243AI

[Jbotto]

I really do love the .243. But I’ve never done much with it besides load development and sighting it in. Always been a rifle that gets used as a loaner, first my brother took ownership of it for a few years and now my wife shoots it. Maybe I’ll use it this year if I get a pronghorn tag.

Sorry to pull away from the point of this thread. I say go for the .243 AI!

 

[ImBillT]

It won’t beat a 243Win by enough to matter.

 

[std7mag]

Is there much difference between a .243 AI and a 6 Creedmore?

But don’t let practicality stop you, I say .243 AI or bust!

Same answer for 260 Rem vs 6.5 Manbun.
In a bolt rifle where you can seat the bullet further out the 260 Rem ( in this case the 243 Win) will hold about 1-1.5gr more powder than the Manbun.
Make it an "AI" and the difference is even greater. (P O Ackley never did any work with the 308 family of cases, so the technically correct terminology for them is "Improved 40°" )

Realistically though having had a 7mm-08AI, the velocity improvement isn't that great.
They do start conversations, and look cool at band camp though!!

 

[Steve O]

The funny thing about this thread is everyone who has answered did not answer because their answer to his very first question was “no”.

I’ve not had a 243AI DS but have often thought it would be a fun project. Good luck with it.

 

[BackofBeyond]

The funny thing about this thread is everyone who has answered did not answer because their answer to his very first question was “no”.

I’ve not had a 243AI DS but have often thought it would be a fun project. Good luck with it.

Well ya. Welcome to Hunt Talk.

 

[brockel]

The funny thing about this thread is everyone who has answered did not answer because their answer to his very first question was “no”.

I’ve not had a 243AI DS but have often thought it would be a fun project. Good luck with it.

Sorry. Yes I’ve had one. No I wouldn’t do it again. You are talking 50-100fps gain going the ackley route on the 243. The reason you see the crazy velocities with it compared to the 243 is the ackley design likes to hide your normal pressure signs. The only true benefit on the ackley design I see is less case stretch. Now your more tapered cases like the 22-250 or your Mauser cases there’s some gain there

 

[ImBillT]

Sorry. Yes I’ve had one. No I wouldn’t do it again. You are talking 50-100fps gain going the ackley route on the 243. The reason you see the crazy velocities with it compared to the 243 is the ackley design likes to hide your normal pressure signs. The only true benefit on the ackley design I see is less case stretch. Now your more tapered cases like the 22-250 or your Mauser cases there’s some gain there

There’s decent gain in the 280AI and 30-06AI also. The 30-06 has more body taper than the 308Win. Combined with being longer, there is substantially more increase in case capacity by improving the 30-06 case than the 308Win case. No 30-06 based AI’s don’t gain as much capacity as 250 Savage or Mauser based AI’s but they still gain a decent bit.

The 25-06 already holds so much powder for a .257” bore that it gains very little velocity by improving it in spite of the increased capacity.

Ackley himself referred to the 243Win as “already an improved case”. I guess he was referring to the decreased body taper and short neck. Obviously the shoulder was not sharp. Either way, 308Win base cases don’t have much room for improvement, and a 6mm doesn’t gain much from increasing capacity beyond a 243Win anyway.

 

[MT_Chad]

a self build in 6mm remington with a 1 in 8 twist, nice long neck on them, be a screamer with an 85 gr hammer
the most impressive deer kill that ive ever seen, considering that it was a 75 gr hollow point on a large red stag was that the guy hit it in the paunch and killed it stone dead on the spot. on the kill we found that the projectile had opened a dinner plate size hole, this was back in 1967 and has stayed in my memory as if yesterday.

I built a 6mm Rem AI with an 8 twist barrel. I'm still working on load development, but I got 95 gr Barnes lrx up to 3300 fps before bolt lift was getting heavy. I need to shoot groups now, the ammo I have loaded will be around 3150.
OP, if you don't have the rifle or a donor action yet, might consider the 6mm Rem. An intermediate or long action are great for the 6mm with those long, heavy bullets.

 

[Elkmagnet]

( in this case the 243 Win) will hold about 1-1.5gr more powder than the Manbun.
Make it an "AI" and the difference is even greater.

If you are referring to 6mm creedmoor vs 243 setup to 500yds. I was under the impression that with a 105-115gr bullet the cm would have more powder capacity and you could seat the bullets to be used in a clip.
That is unless you throated the 243 way out of spec and single feed.

 

[mtmuley]

If you are referring to 6mm creedmoor vs 243 setup to 500yds. I was under the impression that with a 105-115gr bullet the cm would have more powder capacity and you could seat the bullets to be used in a clip.
That is unless you throated the 243 way out of spec and single feed.

It's not a clip it's a magazine. And HT members never shoot over 300 yards regardless of cartridge. Ask them. mtmuley

 

[Elkmagnet]

It's not a clip it's a magazine. And HT members never shoot over 300 yards regardless of cartridge. Ask them. mtmuley

Y'all don't top load your creedmoor with a stripper clip?

 

[Elkmagnet]

I'll answer my own question.
They are the same.

 

[mtmuley]

I need to get some clips. mtmuley

 

[Wind Gypsy]

If you are referring to 6mm creedmoor vs 243 setup to 500yds. I was under the impression that with a 105-115gr bullet the cm would have more powder capacity and you could seat the bullets to be used in a clip.
That is unless you throated the 243 way out of spec and single feed.

Notice the COAL on the 243 data, could seat the bullets quite a bit longer than 2.710” COAL in most modern magazines and then the 243 would have more useable capacity. I don’t know where the bullets would start to Jam though.

The two do the same thing but I do like the creedmoor case design better, that they come standard with 8 or faster twist, and the fact that there’s more factory ammo with long slippery bullets available.

 

[DamascusSteel]

Also for the .243 ai there isn't factory ammo that i know of, right now I'm looking at a Shilen barrel with a 1-8 twist, I need to do more research on that though.

 

[brockel]

It's not a clip it's a magazine. And HT members never shoot over 300 yards regardless of cartridge. Ask them. mtmuley

At 301 things go haywire

 

[cahunter805]

I had a 243AI and sold the barrel and went back to 243Win. Wasn’t worth the fireforming hassle to me.
I setup my 243win with a longer throat setup for VLD style bullets and was getting just as much speed as I was with the AI.
Pushing 105VLDs at 3060 and 88gr hammers at 3380.

 

[Elkmagnet]

The two do the same thing but I do like the creedmoor case design better, that they come standard with 8 or faster twist, and the fact that there’s more factory ammo with long slippery bullets avavailable.

After buying one I do also. I can seat my 6mm with 105's to 2.95" and not be jaming them. But why when I can buy them loaded to 2.8" in factory ammo that shoots bug holes for $28 a box.
If you had a custom 243 with the throat and twist specifications of a factory 6mm creedmoor and hand loaded 108 eldm's puncing paper at 800yds people would drool. But buy it in a factory gun with factory ammo and your a creedbro.
If shooting 75gr and under bullets than buy the 243 win. Over 75gr I personally can't see why someone wouldn't buy a 6cm unless they didn't want the guns it was chambered in.
That's a very valid reason to go custom.

 

[shootbrownelk]

If building, I would do the 6mm Creedmoor. I’ve had a .243 and a Creedmoor. Creedmoor seems to be easier on brass and is just as readily available now.

I don't have enough hair for the required Manbun.

 

[Addicting]

This is perfect, the 6.5 requires a man bun the 6 mm requires varying stages of baldness. It’s right up my alley.

Lol