300 blackout recipe

[silverback13]

I am thinking about getting into 300 blackout. What recipes have members come up with that are consistent and reliable?

110 grain on up?

Comments / recommendation?

[scottfire1957]

why not trust a reloading manual?

[silverback13]

I hear but reloading manuals don't give real world experience. I am just trying to tap into the wealth of knowledge and experience of this forum. Why reinvent the wheel with a resource like this at your fingertips.

[Digital Dan]

If you want to "tap into the wealth" you might want to consider letting us know what platform you are considering, if you plan to cast for the cartridge and maybe whether or not you plan to go full tilt or fiddle with subsonic loads.

[A pause for the COZ]

Here I can help you. 300 BO is pretty hard to screw up.
At least for supersonic 150gr cast and 125gr jacketed for an AR15. Try H110, 296, RL-7 or any comparable burn rate powder.
Any usable load for that bullet weight is going to be 90% fill or above. So your not going to over charge it.
Usually in that powder range you will be 16 to 17.5 gr loads. Start low and work up to the one that works best.

Cant help with subsonic loads and there is a danger with the use of big heavy fat bullets and a fast pistol class powders.
You can over charge those so be careful.Start with the easy ones and learn your way up.

[runfiverun]

knock it off.
he just asked a question.
being a Dick about it ain't helping.

[scottfire1957]

Here I can help you. 300 BO is pretty hard to screw up.
At least for supersonic 150gr cast and 125gr jacketed for an AR15. Try H110, 296, RL-7 or any comparable burn rate powder.
Any usable load for that bullet weight is going to be 90% fill or above. So your not going to over charge it.
Usually in that powder range you will be 16 to 17.5 gr loads. Start low and work up to the one that works best.

Cant help with subsonic loads and there is a danger with the use of big heavy fat bullets and a fast pistol class powders.
You can over charge those so be careful.Start with the easy ones and learn your way up.

You used which reloading manual for that?

[scottfire1957]

knock it off.
he just asked a question.
being a Dick about it ain't helping.


He's NOT lazy? Him insulting my wife makes ME the dick?

[Naporter]

As far as heavy subsonics goes, it's quite difficult to overcharge when using appropriate powder. The case capacity is so heavily reduced by the bullet's massive size. In the case of many of the heavy bullets, the bullet is longer than the case itself, leaving very little internal volume.

Hodgdon listed my current loading with 4227 as having a max load (to remain subsonic) as 9.8. It only generates 25,800 psi, well below max. But beware, as case capacity opens up with the lighter bullets, it becomes increasingly easier to overcharge.

[Naporter]

He's NOT lazy? Him insulting my wife makes ME the dick?

Hes not being entirely lazy. Manuals rarely have data for cast boolits in this caliber.

That said, you're both acting immature.

[scottfire1957]

Hes not being entirely lazy. Manuals rarely have data for cast boolits in this caliber.

That said, you're both acting immature.

Nananana boo boo;)

[silverback13]

Hes not being entirely lazy. Manuals rarely have data for cast boolits in this caliber.

That said, you're both acting immature.
You are correct sir. I digress. Thanks to everyone who actually contributed. I am just looking for input as to what loads have worked for some and what loads haven't. I am researching this round and trying to decide if it is going to be worth the money to invest in. Thanks again.

[runfiverun]

IMO.
in a bolt gun it is a neat little round, that is easy to work with and is very flexible.
in a semi-auto you need to do some homework on gas tube length and become limited somewhat in what you can do.
I have a couple of the bolt gun versions and work with a wide variety of bullets and boolits.
I size the 98gr rnfp from rcbs down to .310 for a light pop load, I load the Hornady V-max and the sierra 110's as well as the nosler varmageddon up into the 2400 fps area for varmint hunting.
I use the 311358, the rcbs 165 gr. silhouette, the ACE 140, Hornady 200's, the LEE 230 gr.,
and have tinkered with a few others, with more to come. [ I need a 130gr jacketed for close in deer hunting] and have used all kinds of powders from 700-X up through H-110
I have a nice 180gr hollow-point I make from 5.7 brass that will probably see some range time eventually.

for the AR rifles I have only worked on 2 loads, one sonic and one subsonic, so I'm a little limited with them.

