Home Forums Hunting & Shooting Custom Rifles & Wildcats 243, ai or no? 10 twist or 8?

Predator masters had a thread... fellow mentioned pressure spikes with 8 twist Ackley.
Seems I heard something about this 20 years ago.

8" 6 creedmoor

I like the 1-9" twist with a standard 243, but I liked the old 6MM Remington even better.

7.5 or 8 twist 243win or 6creed. Pick your bullet and then decide cartridge.

8 twist

I have run both versions and wouldn’t mess with AI again. Certainly would opt for 1-8” twist or even faster. That said, I have zero experience with the 6mm Creed and it may be the better mouse trap currently.

Forgive my inattention,
The magic of the creed is a perfect shoulder angle, and an ability to chamber mag length rounds that are super long high b/c ??

Are folks finding good brass availability?

Yes to both. I won’t be going back to 243. Have a Kimber and Barrett in 6 creedmoor and couldn’t be more happy.

In his first Gun Gack, Mule Deer says that the lab boys report the .243 has a lot of pressure issues, especially near the top end, and it gets worse when the throat starts to erode. He avoids that by staying in bounds with his loads, something I tend to do with most rounds anyway, as ranges here tend to be short. The 6 CM is thought to be a bit easier on barrels due to the sharper shoulder. I have both. The Creed is 1-7", the .243 the usual 1-10. No problem, I just organized my bullet pile and there are maybe a couple thousand, most of which will spin okay in either. Given a choice, I'd go 1-7" every time, which should spin almost anything, anywhere.

I agree on the creedmoor. 8 twist at least.

I've owned a bunch of 243s, 2 243AIs and 2 6mm creedmoors. The only way I'd not go creedmoor is if I only shot factory ammo and didn't want to use high bc bullets, then I'd go 243.

I am a fan of the 243 but probably won't do another one (right) . I would look at the Creed, the 6x47 Lapua, 6 PRS, 6 Crusader or any or the long necked versions with around a 30 degree shoulder. Better barrel life till you go above 6 Crusader and more flexibility in seating depth.

Bullets keep getting longer and longer and now there are 6mm bullets of over 120 grains. My last 6mm has a 1-8 twist and now I consider that on the slow side. Some of the more extreme bullets now require a 1 in 6 or 6.5. The 115s are iffy in a 1-8 twist, with enough velocity and altitude they can work but no guarantee. If I were to do another rifle now it would be for the 6x47 Lapua and would have a 1-7.5 twist for bullets up to 115s.

Only if your going to shoot light bullets exclusively would I go slower than 1-8. Also a lot of the talk of pressure spikes and steep curves due to twist or other factors is pure myth. Unless you have strain gauges all along your barrel how are you going to know? I do understand it is gun gack speak for finicky loads but judging pressure spikes by feel or case appearance? If you can do this then go buy a lottery ticket too.

A 8 twist Brux with 105 Amax has never failed me.

This AI has about 460 rnds thru it and shows no signs of change

The 6 Creed is basically a 6-22/250 AI...not exact but darn close

The 243 AI has more capacity. 243 AI with 8 twists will push the 105g Berger Hunting at 3350 fps with R#26 with ease and with R#23 will push the 105's at 3200 with ease.

The 6x47 Lapua will throttle along with the 105's at 2950 in a shorter case than the creed giving more latitude in the mag box.

The 243 AI with the 115's is awesome.

There is no flies on a 6 XC, either which has a very wide tune node with H4350 with 105 and 115g bullets.

Choose your poison.

Agree with Keith. I don't see it as a downside that the 6x47 only does 2950 as that seems to be a sweet spot for many of the VLD type bullets from 105-115 grains. I can push them to almost 3350 in my 6 AI but I can't find another accuracy node above 2,950 fps. Accuracy is good enough for hunting though. The slower speed will add barrel life too.

The more research and feedback, looks like there really is something to this creedmoor hysteria!
Now my mind is back and forth... 22 or 6mm

Both good. The 6mm if primarily a deer cartridge and slightly better barrel life. The 22 for targets, varmints and deer. Go slow twist on either. The real answer is get both. A 22 Creed is tempting me as I already have several 6s.

6 MM CM with a 7.5 or 8 twist - Lots of GREAT Proper Headstamped brass avail ! jmo RJ

The "creeds" pretty much made, 22-250/22-250 ai, 243/243 ai/6mm, 260/260ai obsolete, with good reason, unless a guy thinks (fireforming) is cool, which it's not......

Tejano, RAS tuner/brake, Harrell's tuner brake, Gunsandgunsmithing tuner will change a lot of your thinking on tuning loads. I promise!

Agreed Jud, that damn 22 Creed has even made the Swift obsolete..... but I will never admit that to Hig & Kingston... or the rest of the skinny jean/flatbrim crowd.. ha