New Build - 223 vs 223AI

[Oso]

I am starting a new build in the 223 family. The gun is a trainer and will be used to shoot mostly paper and some steel mostly mid-range, but on occasions stretching it out the 1,000 yards. The hardware for the gun is Rem 700 action, Brux M24 1:7 twist at 24", Jewell trigger, AIC 2.0 chassis stock. So all of the components should be solid and Roberts Precision Rifles will be handling the gunsmithing. The projectile of choice is the Berger 82Gr bullet. I have plenty of LC and Lapua brass available.

I have Two (2) Issues:

1. What to Chamber - 223 or 223AI???
I know that people are running the 82gr out of 223 out to 1,000 yards. Flirting with the extra case volume for added velocity (surety) as well as making room for a big round in small case to alleviate compressing the load
Pros: Extra case capacity + 2.5 gr (translates into +100-150 fps)
More stable brass (reduce frequency of case trimming)
Fire forming is easy process
Cons: Potential magazine feed issues due to the abrupt shoulder as compared to tapered shoulder of 223 (any truth to this?)
New set of dies

2. Fluting Barrel - Weight Reduction vs POI Shift???
Yes - probably could have gone with more tapered profile, but here we are. The .224 bore is relatively small in comparison to the M24 barrel profile. I plan to hang a ThunderBeast suppressor off the end.
Pros: Reduce weight of heavy barrel compared to relatively light caliber
6 grooves would look good on a barrel with relatively long life
Cons: Potential for POI shift or reduction in accuracy
Throwing money down cosmetic hole especially if accuracy is adversely impacted

Any insight and personal experience on the cartridge would be appreciated

Thanks!

 

[patrol120]

After having my CZ reamed to AI, I really dont see a reason not to AI...you dont lose anything, and the gains are measurable.

 

[HodgdonExtreme]

Great cartridge that provides the little bit of extra horsepower the 223 can really use to launch the 75+ bullets.

A fine choice.

 

[shoot4fun]

I have a 26" 223 and a 28.5" 223AI and both are 1 in 8 twist. My 1000 yard load for 223 is a goodly dose of AA1680 pushing the Berger 80 VLD with Fed match primers. It gives me 2980 FPS.
With the shorter 223AI I can get just over 3000 FPS from a 77SMK. The load is a very healthy dose of AA1680 and CCI primer. The firing pin was bushed and a M16 style extractor installed. I use WW brass for that load. I did it just to see if I could and I worked up to it very slowly. I would not shoot it again ever because it was a one shot brass life load.
All that said, if I were doing a trainer I would go straight 223.

 

[bkw1911]

Definitely ai if running the heavies. I never had feeding issues out of the 10rd aics mags. Easily stretched to 1000. I had a mullerworks #5 and it never got too hot even with 15 shot strings. I pushed the 80gr a max out of a 22" with varget right at 2900.

Sent from my SCH-I605 using Tapatalk

 

[BoilerUP]

Ackley...

I have a 22" 1:7 with a shorter-than-optimal-for-heavies freebore and run 80gr A-Max @ 2950 with 8208XBR, 90gr VLD @ 2750 with Varget.

 

[Cinch]

8 twist Ackley and skip the flutes...you won't loose enough weight to notice...

 

[223ai]

Aaron Roberts built my original 223 on a 6.5 twist brux, and then re-barreled it to 223ai on a brux 7 twist when I got 5k rounds on the original 223 barrel. You definitely picked a great gunsmith, and I am proud to shoot for AND with him. His work is excellent.

I get 100 fps gain by going 223ai. My 223 sent 82 bergers at 2900-2910 at 26", my 223ai sends 82 bergers at 3010 at 24". For me, it was worth it because I want to try and match my 6.5x47/123 smk match gun in elevation...and come damn close in the wind. But the cases are harder to fit in a mag, you have to deal with fireforming - which sucks when you want 500 pieces of formed brass - you have to deal with picky feeding unless it is mag fed, and in my case the 223 proved to be slightly more accurate...though I am easily under 1/2moa with the 223ai. I used dot drills and barricade practice to form brass.

Pick your poison and roll with it. Knowing what I know now, I'd likely stick with standard 223. 223/223ai is my favorite thing to shoot. It's fun to put rounds on steel at 1000 while smoking all things 308. It's even more fun watching non-believers start to "get it". Good choice on the gunsmith, no matter what you end up with.

 

[Red_SC]

What throat are you all running? Naturally I want everything- I have a bunch of 50gr vmaxes for positional practice but want to be able to run 75's or 80's too.

This is tempting since I'm just setting back a factory barrel, and it's cheap and in stock.

http://www.midwayusa.com/product/40...-remington-ackley-improved-40-degree-shoulder

 

[HodgdonExtreme]

What throat are you all running? Naturally I want everything- I have a bunch of 50gr vmaxes for positional practice but want to be able to run 75's or 80's too.

This is tempting since I'm just setting back a factory barrel, and it's cheap and in stock.

PTG Solid Pilot Chamber Finish Reamer 223 Remington Ackley Improved

I'd bet Manson has a 223ai reamer on the shelf. Even if not, pony up the extra for a quality live pilot reamer.

 

[Red_SC]

The wait time is more of an issue than the cost. I'll give Manson a call, I've only dealt with JGS and PT&G so far.

