .310-.311", but that is not any sort of steadfast rule,

Rule of thumb for bullet diameter is what I thought as it is the same for a bolt to thread ratio. As far as .309 a bit small, a 3rd layer of Hi-Tek will help if needed.
The first round did not feed we'll as the boolit was too floppy, it separated from the case and flung powder all over the lower when extracted, leaving the boolit chambered. Boolit came out easily, but a check of the rest of the cartridges revealed my lack of loading talent, exceeded only by my quality control. The sub sonics ran fine from the Lee/Midway mold, harder to screw-up.
Input and advise much appreciated!

[nitrohuck]

Hurry up and get some of those cast and loaded, I can't wait to see the results. :grin:

I've posted my First range report posted in a new thread here on the forum!