Any velocity data for 30gr .223?

[grampajack]

I was curious what a 30 grain bullet might do out of a 16'' barrel (.223/5.56). I've not been able to find any numbers though so I was wondering if anyone had some anecdotal data.

 

[Klint Beastwood]

I was curious what a 30 grain bullet might do out of a 16'' barrel (.223/5.56)

Not much.

 

[Klint Beastwood]

Also i would make sure first you have the right barrel to stabilize that light of a bullet flying at + or - 3,900 fps.
1-12 should work. a rough miller stability...i used .6 for length would put it at a 1.98
Bullet would go transonic roughly at 550y in a density altitude of 5442 and 90f.
Max PBR for 6in would be 250y. muzzle energy would be around 768 ft lbs.
This is all estimated through a ballistic calculator and the DA is in my area. Also the muzzle velocity will depend on the cartridge and actual velocity in THAT barrel.

 

[grampajack]

I'm just looking for a rough estimate on muzzle velocity.

 

[Klint Beastwood]

around 39,000 and subtract about 20 fps for every inch off 24" is a the rough estimate.

 

[grampajack]

around 39,000 and subtract about 20 fps for every inch off 24" is a the rough estimate.

I'm assuming you meant 3900? That's about what I was thinking.

The reason I ask is I had an idea for a home defense round that would work in short barrels with 1:7 twist. The idea is to take a solid copper 30 grain pill, but elongate it by making lightening cuts around the circumference. So it would only be 30 grains, but being copper instead of lead and having the equivalent of flutes cut in it, it would be the same length roughly as a 60-70 grain conventional bullet, so it would survive the 1:7 twist.

Another option would be to use a solid steel penetrator with a soft steel jacket coated in moly. Should accomplish the same thing and be much cheaper to produce. I couldn't make that on a lathe though, so I would have no way of testing it. The best I could do is make the penetrator and load it into a sabot. That would work for testing, but I doubt it would cycle from a magazine.

 

[Klint Beastwood]

I'm assuming you meant 3900? That's about what I was thinking.
.

haha yeah. good catch.
stability isnt the real issue when i was talking about it. the 1.8 barrel will stabilize about anything in regular bullet weights. the weight vs speed is probably going to be an issue in a 1/7. its not a issue of actual stability..its the round getting torn up in the barrel during the rpm's.
with low density copper bullets usually like slower twist as far as i remember.

 

[grampajack]

haha yeah. good catch.
stability isnt the real issue when i was talking about it. the 1.8 barrel will stabilize about anything in regular bullet weights. the weight vs speed is probably going to be an issue in a 1/7. its not a issue of actual stability..its the round getting torn up in the barrel during the rpm's.
with low density copper bullets usually like slower twist as far as i remember.

My only concern is that it survive the trip. Accuracy isn't a big issue, since it would be for HD. It would be nice to get good accuracy out of them, but it's not the priority.

 

[Klint Beastwood]

I'm going to be honest with you....with muzzle energy at in the 700 ft lbs area.....you might as well just use a .45 acp...at least the energy of hydrostatic shock will be higher...and i live in a warm area...so that about the best it gets.
other bullets like the green tips start to tumble after hitting things..body mass, wall, 4x4s drywall the works. they wont go any further than a normal handgun round.

 

[grampajack]

I'm going to be honest with you....with muzzle energy at in the 700 ft lbs area.....you might as well just use a .45 acp...at least the energy of hydrostatic shock will be higher...and i live in a warm area...so that about the best it gets.
other bullets like the green tips start to tumble after hitting things..body mass, wall, 4x4s drywall the works. they wont go any further than a normal handgun round.

Basically I'm looking for 5.7mm ballistics, for someone who say lives in an apartment. So roughly 10-12'' in gel and a gigantic expansion cavity. All that's needed is a lightweight bullet that can survive a 1:7 twist, so it's a plug and play thing that can turn any standard AR into a viable house gun where penetration is concerned. So it would be to an AR what #4 buckshot is to a shotgun.