Do you happen to know the freebore on yours?

 

[steve123]

I'd stick with 223 for mostly mid range shooting and get out a rifle in a bigger cartridge for the long range stuff.

 

[HodgdonExtreme]

The wait time is more of an issue than the cost. I'll give Manson a call, I've only dealt with JGS and PT&G so far.

Do you happen to know the freebore on yours?

Sorry, no... I like to get zero free bore reamers and throat solely with a throating reamer.

 

[hollowoutadime]

Another option is a 22-250 or .220, 50% more powder than a .223. I have a thunderbeast 30BA on my .220 swift, minimal POI shift.

 

[HodgdonExtreme]

Another option is a 22-250 or .220, 50% more powder than a .223. I have a thunderbeast 30BA on my .220 swift, minimal POI shift.

Or maybe a 50 cal. Those have 10 times the powder of the 223. Way more kinetic, too...if you know what I mean.

 

[hollowoutadime]

.50 cal, ha, got a few of those. The 22-250 and .220, 223 and .223 AI all shoot a .224 cal pill., the .223 and AI version use 25-29gr of powder for a 55 grain projectile, the 22-250 and 220 use around 37-38grains with the same projectile. Norma or Lapua brass improved terminal performance.

 

[Kubitza123]

I wouldn't waste time on a AI myself, if your running a 24" barrel a standard 223 will reach 2900-3000 with 25.8-26gr of varget in the 223 rifle I owned with a 24" barrel. That was on a stiller action and 24" mtu barrel. It was shooting 2985 with 25.8gr and 80gr Berger target Vld.

I now have a 16.5" barrel on a Surgeon with a Mtu in 223 shooting 80gr Bergers at 2840fps .

Personally I don't see very little if any gain unless your build turns out any different than mine.
Yes it's a compressed load but mine shoots one hole groups at 100yrds all day and I know out to 400yrds if I do my job it will print 1/4"-1/2" groups as well.

FLUTE? Yes I would if you want to lose weight, I had mine done by Kampfeld and trust me on a 24" he can take off alot of weight. You must ask him for a deeper wider flute. I can provide you pics of mine and assure you it removed a ton of weight and mine was only 16.5" barrel.

 

[BoilerUP]

My 223AI has 0.061" freebore, which I believe was a tweener to allow 40/50s as well as 80s. If I were specing out a build specifically for 80s in an AICS magazine, I'd probably go 0.077.

I dunno how some folks are getting 26ish grains of Varget into a 223 case with an 80 and not getting pressure, even if you are seating it out into the 2.5+ range...

 

[HodgdonExtreme]

.50 cal, ha, got a few of those. The 22-250 and .220, 223 and .223 AI all shoot a .224 cal pill., the .223 and AI version use 25-29gr of powder for a 55 grain projectile, the 22-250 and 220 use around 37-38grains with the same projectile. Norma or Lapua brass improved terminal performance.

What thread are you reading and responding to?

This one is about precision rifle "trainer" cartridges, which see lots and lots of rounds.

Maybe I'm tripping, but I'm pretty sure the OP has zero interest in a giant case capacity increase, and its corresponding hit to barrel life.

 

[JBRC]

223, since it is a training rifle I would keep it simple, but I would consider shooting the 90gr Bergers since you have a 7 twist barrel.

I have a 223 setup to shoot the 80gr Berger VLDs, (26", 7.7 twist, .155 Freebore, 2.520 OAL). If I built it again I would definitely take advantage of the 90gr Berger.

I wouldn't flute just go with a lighter contour, like a med palma?

 

[Red_SC]

My 223AI has 0.061" freebore, which I believe was a tweener to allow 40/50s as well as 80s. If I were specing out a build specifically for 80s in an AICS magazine, I'd probably go 0.077.

Thanks, the .060 range seems popular but I wasn't sure how it would handle longer bullets. I think I'll look for something similar.

 

[SporterII]

24" 8 twist Broughton 223 with the 75 Amax at 2.44"25.1 Varget nets 2900 and on a warm day here it gets 1000yds. I tend to agree with the KISS and move up in gun past the limits of my favorite, 223. I considered a AI. Good option for a one gun I think.

 

[Oso]

Thank you for the insight and personal experiences with your own builds. I am going to pass on the fluting (Brux voids warranty on barrels fluted by anyone but them), and instead I will apply the funds toward a stamp tax. I already have a larger caliber setup that covers distance. The motivation for this build was to do a fun trainer that could also be used by a second shooter (family member) that would be something more their size. A fellow shooter I respect had a simple approach, which was if you are building a trainer then why wouldn't you also make it capable of going out to 1000k. I realize at that distance the bullet is running on fumes and flirting with transonic.

The primary debate between 223 and 223AI was my concern of compressed loads that might result from heavy powder loads (relative to case size) in order to propel a heavy bullet at 2900-3000fps. My thought was that the 223AI would give me some additional room to seat long projectile inside case without compressing powder as much as would occurs in standard 223 case. Based on feedback it appears that 223 case volume is adequate to handle the powder volume, and although most likely a compressed load it is within case tolerances. Honestly, I could go either way... both look good and good recommendations for each. I may have to let Gunsmith toss the quarter on this one.

Edward