300 BLACKOUT ?s

[STORMINORMAN]

1st time for this caliber. Have a bunch of M-80 style 147gr FMJ (NEW: Not pulls) to reload (for range use) a bunch of 147gr FMJ ammo from LA Ammo/Freedom Munitions I bought back when ammo/prices were still REA$ONABLE...

Realize the OALs for these bullets (and the factory ammo, as well!) will vary considerably: some bullets longer than others, etc. Also re-loading these to an identifiable point on the cannelure is probably going to establish acceptable accuracy and consistant velocities in the target/range (around 1700 fps).

Using WIN296/H110 in what is a generally accepted 15.3gr start load for an approximate 150gr bullet. OALs in the 2.140"+ area. They look a lot like the factory stuff.

The problem I really have with the published load data for 150gr bullets that ought to be more precision (specifically, the Hornady Interlock SP) also seems to vary considerably. The Hornady book has ALL their 150gr bullets with an OAL of 2.220" & powder at 12.7gr START @ 1500fps, 16.0gr MAX @ 1800fps.

Hodgdons has 14.6gr START @1725fps, 17.2gr MAX @ 1971fps for the Hornady 150gr IB with an OAL of 2.235".

LYMAN has the Hornady 150gr FMJ-BT with 14.5gr START @ 1911fps and 16.2gr MAX @ 2060fps using an OAL of ONLY 2.075"(!)...?

In my way of thinking that's a just a huge difference in OALs & fps.

The bullet has a cannelure as well: but, at the Hornady OAL it is nowhere near the rim. I have not loaded any to the LYMAN OAL, but I bet it is pretty close to the cannelure. I recognise these bullets are not specifically designed for the 300 BLACKOUT vs. the many other possible 30 cal. applications, but...

It just looks weird to load these bullets that far from the cannelure: perhaps I just have loaded too many revolver bullets?

Any advice would be appreciated. I'm not concerned too much about the 147gr FMJs as I can always work up. Many internet posts show loads in the 17gr range of WIN296/H110 for these M-80 types. Don't want or need to go that fast!

Thanks in advance for your kind consideration.

Cheers!

 

[Abflyboy]

Bolt action or gas rifle?

This is important for a lot of reasons ...

.300 Blackout is an interesting critter in a gas rifle when you are reloading.

 

[Ivan the Butcher]

This cartridge is a almost great AR-15 round and a mediocre bolt round. In Bolt guns you can use the cannalure for setting the COAL. But in AR type guns the COAL is dictated by AR-15 Magazines!

The original parent round is 221 Fireball opened up to 30 caliber. I have made almost 800 from 223/5.56 brass, trimmed to length. These will be less consistent that factory or 221 based cases, but close enough is just that!

The big advantage for this round isn't to be a 308 Win LITE or a 7.62x39 knock off. This cartridge shines with 200gr + bullets loaded subsonic and with a sonic suppressor (aka silencer). But even then you still only have 45 ACP knock down power with a range of less than 200 yards.

Ivan

 

[ArchAngelCD]

What is the COAL if you crimp into the center of the cannelure? I know you said the bullet isn't specifically for the 300 Blackout but you usually get the best results when using the crimp groove supplied by the manufacturer. This is just my opinion but I think it's a good choice.

 

[Ivan the Butcher]

What is the COAL if you crimp into the center of the cannelure? I know you said the bullet isn't specifically for the 300 Blackout but you usually get the best results when using the crimp groove supplied by the manufacturer. This is just my opinion but I think it's a good choice.

That all depends on the bullet, that is why is varies so much in loading manuals!

Ivan

 

[Ivan the Butcher]

My method of making 300 BO brass from 5.56. This is a lower pressure round (at least in sub sonic) so this is where you can use up 223's with split necks and othe defects, but you still need the rim face in good shape.

The order in which you do the steps can be changed, but this is the fastest way I have been able to come up with. I usually do 200 to 300 in a batch.

1.) I start with fired brass that is mud free. I use a small band saw and cut the neck and shoulder off about 1/10 inch longer than the finished BO round. If no band saw is available a Dremel Tool with a cut off wheel is a good bet, a hack saw will do, and even not trimming until later will work!

2.) Lubricate and FL size in a 300 BO sizer die! You will be forming a new shoulder so expect some effort, you may have crimped in primers so take precautions. about broken primer pins.

3.) This is when I clean my brass. I use the wet tumble with stainless steel pins method, mostly because it gets the inside and the primer pockets "Like New" Clean.

4.1) Trim to length. Easier said than done, but whatever you do think drill power! The Lee system is very affordable. I use a Forrester Case Trimmer. (standard length works fine) with a drill adapter, and one friend hand turns them on a Hornady (but he's retired and needs something to do!)

