Breaking the 4000fps barrier...

J

Jamie Young

New member
I've noticed on a few of my reloading books some of the .223 powders can get close to 3300 fps. My lyman book says it was with a Colt 20in barrel. I've been wonder if its possible to have an accurate .223 that can achieve 4000fps. It seems there are quite a few calibers out there that can get over 3000fps depending on bullet weights but nothing faster. Is there an Aero-dynamic barrier at that velocity or is it just a Maximum case pressure limit?
 
I imagine it would be possible to push a .223 to 4000 fps+, though if it would be within pressure standards, I'm not sure.

Winchester ammo sheets show their 22-250 40 and 45 grain pills going at 4150 and 4000 fps respectively; at the muzzle, of course. 220 swift also shows 4000+. I imagine with some good reloading, you could push these things far past the factory speeds...
 
220 Swift with a 50 grain or less projectile. I do not think we could smith an AR to to this BUT ? Perhaps a 223 or 224 sabot for a .17 round might come along and we might go for 5000 fps. Remington had, or has, a sabot round for 30 06 with a 223 projectile that was humping around 5000 fps. You start running into a chamber pressure limit problems.
 
I can hardly imagine a Sabot out of a 30/06 flying 5000fps hitting anything very well at 300yds? I'm basically talking about the .223 with a 55gr bullet breaking 4000fps with something like an AR or Mini 14. The 3300fps were with 55gr bullets in my book. Is there a terminal Velocity for the modern 55gr boat tail? I assume the Boat tail is the fastest design for a rifle bullet?
 
You must have a stout bullet if you are gonna shoot at or over 4000 FPS.
Most bullets start coming apart around 4200 fps and up.
Some of the gun mag writers have observed this in their quest for speed. The bullets never made it to the target in in one piece.
They also had problems with errant readings on their chronographs.
Saboted bullets can usually easily acheive these speeds. A 55 grain .223 in a 30.06 will do it.

IF you want speed the easiest and safest way to do it is with the sabots. They can be very accurate if one takes the time to ensure that they are absolutley concentric.Most people dont take the time to do it right, as a result they get poor results that they blame on the sabot. The instructions state that they must be less than .001 runout to be accurate. Most that Ive checked with dial indicator have been in the .003-.004 range.
Usind bench rest collet dies will usually solve the problem.
 
I clocked some of my 55gr. Ballistic Tips at 4200, in my .243 Rem. VLS. Accuracy was just fine. I backed the load down to about 3800 fps, which is fast enough for my purposes, and not as damaging to the barrel/throat.
 
I think most agree that around 4500 fps is about the limit for our current powders, not because of chamber pressure (just build a bigger case) but because depending on the type of powder your only looking at an expansion rate of 5000-6000 fps. Even a very light projectile has to have some friction going down the bore or theres no pressure to push it, so that may explain the 500 or so FPS we can't get back from the speed the powder is expanding. At least thats the way I uderstand it.

If anyone has a link to different powders exapansion rates I'd be interested.

Thanks, Blue Duck
 
4000 fps

Every shot you fire at 4,000 feet per second makes you a lot closer to eroding a good barrel. It's been that way for years.
 
SodaPop, I imagine that around 3,300 (roughly) with a 45- or 50-grain bullet is near SAAMI limits. I'm too lazy to go hunt for the exact data, but it oughta be around 51,000 psi to maybe 53,000. You may well exceed this, up into the primer-flattening range of pressures, but it sure would not at all be practical.

I believe Remington advertised their '06 Accelerator round at 3,480 ft/sec.

Per Phil Sharpe's "Complete Guide To Handloading": In 1937 the Springfield Armory was experimenting with very high velocity. On February 12, they got 5,122 ft/sec. They next achieved 7,100, and at press time of the book, they had recorded a velocity between 8,500 and 9,000 ft/sec.

Capt. Sharpe stated that up to 7,100 ft/sec, "normal Springfield pressures" were used. He states no signs of abnormal pressure in one cartridge case in his possession.

No info was given as to caliber or bullet weight.

One thing to remember is that no projectile can travel faster than the pressure wave which drives it. Smokeless powder does not explode; it burns very rapidly. It is the pressure of the expanding gases from combustion which propel the bullet. Somewhere there's a discussion of pressure-wave velocities, and probably combustion temperatures, as well.

:), Art
 
4000FPS ? Good by Barrel! I have Win,70 in .223 Just replaced my barrel last year. Had about 6000rds and 10yrs on it. I keep my hand loads around 3200Fps with 55gr bullets.
 
Sodapop: I don't load up any hot loads for my AR. I typically keep 55's at 2800 or so. (16" barrel) I didn't mean to load that .243 up to 4200; was extrapolating some load data and just loaded 'em a little hot. As I said, the 55's @ 3800 do a fantastic job.

Just curious: What the heck does steam have to do with this thread?
 
WalterGAII, Dangus gonna build a steam-gun!

Muzzle velocity won't be all that high, but Lordy, how big a projectile!

:), Art
 
Ok I have another Question to pose. If you could achieve 4000fps with a 55gr steel bullet out of an M16 wouldn't you be able to increase the range by another 300yds or so? I know most of you would ask WHY but a lot of folks when comparing the .308 to the 223 get into the range debate. How much better has Gunpowder become in the last 10yrs?
 
Is there a chart where I can find data about how fast various liquids, water, vegetible oil, petroleum, etc expand as they boil off?

I'm not building a steam gun, but I have a very interesting idea which I'm not gonna discuss till I've had time to try it(and maybe to patent it)
 
To begin with, I'd never shoot a steel bullet out of one of my rifles.

If you want to play around with hypotheticals, there are a number of ballistics programs around where you can just plug in your imaginary numbers.
 
You must log in or register to reply here.
Back
Top