.223 40gr Vmax load development (pic heavy)

[z0mbies fear me]

Finally getting around to working up some loads for my 20" ar. I built this one with the light rounds in mind. (20" 1 in 12" twist barrel)


Last night I loaded up some ladder loads using Hornady 40 grain VMAX bullets and some CFE-223 powder.



Started out at 27.5 grains of powder and went up in .2 grain increments. Now this wasn't exactly precise, I was using my Hornady powder measure/scale that has an error margin of +-.1gr.



Made it to the range this morning and set up my Chrony at 10' from the muzzle as per the instructions.



I fired 10 rounds of each load across the chrono, two rounds at a steel plate at 200 yards and then a 8 shot group at 50 yards. Each group was fired while sitting with a rest under the front of the rifle and the stock against my shoulder. No optics on the rifle just yet so just used magpul flip-ups.

Anyway, my best group came from a load using 28.1gr. My average velocity with said load was 3160.07 fps (10 feet from muzzle) with an extreme spread of 203.71fps. I figure that is probably due to the +-.1gr of the powder measure. Next I'll load up some at 28.0gr, 28.1gr and, 28.2gr using my balance beam scale to fine tune the load. The 8 shot group measured 0.750 center to center.



I was pleasantly surprised with the accuracy of this rifle and load combination.

[z0mbies fear me]

Link to rifle build specs if interested :

http://www.tngunowners.com/forums/topic/86353-finally-cmttgo-build/?fromsearch=1

[Caster]

Slow twist .223 barrels rock!

Good work.

[z0mbies fear me]

Thanks! I just wanted to try something different than what most people were building. I'm happy that I did :)

[Caster]

You could try some really really light stuff with decent results. That barrel would shoot 30-35 grain stuff quite well......at smoking speeds too.