4.2) Deal with case mouth burs! inside and out.

5.) Now is the time to deal with primer pocket crimps. I use a RCBS case prep center with a small pocket crimp ream, then use a RCBS primer pocket swager. I find that about 1/4 need a second set of treatments, But I only have 15 seconds or so in each case. This is the time to prime the dry cases, in case you need to redo some.

Now you are back to standard small rifle reloading.

Ivan

 

[reddog81]

OAL will depend on bullet profile, magazine and firearms to be used. I generally like to load as long as possible.

Velocity will be dependent barrel lengths. Anything from 8 to 16” is common in .300 blackout. There could be a 200 FPS difference with the same ammo in different guns.

 

[Hair Trigger]

This cartridge is a almost great AR-15 round and a mediocre bolt round.

But even then you still only have 45 ACP knock down power with a range of less than 200 yards.

Well, a .45 has plenty of knock down within its effective range, which is a lot less than 200 yards. Mid-sized bullets (155 grain) have equal or better performance at 200 yards than a 30-30 because of better BC and SD. 125 grain bullets are popular with hog hunters around here.

I built my Blackout because I wanted a larger, heavier bullet than .223 offered, and it runs with anything from 110 to 210 grains. I generally load 125 and 155 grain, I don't hunt with it but I have done some CQB matches with it. I never intended it for longer ranges than about 200 yards, I have other rifles more suited to 200+.

 

[STORMINORMAN]

To answer some questions...

I have both rifle (16") & pistol (10") uppers for the 300 Blackout.

Realize that some bullets may be virtually identical except for one having a cannelure, and that, with some exceptions (i.e., the 135gr FTX), there are really pretty few supersonic bullets actually designed with this specific caliber in mind.

I'd estimate loading either Hornady 150gr bullets to 2.075" would put them near the cannelures. What I was concerned about was loading (for example) the same 16gr of WIN296 at 2.075" vs. 2.220"...? That's such a huge (as in 0.145") difference in OAL (and pressure?) for me, a reloader who primarily concentrates (and has but a modicum of rifle experience?) on the pistol calibers.

CHEERS!

P.S. In post #3 I think Ivan was referring to sub-sonic & suppressed heavier bullets (200gr) which are used for specific hunting (OINK!) and/or defensive purposes.

 

[rockquarry]

I'm not being critical of this cartridge, one I've had no experience with it. However, how many are aware that it's pretty easy to load the 7.62x39 with cast (probably jacketed as well) bullets of 200 grains to about 1,700 fps or maybe more? I'd have to look through my records for exact figures. The 7.62x39 can accurately handle cast (and again, probably jacketed) bullets up to around 220 grains and with good accuracy.

I'm really no advocate of the the 7.62x39 as there are far better cartridges for most uses, but I've seen good accuracy and velocities working with the cartridge over many years.

 

[Golphin]

The advantage to a 300Bo vs say a 308 Winchester in a AR is you can build one much cheap using the same lower and upper as the 223 only with a different barrel. I have loaded al kinds of bullets for 300BO not worrying about cannelure just overall length.

 

[Nevada Ed]

So you went out and got yourself a new toy...............

They are a fun round out of a rifle.
I got to shoot one in Utah along with a 6mm GT wildcat at a home made range, out to 1,500 yards.

Back then brass was hard to find and we searched the area until we found all the spent cases.

The owner was still waiting for his surpresser but even without it, I did not think that the report was that bad.
Only problem was the time to load the magazines vs the amount of time it takes to empty them !!

Have fun with the new rifle.

 

[Rogeronimo]

Any advice would be appreciated.

Accurate Powders warns to keep your mags straight, as under the right conditions, a 300 BO can headspace in a 5.56 chamber.

 

[STORMINORMAN]

Appreciate the Concern

Accurate Powders warns to keep your mags straight, as under the right conditions, a 300 BO can headspace in a 5.56 chamber.

I do use different magazines (Hexmags, in colors other than black) for 300 Blackout visits to the range.

Even worse could be a round loaded long and being "compressed" by the chamber...!

Cheers!

 

[Ivan the Butcher]

My 300 BO has Tan furniture, and the mags are all Tan for it too!
Since my 71 year old brother just bought his first AR, I physically showed him what not to do with my ammo! (Because I know he will be mooching mags and ammo!)

Ivan

 

[Nevada Ed]

Accurate Powders warns to keep your mags straight, as under the right conditions, a 300 BO can headspace in a 5.56 chamber.

Holly cow...............

now that would be UGLY, if it ever happened.