.223 powder puff loads but maximum charge

[Woody3]

Hi all,
First off I'm trying to work up a load for my 16" 1 in 9 twist AR. It has 150 rounds through it. 100 of those were factory loads that cycled and shot well.

Right now I have a stock pile 16lbs of 2400 so I've been trying to work up a plinking load using that powder.
I'm using hornady 55 grain projectiles and cci small rifle primers. I started load production at 12.8 grains of the 2400 and worked up to 14 grains of 2400 (which is the max recommended load). I had two separate groups loaded at .2 grain increments. One group was at 2.220 and the other group was at 2.29 col.

Today I tested the loads and to my surprise, none of the rounds would eject and cycle in a new round. Essentially the AR turned into a single shot rifle.
Along with the above info, the recoil was very light and in fact felt weak.
All rounds were drop checked in a case gauge.

My question is: should I decrease the col to increase pressure so the rifle will cycle or should I increase the powder charge?

Thanks,
Woody


Keep your head low and your powder dry.

 

[Hondo 60]

I just looked on Alliant's website & they don't even have a recipe for 223 Remington using 2400.

So in other words they don't recommend that you use 2400 for that round.

A powder like RL-15 or Hodgdon's Varget are MUCH better choices.

2400 is better suited for handgun applications.

http://www.alliantpowder.com/reloaders/Powder.aspx?powderid=9

 

[Woody3]

I know what alliant says now, but it hasn't always been that way. they changed. Hmmm


Keep your head low and your powder dry.

 

[35 Whelen]

Go to the Cast Boolit website and do a search. I can 100% guarantee you that someone over there has done what you're trying to do. I've found that some of the folks over here bite there nails and have trmors when you talk about loading a powder in a way they don't understand.
I use WAY more pistol powder in my rifles than I do rifle powder. Otherwise I'd have gone broke long ago as much as I shoot.

Here, let me get you started: Light AR loads

35W

 

[LiveLife]

2004 Alliant Reloaders Guide has limited load data for .223 Remington and 2400.

 

[Woody3]

Thanks guys. I'll check those out in the morning.

Woody


Keep your head low and your powder dry.

 

[Captaingyro]

Alliant did publish those loads, but it didn't publish them as AR-15 loads, or even semi-auto loads. While they will push a bullet out of a barrel, they may not be capable of cycling an action. (And pushing a bullet out of a semi-auto barrel may be questionable...remember, some of the gas behind the bullet is being bled off in your AR. Even though it's not enough to eject and recycle, it is further reducing the muzzle velocity, assuming the bullet makes it to the muzzle.)

There are many bolt action .223's where those loads might have some utility. When you get into gas guns, however, the whole ballgame changes.

 

[steve4102]

Your AR is a "gas" gun. The gases produced by the burning powder enter the gas port in the barrel and cycle the action, it's called port pressure. The slower the powder the more gas produced. Fast powders like 2400 produce very little gas therefore very low "port pressure". 2400 will not produce enough port pressure to cycle the action of your AR, but it will produce enough chamber pressure to damage the rifle if you exceed it's limits.

What this all means is that 2400 is a bad choice for your AR if you want it to cycle. No matter the charge or the OAL you will have cycling issues. Switch to a slower powder.

 

[wingman]

Sadly sometimes we have "stuff" on hand that simply does not work well, only answer "bite the bullet" buy another powder. Remember the economy needs us purchasing.....

 

[jerkface11]

My question is: should I decrease the col to increase pressure so the rifle will cycle or should I increase the powder charge?

That would only increase chamber pressure. Port pressure would remain the same.

 

[Woody3]

Ok,

Basically this is the consensus: 2400 will not cycle because the gas pressure at the port isn't great enough.

I have two manuals that list 2400 for the .223. One is Speer and I can't remember the second one. My best guess is that the loads listed in those manuals are for a bolt action .223 and not a semi auto?

Well, it was worth a try . Guess I'll have to use the 2400 for my mag loads.

Thanks for the help guys.
Woody


Keep your head low and your powder dry.

 

[rcmodel]

2400 will not produce enough port pressure to cycle the action of your AR, but it will produce enough chamber pressure to damage the rifle if you exceed it's limits.

What he said.

Gas operated actions are very specific on what powder burn rate will work to produce the gas port pressure it was designed for.
Too fast, or too slow is bad JuJu.

rc

 

[Sport45]

One thing to keep in mind is that 14gr of 2400 (or any powder, for that matter) will only produce 14gr of gas once ignited. The rifle powders mentioned work better in a gas gun because you put more mass of it in the case and thus generate more gas for propulsion and cycling the action.

 

[rcmodel]

Not exactly.

2400 would produce enough gas, just not in the right time & place in the barrel where the gas port is located.

Slower burning rifle powder burns for a longer duration, and the expanding gas is still pressurizing the bore way out there where the hole is.

rc

 

[LiveLife]

Maybe you could trade the 2400 for another powder/reloading stuff? - http://www.thehighroad.org/forumdisplay.php?f=50

Perhaps local FTF exchange?

 

[Sport45]

Not exactly.

2400 would produce enough gas, just not in the right time & place in the barrel where the gas port is located.

Slower burning rifle powder burns for a longer duration, and the expanding gas is still pressurizing the bore way out there where the hole is.

rc

I agree. But part of the reason this works is because 26 grains of rifle powder produces almost twice the amount of gas (by weight) as 14 grains of pistol powder. The mass of the powder equals the mass of the expanding gas that drives the bullet down the barrel. The priming compound generates gas too, but it's generally insignificant compared to the powder charge. The amount of gas generated by the small charge of pistol powder has expanded too much to work the action by the time it reaches the gas port.

I don't know of any pistol powder loads that will cycle an AR. But since there are so many good rifle powders available I don't really see the need to look for one. I would think the gas port would have to be moved pretty close to the chamber to get a fast powder like that to work the action.

 

[GooseGestapo]

I attempted to do much the same thing several years ago with my AR15.

The fastest burning powder that will produce the gas volumn and pressure curve to function the AR is Acc1680. I used the slightly slower burning IMR4198. At 19.8gr I could get my rifle to function with a 50gr cast-gaschecked bullet.

Unfortunately, the velocity/pressure was too much for the bullet for functional accuracy.

I suggest that you stick with at least Acc1680 and "cheap" 55gr FMJ's for the AR....

 

[Woody3]

Thanks for the help guys. Looks like I'll try a different rifle powder.
It was fun trying to work the load up.


Keep your head low and your powder dry.