[Naporter]

I've played with it in a short barreled AR (10.5 in) and you should be aware that it excels in short barrels. Even a 16" is more than is necessary. The 110 Varmegeddon R5R mentioned does well in my rifle with 19.8 grains of H110 in converted cases and CCI SRM primer. The SRM helps powder burn rate and does well to ensure consistency in the short barrel. This loading is a tack driver in my rifle with that little bullet flying out at just over 2200 fps. The only problem is that dirty powder gums up the action pretty badly.

[silverback13]

I've played with it in a short barreled AR (10.5 in) and you should be aware that it excels in short barrels. Even a 16" is more than is necessary. The 110 Varmegeddon R5R mentioned does well in my rifle with 19.8 grains of H110 in converted cases and CCI SRM primer. The SRM helps powder burn rate and does well to ensure consistency in the short barrel. This loading is a tack driver in my rifle with that little bullet flying out at just over 2200 fps. The only problem is that dirty powder gums up the action pretty badly.
I would like something in that range to at least come close to 7.62 x39 performance. I have a line on a 10.5 barrel. Subs I was thinking 200 grain. I hate to give up weight savings of 223 but like the 30 cal round.

[Reddirt62]

I can tell you this...it is a fun caliber to load for....lots of options. I experiment with this load more than any other I have. 110 nosler Varmegeddon is an excellent bullet....I have a fun sub with it but bolt gun only. The main issue with the AR platform and cast is the bullet needs to be pointed to cycle reliability, so if casting look at 762x39 molds or similar.

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[BUCKEYE BANDIT]

https://op1.ec.tc/978-550-ffffff/opplanet-lyman-handboook-reloading-for-the-ar-rifle-9816045-main.jpg

[Naporter]

I have a Lee 230 mold and an NOE 247. The first is pointed but the latter has a 0.2" meplat and cycles fine. I've got Maker 200 expanding subsonics working reliably too, and they have a meplat that's only slightly smaller. It's a good bullet by the way, but pricey at $0.84 each.

[runfiverun]

I'm using AA-4100 under the varmageddon it's prettydarnclose to 2400.
I'd maybe look at it for the AR's if H-110 is burning a bit dirty.
under the 100-165 cast I'm using Data-9 [aa#9] powder.

when I done the load work ups for the AR [180-208 jacketed] I used 4227, I never did 'look to see' if it would work with the lighter stuff.

[popper]

I am on my third AR BO, 2 carbinesa and a 10" pistol. The pistol is 1:8 with pistol gasd, not sure I really need it as I don't shoot subs. My favorite is the 18" 1:10 carbine that runs a 145gr DFP PB @ 2100. Plenty for deer, pig or paper. I gave the 1:7 16" carbine to SIL, he uses UMC 120gr. Been playing with 170 PB & 185gr GC RD style in the pistol, ~1600 fps & up. Last 2 moulds were for 30/30 where they work good. BO is cheap and fun to shoot. GS really likes the BO but I think he played with it and had to get some one to fix it. Daughter likes the supresssed 223 better.
191911191912

[Naporter]

I don't usually use powders from other manufacturers. I've had good luck with Hodgdon and have stuck by them for a while now. The H110 is tolerable when running without a can, but it gums up the action horribly bad when suppressed since the action is so heavily overgassed. I'll have to have a look at that powder and see how I like it.

I've had good results with 4227 with 150 grain interlock soft points too, running 16.5 grains for velocity around 1700 out of the short barrel IIRC. I've gotten away from these though due to the lackluster performance and prefer the 110's or heavy subs.

Those Maker bullets would be wicked to hunt with, no plinking though.

[runfiverun]

I have very few hodgdon powders on hand.
I used to use them a bit more, but get better performance and accuracy out of Accurate and Alliant.
I probably wouldn't even miss Hodgdon if they went out of business.

[Elkins45]

One interesting phenomenon I will relate is that often times you can get equivalent velocities with heavier bullets using less powder because the big bullet takes up so much space it dramatically increases loading density. I was experimenting with subsonic loads using 300-MP powder with both 200 and 240 grain bullets. The 240 actually took a full grain less powder to achieve the save velocity as the 200.

The Blackout presents a lot of variables to work with.