.300 win mag: pursuing 4000 feet per second.

[asd9055]

Woooooooohooooooooo!!!!!

update everybody!!!!

got the chrono and got to shoot over it today. I am beyond pleased. I closed the muzzle brake, not sure if that actually makes the barrel an honest 26 inch but it's one of those savage brakes you can just twist to open or close. The point of impact shifted wildly from doing this, gonna chrono it again sometime with the brake open and if it's not losing much I'll just leave it open.

anyways….I'll just include the pics of the chronograph readings about 15 feet from the muzzle. I had a hard time believing it, would have been a skeptic in the past but folks such as @scope-eye and @ButterBean helped me believe in this kind of light and fast performance again.

again, the specs are Peterson brass, fed 215m primers, 89.5-90.0 grains of superformance (I wasn't as meticulous down to the tenth of a grain as i sometimes am) powder, lightly compressed under a 120 grain Barnes TAC-TX (initially designed for .300 blackout, we're going a lot faster haha) that is treated with hexagonal boron nitride.

no primer cratering, moderate flattening, no ejector marks on brass, no stiff bolt at all (operated easily with one finger, cases just lazily fall out). Upon resizing, no notable case length change, no web expansion, no discernible difference in primer pocket tightness from virgin brass.

I hate that we have to say this but obviously this is a warm load and i worked it up slowly and safely. This is safe and functional in my firearm, not to be assumed safe and functional in others. Start at least 10 grains under this and work up if you should choose to do so. We are adults here, let us be responsible for ourselves even as we celebrate with each other's achievements.

Be prepared to try and understand the embarrassing happy dance I did when I saw this…

Impressive
I am not an expert, but curious what is the effect on the barrel life?

 

[ButterBean]

Woooooooohooooooooo!!!!!

update everybody!!!!

got the chrono and got to shoot over it today. I am beyond pleased. I closed the muzzle brake, not sure if that actually makes the barrel an honest 26 inch but it's one of those savage brakes you can just twist to open or close. The point of impact shifted wildly from doing this, gonna chrono it again sometime with the brake open and if it's not losing much I'll just leave it open.

anyways….I'll just include the pics of the chronograph readings about 15 feet from the muzzle. I had a hard time believing it, would have been a skeptic in the past but folks such as @scope-eye and @ButterBean helped me believe in this kind of light and fast performance again.

again, the specs are Peterson brass, fed 215m primers, 89.5-90.0 grains of superformance (I wasn't as meticulous down to the tenth of a grain as i sometimes am) powder, lightly compressed under a 120 grain Barnes TAC-TX (initially designed for .300 blackout, we're going a lot faster haha) that is treated with hexagonal boron nitride.

no primer cratering, moderate flattening, no ejector marks on brass, no stiff bolt at all (operated easily with one finger, cases just lazily fall out). Upon resizing, no notable case length change, no web expansion, no discernible difference in primer pocket tightness from virgin brass.

I hate that we have to say this but obviously this is a warm load and i worked it up slowly and safely. This is safe and functional in my firearm, not to be assumed safe and functional in others. Start at least 10 grains under this and work up if you should choose to do so. We are adults here, let us be responsible for ourselves even as we celebrate with each other's achievements.

Be prepared to try and understand the embarrassing happy dance I did when I saw this…

I'm Totally impressed

 

[fmuguira]

Have to name it your 300 "Swift" !

 

[Calvin45]

Impressive
I am not an expert, but curious what is the effect on the barrel life?

If you shot these all the time I'm sure its bad. Once I get this dialed in real good it's for hunting and that's about it so it's a moot point.

 

[Calvin45]

I'm Totally impressed

That means a lot coming from the LRH velocity king haha! I had told myself to be realistic and not get my hopes too high, to know that I might not get any higher than 3800 or so and that id have no reason to complain about it, that there's not really that big a difference…but in my brain there is (even if a deer wouldn't notice). As someone in another thread said "3950 is not 4000!" When I fired off the first over the chronograph and saw the first number was "4" my heart got going a little fast…I've never loaded anything this fast before.

 

[cohunt]

Can we get a ballistics gel test on that 300bo bullet at those speeds? I wonder if the base still holds up?

 

[Calvin45]

Can we get a ballistics gel test on that 300bo bullet at those speeds? I wonder if the base still holds up?

I've never made ballistics gel. I do plan to shoot into a bunch of water jugs and recover the bullet. It won't surprise me at all if the petals shear off

 

[cohunt]

I've never made ballistics gel. I do plan to shoot into a bunch of water jugs and recover the bullet. It won't surprise me at all if the petals shear off

Try wet newspaper instead of water jugs

 

[Veteran]

Wow, zippity do da. Yes, may new barrel on order. Pushing the envelope for sure. "Absolute" hammers may be less hard on your barrel and get even higher velocities? Just a thought.

 

[Veteran]

Oh and yeah, along with that new barrel, I would order some copper removal solvents.....its gotta be shredding some off the
bullets each pass down the drag strip......sorta like peeling out with a 426 Hemi.

 

[Veteran]

With absolute hammers and a 48 inch barrel, you can probably do 4700 fps?? So, ya gotta consider that on the new barrel order....

 

[ButterBean]

Can we get a ballistics gel test on that 300bo bullet at those speeds? I wonder if the base still holds up?

It's been done with the Hammer 101 HBO's , it holds up,

 

[Calvin45]

Oh and yeah, along with that new barrel, I would order some copper removal solvents.....its gotta be shredding some off the
bullets each pass down the drag strip......sorta like peeling out with a 426 Hemi.

I'm really curious to see how the hexagonal boron nitride in the barrel and on the bullet affects copper fouling. I had initially wanted to use an enduron powder for the copper eraser function but none of them would get the kind of speed powders like superformance and rl17 are capable of in cases like this with bullets like this.

 

[Calvin45]

It's been done with the Hammer 101 HBO's , it holds up,

Good to know. I did also shoot them through an 18 inch thick stump so….