[St. Phatty]

I was at the range this morning.

Among other things I was test firing some 300 Blackout bullets I loaded.

125 grain bullet. Normal factory bullets are 150 grain, 110 grain (2360 fps), and 220 grain (subsonic, 1000 fps).

Gunpowder: Loading a little aggressively - Max + and Max ++. Using Winchester 296.

The 300 Blackout is like a 44 Magnum with a handle, in rifle form ... about the same amount of powder. They use a Magnum pistol powder for a case about 2/3 the volume of a 5.56. A little over a cubic centimeter. Not a lot of room.

Loading by Volume because my scale crapped out and I'm waiting before I spend $$$ on another one.

So all I expected was decent shooting at 100 yards. And a serious bullet drop at 200 yards.

Instead, it shoots flat at 100 yards - and up about 1 1/2 inches at 200 yards. I set the scope so that 'zero' is at 100 yards.

It's like stepping on the gas and your 4 cylinder sedan is behaving like an AC Cobra.

The Max+ bullet was loaded to the shoulder, so, a little air-space.

The Max++ bullet was loaded above the shoulder - no airspace. Though it had more powder, it appears to shoot slower, less flat.


Completely mystified.

The lowly 300 Blackout is shooting flatter than factory 5.56 55 grain bullets (which go about 3200 feet per second.)

And flatter than the 308 (150 grain bullet @ 2800 fps.)

Now I want to load 296 powder into my 308

[Swamp Thang]

Hey St. Fatty I own a nice Steyr Pro Hunter chambered for 308 Winchester, but my ballistics know-how is pretty much non-existent. Your words read like those of a seasoned rifleman who can shoot the proverbial hairs off a flea's ass, with apologies to Clint Eastwood, so, I'm pulling up a chair to follow any discourse that ensues under this topic.

[CoCoSativas]

Love guns but don't know more than how to operate them, maintain, and what's good and what's not.

I used to own a 1911. Big no no up here because it wasn't registered and I didn't have a pal... (canadian possession license) so I got rid of it rather than go to the can. I'll probably go about it the right way soon. I was pretty wild a few years ago

Interesting question though I'm curious. I find ballistics fainting.

[St. Phatty]

As far as the 300 Blackout goes, I put the same scope on a 5.56 with a 16 inch barrel, which shoots VERY flat. It was up 2 inches at 25 yards, so it would be up 8 inches at 100 yards, before considering bullet drop ... which is close to non-existent for the 5.56 at 100 yards.

Basically shooting up in the air and coming back down. That would explain the seemingly wierd infinite-energy 300 BLK results.

The top rail of the 5.56 is not the same as the top rail of the 300 Blackout, although they have been close in the past (when I transferred a scope between them it didn't need much re-zero'ing.)

Anyway, it's interesting that with a little trigonometry trickery, I can persuade a bullet as slow as the 300 Blackout to shoot accurately at 200 yards. That day, far more accurately (sort of) than the 308.


However, if we can draw an analogy between a rifle barrel and the human digestive system, I think the 308 needs a longer intestine (barrel.)

It is ferociously loud, and with some bullets literally lifts the front of the bullet off the front shooting rest (hopefully, AFTER the bullet has exited the barrel, but still !)

Also with a ferocious recoil. I use a sock full of sunflower seeds as a shoulder pad.

So if we go back to the disgusting metaphor, the 308 with the 20 inch barrel has a bad case of explosive diarrhea.

The gunpowder is "not fully digested" - it is still accelerating when the bullet leaves the barrel. The cloud of smoke that is chasing it out should ideally expend most of its energy pushing the bullet. Instead it is spreading good garden fertilizer (potassium nitrate and sulfur) all over the infield. (Why isn't the grass greener there ?)

Long story short, to buy a longer barrel - OR - to use a faster burning powder, in amounts that the gun can handle.


One of my references when I make this judgment is the difference between the 16 inch 5.56 and the 24 inch 5.56. The 16 inch is louder and has more of a kick. The 24 inch shoots further flatter & (I think) faster.