300 grain bullet

[oobray]

Does a 300 grain bullet exist in .308? I am really interested in this. From what I have read, and the math I've done a 300 grain bullet traveling at 900 fps would deliver over 600 lb/ft of energy. That's pretty impressive. Anyone know if such a bullet exists?

[sharky47]

I have never seen one, but I have never looked either......

I could make one and see how it flies, but there is not way in hell you could load it to AR15 magazine length, would have to be a bolt gun and the ogive would have to be configured so that the bullet wouldn't contact the rifling on chambering. I would imagine it would look like a really long semi-wadcutter.....

[Rikky Lee]

Semi wad cutter? (take a 240/250 grain SMK and round out the pointy bit until it looks like a 220RN???) Twist rate would be my concern regardless of shape.

[Artful]

Would it have any real advantage over the 240 grain sierra? The reason the 250 grain was dropped was to improve stability as I recall. If you made one you'd probably have to go to a faster twist like 1:6.5 as the length would be even longer than the 240's we can now get.

I mean really the easy was to get a 300 grain bullet is to increase the caliber - jump to a 50 and you can use 500 grains+ to increase your energy.

[oobray]

the reason I was asking is because the energy difference between 240 and 300 is pretty significant. I'm not really interested in going to the 50 because of recoil concerns. From the math I've done it looks like the 240 will probably be good on deer and 300 pound pigs out to about 250 to 300 yards. Is there anyone that has actually measure speeds of a 240gr at 300 or 400 yards?

[Fudmottin]

I expect all speeds are calculated. But it can be done. Shooting over a chrony would be a risky proposition. But building a ballistic pendulum to catch the bullet and lock at its maximum point of swing should be doable.

I can think of one way to make a 300gr bullet stable at 1:8 twist. Not guaranteed mind you. And it won't shoot from an AR because of seating depth unless you single load. Even then I wouldn't recommend it.

Make a full wad cutter hollow point. Make it hollow all the way down to the base with just enough in the base for the charge not to blow through. By pushing the mass to the outside, you will get a more stable bullet.

The 240 SMKs already tend to pass through game from what I've heard. Major penetration. So if you want more mass on target, you might want to look at the 458 SOCOM.

[Rikky Lee]

Won't be stable in a 1/8 twist.

Having spent a happy Sunday afternoon launching 240 SMKs around the place at different velocities I would say that the down range energy transfer is impressive. I vote to not stand in front of one on the off-chance it goes straight through.

[THE DOCTOR]

Powell river laboratories did make a some 280 grain powdered tungsten bullets for some government contracts but at $4 a piece that gets pretty pricey. Not all of us have the governments budget. DRT purchased the right to use Powell river labs tungsten bullets and make current loaded ammo but none that heavy. Most are around 200 grains.

[sharky47]

"Not all of us have the governments budget."

Ah, but we do - the "government's" budget is looted from our wealth, it has none of it's own......


If you have the means to lathe turn your own bullets, you could do a fin stablized projo - I have a brass .50 BMG fin stabilized bullet I designed and made somewhere in my desk drawer.

[Fudmottin]

How does it group?

I've considered solid copper projectiles. But so long as regular bullet noses are available, why bother?

[JFettig]

200 grains:
http://stuff.jfettigmachines.com/300w/turning/new6-08/tn_IMG_1267.jpg
pure copper, C145. Round nose, flat base, no hollow point, maybe hit 250-270 grains.

Jon

[Fudmottin]

Nice use of driving bands there. Should keep pressure levels safe and lengthen the life of the barrel.

I've seen artillery shells that only use one or two driving bands. Would that still work and save you some machining? Or are you trying to keep every last grain of material you can?

What's the story on the nose tips?