AR load data?

[TrxR]

Wheres a good place for AR load data?

Ive got a IBI 19" barrel chambered in .223 Wylde on the way,

I was going to try some Sierra 77smk, 8208xbr powder, ivi brass and br4 primers but am looking for some info on a good starting point for charge weight? I undestand the military brass i should start slightly lower .

Thanks

 

[FoxAlpha]

I used the same data to start my load development that was found in my Lyman 49th and the ramshot book.
My setup is similar to yours, 18" .223 wylde barrel, 77gr SMK's, ramshot Tac. No idea if the data I used was intended for a bolt or gas gun, but it all worked out the same. I don't think you need to worry about specific load data for a gasser.

 

[Brianma65]

Wheres a good place for AR load data?

Ive got a IBI 19" barrel chambered in .223 Wylde on the way,

I was going to try some Sierra 77smk, 8208xbr powder, ivi brass and br4 primers but am looking for some info on a good starting point for charge weight? I undestand the military brass i should start slightly lower .

Thanks

This work for ya

 

[bigedp51]

Wheres a good place for AR load data?

Ive got a IBI 19" barrel chambered in .223 Wylde on the way,

I was going to try some Sierra 77smk, 8208xbr powder, ivi brass and br4 primers but am looking for some info on a good starting point for charge weight? I undestand the military brass i should start slightly lower .
And again
Thanks

If you look below you will see the majority of.223/5.56 cases are at 30 plus grains of H2O. I know the U.S military requires the 5.56 cases to be made of harder brass and not thicker like older 7.62 cases.

Meaning our Lake City 5.56 cases have the same or more case capacity than commercial .223 cases.

The difference in load data you see in the manuals between the .223 and 5.56 is due to throat length and port pressure. That being said my Savage .223 bolt action has a longer throat than my two AR if rifles

Look at lines "G" and "N" and freebore diameter and length below. It was the older .223 rifles with 1in12 and 1in14 twist barrels and their shorter .0250 throats that would generate higher pressures if M885 5.56 ammo was fired in them.

Again it will be the type gas system and port pressure that effects the AR15 loading the most. My AR15 carbine has a mid length gas system with a .0500 throat and does not pound the rifle like the shorter gas systems.

Below on the left the shorter .0250 .223 throat and on the right the AR15 .0500 throat lengths. The .223 and earlier M193 5.56 cartridges were loaded to 55,000 psi but when the M885 round was introduced the military increased the chamber pressure to 57,800 psi. This is when the SAAMI interchangeability warning came out about firing 5.56 ammo in a .223 rifle. My Savage .223 rifle with a 1in9 twist has a throat length of .0566. So today nothing is written in stone with .223 and 5.56 chambers.