Analysis: Velocity Comparison to Barrel Length on an AR (223/556)

[SA Friday]

This is one I did a couple years ago and had issues posting all the info. I now have the ability to convert a DOC to PDF and it seems they post here better. I'm going to repost this one in it's full form. This one isn't as refined, there was less editing and formatting on it, but the info is solid.

Enjoy.

79166

[Gman]

Interesting info. Thanks for sharing.

I'm curious as to the length of gas systems used (Carbine, Midlength, Rifle) and how they would affect velocity (if at all).

[O2HeN2]

Also see: http://www.ballisticsbytheinch.com/

O2

[SA Friday]

Also see: http://www.ballisticsbytheinch.com/

O2
Yes, but I didn't want to use their data for the analysis. They didn't chart it. The didn't use 77 SMK either.

[Tim K]

Your data on the 77's correlates to my own data quite well.

It'd be interesting to look at that bullet again and see if powders with different burn rates behave differently than Varget.

I'm no internal ballistics expert, but I'd suspect TAC (faster burning) might benefit even less from longer barrel length in the 18"-24" range? I wonder if that's true...

[SA Friday]

Your data on the 77's correlates to my own data quite well.

It'd be interesting to look at that bullet again and see if powders with different burn rates behave differently than Varget.

I'm no internal ballistics expert, but I'd suspect TAC (faster burning) might benefit even less from longer barrel length in the 18"-24" range? I wonder if that's true...
I have a TAC load that I currently use for competitions instead of Varget. I get just a touch more velocity out of it at the same accuracy. I shoot it out of 18s and 24s It's just an easier powder to reload with and that's the big sell for me.