Home Forums Hunting & Shooting AR and Tactical Rifles 223 Ackley in AR?

The 4 to 1 rule applies. If you wanted to gain 125 fps over the 223, you'd need around 16% more case capacity. I've had several 223 AIs to go along 223s, and never have seen anywhere close to 125 fps increase.

That is exactly correct

Jeff; That is exactly correct which is why John increases the gas tube length (and properly ports) his longer barreled match riles... I picked brass at Perry from the AMU team in 2001. They had the Black Hills V8 load with 80s and VV135..Believe it was near 2900 fps in a std service rifle 20" bbl..Brass was [bleep] but shot well You can easily do this with a match rifle with a bit longer barrel set up properly and the AI makes it foolproof.

Or so I thought...You guys are missing the boat on a properly set up AR regardless of the chamber..

Who the hell pounded that sand up your a$$?

IMHO there is no reason you can't hit 60kpsi in an AR and the 5.56/223 round. And never have a worry in the world. Why they hold it back some is beyond me. But I digress.

The AI is so simple, and nets you a gain for almost nothing in cost, why not? Can give you a bit of an edge in a match and at less pressure just depending...

I have not known John to ever not have his head totally wrapped around a complete package!

Jeff

How the hell could someone post on this site for 14 years and not have heard of "The Rules"?

Cartridges aren't magic, as much as some guys want them to be.

That v8 load was way too hot. 1 shot, trashed brass.

Depends on what brass was used... I"ve seen new brass trashed by one load that probably didn't even hit 52kpsi...

Big Green uses factory primed new LC.

If thats the case, then its a pretty warm load for sure. FC brass OTOH I would have to back off more than a full grain to be safe from my LC cased loads.

Agree, several here have said it and know it but you can't change the mind of those that want to believe something else. They try to compare a high pressure AI load to a factory 223 or 5.56 load.

And the case change is what allows you to run higher pressure.

As I've said on my bolt gun, a littler Kimber Montana I had the barrel set back and AI'd, I got 3570 fps with a 55 grain Nosler Ballistic Tip in that 22" barrel. Primers are not even close to flat, no tight bolt handles and primer pockets are tight after several loadings. Pressure equals velocity but you have to be able to handle that pressure and the improved case is magic in that regard.

On the other hand I've seen 2 grains of powder make more than 50 fps difference by itself.

It doesn't work that way. Changing the shoulder shape and straightening the body does not allow you to run higher pressure. You could've run that same pressure in a standard 223 case as well.

I'm guessing most 223 AI reamers cut a longer throat though, more like 223 Wylde? That accounts for a lot more potential velocity difference than the minimal change in case capacity. Similar to comparing 223 Rem and 5.56 loads.

Show me I'm wrong don't guess. Load up 3570 in a standard 223 and 22" barrel to see how many reloads you get.

A few notes now that I have a minute, it has to do with less bolt thrust on the straighter case and all my bullets are seated in the lands.

The gains are real.

I believe the gains are real, just not your explanation of the reason behind it. Case shape does not change the bolt thrust; that's made up by people who don't understand how pressure works. If the case body sticking to the chamber walls really reduced bolt thrust, you'd have a much higher chance of case head separations with an AI chamber. It doesn't work that way.

Like I said, the difference in the throat does a lot more to account for any significant gains.

I've got a several standard .223's and .223 AI's. I'll grab a .223AI nearly every time for its 100-150 + velocity difference. I frankly don't care where the extra velocity comes from; vudoo, physics, magic, pressure, whatever. Maybe its just that the 223 AI accuracy nodes always seem to be near or at max pressure, while my Standard .223's seem to shoot better a step down from max. As an example, I have a .223AI with 24" barrel that hammers 75g Amax's at 2950. Compare that to my Standard .223 McMillan Sporter with 24" barrel that won't shoot a 75g Amax or Berger accurately past 2750 and really tightens up at 2650 fps. Anecdotal for sure, but its my reality.

To each his own.