223 AI velocity potential

[nrspence]

My 223AI started life as a Rem 700 LTR 223. Shortly after purchasing it I got this notion I just had to have a AI version so I dropped a basically brand new rifle off at Defensive Edge and had Shawn true the action and hang a new 22in Hart 9tw Sendero/Varmint contour barrel on it chambered in 223AI. I guess 22 must be a pretty popular length for 223AI's. First three shot group he put down the barrel went a .112 so it definitely shoots.

As for velocity expectations, you will hear alllll kinds of crazy numbers thrown around with some that I've heard as high as 400 fps over a standard 223 and always with the same story of "and that's with no pressure". The little 223 case using tough brass like Lapua and squaring off the shoulder to a 40° which takes most of the taper out of the case can take a shit ton of abuse without showing much pressure so some folks just keep pouring the coal to them then thinking they're getting mystical physics defying velocities. AI'ing a 223 case only nets about a 2gr measured in water increase over the standard 223 and you aren't going to get 3-400fps increase with that amount of gain, but, you can get that kind of gain by running the pressure up in your loads. And for what it's worth I don't care how someone loads their stuff. Run it till the primers pop, makes no difference to me.

Pressure being equal the 223AI will run around 100 +/- fps faster then the standard 223. I often hear people ask "is it worth it" and that depends on the person. If you don't mind fire forming brass and FF loads generally shoot just as well as fully formed brass, that .112 I mentioned earlier that Shawn shot with my 223AI was with a box of factory Hornady 223 53gr Vmax Superformance ammo I dropped off, and you want something a little different then the standard 223 then a 223AI very well could be for you. The AI version certainly has a certain cool factor to it and when you compare the two cases side by side the AI version definitely looks "cooler" but does that make it worth it, only you can decide.

Also, some people, depending on what type of bottom metal they use or what they use as their build platform experience feeding issues. As I mentioned my 223AI was built on a Rem 700 using a HS Prec. det mag setup and I've never experienced a single feeding issue with mine. Mine shot extremely well as a factory Remington LTR 223 but it now shoots crazy good as a 223AI but that probably has more to do with it now wearing a Hart barrel than it does being a AI version.

Last thing, don't let anyone tell you all you need to do is run a 223AI reamer in an existing 223 chambered barrel to make an AI version. All that'll do is give you excessive headspace. You can ream an existing 223 barrel to 223AI but it needs to be removed, some thread cut off, THEN, reamed.View attachment 565225

That is a legendary well thought out response right there.

 

[swavescatter]

77 TMKs
With a 22" Tikka 223 I'm getting 2870 fps (suppressed).
With a 17" Tikka/CarbonSix 223AI (with extra freebore) I'm getting almost 2800 fps (suppressed)

At 25fps/inch*5 inches, the 223AI should be getting about 2925 fps in 22" config? Or about 55 fps?

Not *quite* apples to apples since I'm using H4895 in the 223 and 8208 XBR in the 223AI. Also Starline brass in 223 and fireformed Lapua for the 223AI.