5.56 Barrel Twist and Load Data

[FUBAR63]

Hiya group, I hope everyone is well and making through this dreadful winter in good spirits. I am tired of the cold!! I have a question that I have never really been able to get the answer to, though I have scoured countless copies of load data. I have several AR's, most are 1/8 twist rate but my newest DPMS Bull is 1/9 rate. That got me to thinking about the load data ive been using. Only Nosler and Hornady have "Service Rifle" Data published. Hornadys data is for a 20" 1/9 twist rate barrel (which is exactly what the Bull 20 DPMS is) and Noslers is for a 1/10 twist. Is there a way (formula perhaps) to determine powder amounts for certain twist rates? If you look at all the load data, most are for .223 with a 1/12 twist rate so if i do follow that data, i am using starting loads. I would love to get exact with this. Any thoughts on this? Thanks men!

 

[rcmodel]

It makes no difference.

You should be using start loads and working up anyway.

From a reloading standpoint, .223 is 5.56 is .223, etc.

rc

 

[Rule3]

Not so much in powder charges but twist rate is more of what bullet weight they will handle.

This site is very helpful:

http://www.6mmbr.com/223rem.html

 

[steve4102]

No need to adjust powder charge to accommodate twist rate. As stated above, it can be important to match bullet weight/length to twist rate, but powder charge, not so much.