223AI in gas guns

[TonyTheTiger]

Just curious how many people have done this, what works and what doesnt. I've heard of a few out in the wild but google searches turn up countless old farts saying they haven't tried it but it definitely can't be done. Looking for more experience based info than that.

 

[Hoser]

I have two. My latest below.

As long as you don't overload the mags, they run just fine. I only put 15-16 rounds in a 20 and 25 rounds in a 30.

 

[TonyTheTiger]

No mag or feed ramp modifications needed? And did you buy them AI or have it done afterwards?

 

[Sledge1]

Ok, I gotta ask. What's with the grip?

 

[Hoser]

No mag or feed ramp modifications needed? And did you buy them AI or have it done afterwards?

No changes needed.

This one started out as a Kreiger blank.

 

[Hoser]

Ok, I gotta ask. What's with the grip?

Pink ribbon for cancer research, but in the form of a pink grip.

 

[TonyTheTiger]

No changes needed.

This one started out as a Kreiger blank.

Good to know. Whats your load data look like?

 

[K_4c]

Projectile and MV?

I'm building a .224 Grendel so I can run the 75-90 class projectiles. I don't see a problem hitting 3k with 75 eld's.

 

[Hoser]

Good to know. Whats your load data look like?

Lots of Varget under a 69 Matchking or 73 Berger using LC brass. Federal or CCI primers.

 

[TonyTheTiger]

What kind of velocities can you get out of the 73's?

 

[TonyTheTiger]

Projectile and MV?

I'm building a .224 Grendel so I can run the 75-90 class projectiles. I don't see a problem hitting 3k with 75 eld's.

I've been contemplating a Grendel variant for a couple years, but then I lookat all the 223 barrels and buckets of brass I have and it makes me think the AI would be just the ticket for a cheap ass like me.

 

[K_4c]

I got a 6.5 and 6 Grendel already... love the cartridge.

 

[Hoser]

What kind of velocities can you get out of the 73's?

2900-2950 with not a lot of pressure.

 

[seven mm]

Nice looking rifle. Barrel length?

 

[TonyTheTiger]

2900-2950 with not a lot of pressure.

Thats a little disappointing, thats what I'm getting with a 223 22" barrel with 73's and no pressure.

 

[Yondering]

Thats a little disappointing, thats what I'm getting with a 223 22" barrel with 73's and no pressure.

That's to be expected with Varget in my experience. He could use a different powder and pick up another couple hundred fps.


Side note though - the "no pressure" comment is a little odd; there's always pressure. I'm guessing you meant no pressure signs, while Hoser may have just meant mild pressure, which could also mean no pressure signs. i.e. it sounds like you're both trying to say the same thing.

 

[TonyTheTiger]

You're correct, I should've said no pressure signs visible.

 

[Hoser]

I found a real accurate load around 2950 from a 20 inch barrel so I stuck with it. When I tried to get over 3,000 I started to get some primer cratering. Over 3050 I started to get ejector swipe.

IMR8208 gave excellent velocity, but accuracy wasn't there.

 

[Yondering]

I found a real accurate load around 2950 from a 20 inch barrel so I stuck with it. When I tried to get over 3,000 I started to get some primer cratering. Over 3050 I started to get ejector swipe.

IMR8208 gave excellent velocity, but accuracy wasn't there.

Out of curiosity, do you remember what top velocity was with 8208, and what the top powder charge was?

In my load development over the years with standard 223/5.56, I've noticed a general trend in the 65-77gr bullet range: High energy ball powders like TAC, CFE223, LVR, etc give top velocity potential, 8208/Benchmark gives up 150-200 fps from that, and Varget gives up an additional 150-200 fps from 8208 or ~350 fps from TAC. That's in my barrels with my load development methods of course, so YMMV.
And of course if accuracy isn't there, the additional velocity isn't worth it, but sometimes it'll get you to a higher velocity accuracy node.


I've wondered about the AI in a gas gun too; good to know that yours feeds well.

 

[TonyTheTiger]

I got a 6.5 and 6 Grendel already... love the cartridge.

Whose barrels are you using in the variants?

 

[K_4c]

Whose barrels are you using in the variants?

JP for the 6.5

McGowen for the 6mm

ARPerformance for the .224 Grendel

 

[TonyTheTiger]

JP for the 6.5

McGowen for the 6mm

ARPerformance for the .224 Grendel

How does the McGowen shoot? Curious because they offer 223AI AR barrels.

 

[K_4c]

Real good. I've shot 105 RDF's/ hybrids, 95 smks/tmks, 85 bthp's and 75 vmax... nice m4 cuts (no feeding issues) and clean chambering.