223 Ackley Improved

Starline support is working with me thus far. I will keep updated
What’s the word from Starline so far? I don’t have the vertical fractures that you have, but that case separation midway up the body is exactly what I’m getting with 69SMKs through 88ELDMs using CFE. I’ve tried adjusting charge weights up and down during fireforming, and every time I get what I’ve started calling a “speed bump” right where the case eventually separates. I’m really interested in what they have to say.

My brass is 2 different lots of Starline that were bought within the last year or so.
 

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Loaded up some 69 TMKs with Varget for my 20 inch AR.

27.1 gns of Varget fills the case about half way up the shoulder. 69 TMK seated to mag length are going about 2950 with a single digit SD. Accuracy for a 10 shot group at 100 is just over 5/8.

Rifle length gas with an adjustable gas block and TBAC Dominus suppressor.

Note to self. When you set the OAL with a steel 20 round mag, remember to check that these will still fit in a Magpul plastic mag.
 
That’s some nice CS
Sounds like they had a known bad batch of brass (from 2021), so would've hoped they replaced it.
This is the only brass issue I've heard of from Starline, so hopefully it was a one off as I'm going to try get starline brass for my 223AI (if the barrel ever turns up....).
 
Loaded up some 69 TMKs with Varget for my 20 inch AR.

27.1 gns of Varget fills the case about half way up the shoulder. 69 TMK seated to mag length are going about 2950 with a single digit SD. Accuracy for a 10 shot group at 100 is just over 5/8.

Rifle length gas with an adjustable gas block and TBAC Dominus suppressor.

Note to self. When you set the OAL with a steel 20 round mag, remember to check that these will still fit in a Magpul plastic mag.
If you want a little more OAL, try an ASC stainless 5.56 mag.
 
One thing to note as well is that this was 5.56 Starline brass which they change the metallurgy of the bottom half a bit to make it harder. Whether that is relevant? I don't know. But I thought it worth mentioning.
 
Out of curiosity, has anyone played/experimented with or found a decent load using the Berger 85.5gn LR Hybrids in 223AI?

There is a decent availability of them local to me and was hoping there may be some experience in terms of starting loads or even optimal loads.
 
Out of curiosity, has anyone played/experimented with or found a decent load using the Berger 85.5gn LR Hybrids in 223AI?

There is a decent availability of them local to me and was hoping there may be some experience in terms of starting loads or even optimal loads.
I think the 80 Berger’s would be a better fit but I know some people run the 88 eld’s. I’m sure you could make them work.
 
Got the replacements. So far one of the twenty I have fired split in the same way as before. Gonna contact starline again for recommendations.
 

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Fellas, I finally quelled a nag I couldn't get rid of so I bought a .223 Zermatt action. My 'smith will mate it to a Mullerworks 1/7 at 26". I'm giving serious consideration to an ackley improved. Most of my shooting will be at 550 but my range does go to a 1000. If I go with the AI, my intent will be to shoot factory Lapua bullets to begin fire-forming. I understand the brass may need 2 firings to complete FF. If that is the case, how do I set up my FL sizing die (use to to just neck size?)? Thanks,
 
@YamaS3rider
I have a 24" 223 and a 22 and 26" 223AI. To me, inside of 600, the difference isn't very noticeable. The 223AI impacts on steel at 1K are definitely bigger and louder.

The smith who did my 22", cut the chamber so it uses the neck/shoulder junction on 223 brass as a false shoulder. I just load normal 223 and shoot. The 26" barrel does not have this feature, so I load the 223 rounds long to make sure the bullet touches the lands. This keeps the round against the boltface during firing.

For fireforming- I use annealed brass, typically Lake City or Lapua, and a full load of fast powder- N133 or H322. Loading after that is very accurate. My 22" gun came with a 1/4 MOA guarantee and it will do it with the once fireformed brass.

On edit: 223AI seems inherently more accurate to me. I can try different powder with larger weight spreads, and the velocity remains more stable than 223.
 
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Have you tried other brands of brass? Is it possible your chamber is oversized? I have run hundreds of starline brass forming into 223ai without issues.
This is their 5.56 brass. They say they change the metallurgy of the bottom half as compared to their 223rem brass.

Yes I have tried Lapua, Federal, PPU. All with same or greater loads. No issues.

Gonna grab a bag of Starline's 223 brass from Cabela's next time I'm there.

*Edit: Also tried Winchester and LC with no problems.
 
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