223AI with 90gr bullets?

[BoilerUP]

Hoping to get some insight...and yes, I've done many searches!

I'm planning to build a 22" 223AI in a tactical/field type rifle, primarily for paper & steel targets out to 650yd. My bullet of choice is the 80gr A-Max, and I think 2900fps is easily attainable with that barrel length. This would shoot inside a 308/175 SMK @ 2700fps.

At 500' ASL elevation and standard atmosphere, Shooter app shows a 1:8 twist (which many say shoots the 80gr A-Max well) providing a stability factor of 1.19 at 2900fps.

I was all set up to order a 1:8 twist barrel, but I went and ran the ballistics of the 90gr Berger VLD @ 2800fps and saw it provides 6" less drift at 650yds and 20" less drift at 1000yd...which got my attention. With a 1:7 twist, the stability factor for the 90gr is 1.35 and the 80gr A-Max runs 1.56.

I guess my questions for those much more experienced here is this: are these velocities realistic for a 223AI? Should I go with a 7 twist and try 90s, or are they finicky enough that I should stick with an 8 twist and run the 80s?

Thanks!

 

[fivering]

What barrel length?

With a short (<25" barrel, it is not a slam dunk to get 2900 fps.

 

[40X Guy]

In my .223AI with a 28 inch Brux 8 twist barrel, I am getting 2,980 fps with a 75 A-Max bullet. After testing 4 different powders that did not achieve the results I was looking for, I used IMR 8208XBR and shot an OCW test and came up with 24.5 grains, mild but shoots real good. With a short barrel/tactical setup, I would probably opt for an 8 twist barrel and set it up for 75-80 grain bullets. The 90's are a whole different world and would need a long barrel to get the results wanted. Plus powder charges as i have discovered have to be all 100% equal in this case and finicky they can be!

I believe forum member "Froggy one" is shooting 90's but in a standard .223 case. He has a lot of insight to offer on the .223 family and will probably chime in when he sees this.

Frank

 

[bozo699]

In my .223AI with a 28 inch Brux 8 twist barrel, I am getting 2,980 fps with a 75 A-Max bullet. After testing 4 different powders that did not achieve the results I was looking for, I used IMR 8208XBR and shot an OCW test and came up with 24.5 grains, mild but shoots real good. With a short barrel/tactical setup, I would probably opt for an 8 twist barrel and set it up for 75-80 grain bullets. The 90's are a whole different world and would need a long barrel to get the results wanted. Plus powder charges as i have discovered have to be all 100% equal in this case and finicky they can be!

I believe forum member "Froggy one" is shooting 90's but in a standard .223 case. He has a lot of insight to offer on the .223 family and will probably chime in when he sees this.

Frank

Frank is correct,..FroggyOne2 has been shooting the 75 v-max and the 90 grain burgers out to 1K with a .223, and doing real well with them in his matches, give Randy a p.m he is a very nice and helpful guy.
Wayne.

 

[Bradley Walker]

The best .223 I ever shot was the Kreiger 1-7.7.

 

[BoilerUP]

Okay, I've ordered my barrel: a 22" 7 twist Criterion (Savage prefit) in 223AI. Criterion's 223AI reamer has 0.061" freebore.

Based on my other thread, I've established the 75gr A-Max should touch the lands at 2.504" COAL in my chamber.

I've read some posts by Laurie saying his 223 chamber has "about a quarter inch of freebore" and the Berger 90gr VLD was about 2.685" OAL to the lands. By my math, that should put the 90gr VLD to an OAL of 2.496".

Assuming that OAL to the lands, the 90VLD having a length of 1.263" and 223 brass at a 1.75" trim length...I think 0.517" of the bullet would be in the case. That'd obviously eat into powder capacity, but I'm wondering if the AI could get it up to ~2800fps...

 

[cb1229]

We achieved 2850fps with reloader15 and90gr burger vld magnum primers not sure on powder we used the same load that Laurie Holland used in 1k f class he did an extensive articals in target shooter mag in 2010 to 2011 for load data they are in there archives check it out lots of good date to support the load info he also and we also used a 1/7 twist he set a group record with his load also I think it was group size.

 

[flatlander]

I got around 2800fps with RL15 & some old JLK 90VLDs out of my 1:7tw 26" 223AI - these were fireform loads using some old leftover 90 ammo from Service Rifle days. Judging by a few cases with faint ejector swipes on caseheads, I'm thinking 2800 may be about max with 90 VLDs & RL15 in this bbl. If I want more vel, I'll have to go with N550, which has always been the top powder for use with 90s in my 223s.

Based on this, I think you'd probably have to have a particularly 'fast' bbl. to get 2800 out of 22", with anything other than N550.

 

[FroggyOne2]

I am currently using Lapua brass that weigh in the 93.00 - 93.99 gr range. My current seating depth from base to ogive is 2.032. This is with the Berger 90 grain VLD, the load that I am using is 25.0 grs of RL15. At this dept, the base of the bullet is just at the shoulder and body joint of the case. I am just about out of my supply of Wolf SRM primers and have switch over to the Tula boxed version. Actually the Tula boxed version fit tighter in the primer pocket. The bbl is a Rock Creek 5 groove 7.2 twist that is 30 inches long. Velocity is around 2850 fps (have not actually chronied it). To get the 90's to shoot your load process is very critical, esp in the brass prep. Running a short bbl even with the AI version and the 90's is going to be real trick in a tactical rifle. Those 90's don't feed very well sticking way out like they do. In my Barnard, I have to actually put the round in the chamber, just laying it in the loading port and closing the bolt don't work. Remember that in a tactical version, it has to feed reliablely and with the limitation of the lenght of the magazine the 90's would not work and I doubt the 80 Amax would either, that bullet is kindaa long too!

 

[BoilerUP]

Bumping this one from the dead...

I finally ended up trying the Berger 90gr VLD in my 22" 1:7 223AI with 0.061" freebore a couple months back.

24.9gr Varget in a fireformed Nosler case with CCI-450 approx. 0.005" off the lands gave me 2750fps, which was confirmed on steel at 650 yards. I need to fine-tune seating depth (and probably need a VLD Micrometer for my Redding Competition seater) but I've been quite happy with their performance thus far.

They don't really gain much over my 80gr A-Max @ 2950fps load at 650yd, but start to walk it beyond that.

 

[cmillard]

I use nothing but Lake City brass now a days in my .223 long range ar-15. after prep, I sort by weight. my prep includes everything from primer pocket uniforming, flashhole deburring, trimming, and neck trimming. I then resize after all prep with forster fl die and bump shoulders .003. I separate into 1 grain increments. I have found LC brass to be very tough and can hold much more powder than other brands of brass. I am shooting a 1-7" compass lake (douglas blank) with match chamber and is finished at 18". I shoot 77 grain bergers with wolf srm primers and aa2520 powder. it hammers out to 891 yards (furthest I have shot with it). just remember, as Laurie Holland will attest to as well, small variance in powder charge will change impact at long range--maybe not as noticeable at 600 yards but it will be more noticeable at longer range--and after reading all his articles/posts--he shoots way out there with the .223--and you are shooting the .223 AI. I am glad you went with the faster twist--it gives you the ability to shoot the long, heavy bullets as well as some of the lighter ones in 70-82 grain class.

 

[mac86951]

I've heard that some need to extend the freebore for the 90gr bullets, If this is the case, do you sacrifice the 75-80gr accuracy?

for 650y, the 80gr should be sufficient. I'm shooting the 77 at 2.260" at 600y.


-Mac