243 vs 243AI...

cdatdog

New member
Okay, those of us who have the Plain Jane 243. And those that have a 243AI. Who's happier? With the cost to re-barrel, fire form your cases, just to gain maybe a 100' FPS. Is it really worth the cost? For all the invested monies to have an AI. Wouldn't it be easier just to get another "Plain Jane" in 22-250...
 
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Forget the 243 AI go with the 6x284. Mine is a screamer 70gr Nosler BT 4,000 + with Re#17. Much easier cartridge to load for no fire forming. Just buy Norma 6.5x284 brass and run them through a 6mm x284 FL die and your ready to shoot.
 
I went to the .243AI and will never look back. Brass stability is on of the big plus's over the .243win. With Reloader 17 I run 70gr Sierra Blitzkings at 3850fps (and I'm quite sure I could get 4000fps if I wanted), 87gr v-max's at 3600fps and 105 Berger VLDs at 3350fps.
 
Originally Posted By: cdatdogOkay, those of us who have the Plain Jane 243. And those that have a 243AI. Who's happier? With the cost to re-barrel, fire form your cases, just to gain maybe a 100' FPS. Is it really worth the cost? For all the invested monies to have an AI. Wouldn't it be easier just to get another "Plain Jane" in 22-250...

I think it all depends on how much velocity you want in a 6mm rifle. The 22-250 is fine, it's just not a 6mm. It's good to own a 22-250, but let's talk 6mm which you asked about.
The two guys who posted here have the two VERY best 6mm's for velocity.
If I were you, looking strictly at 6mm's, I search the ballistics of both cartridges mentioned, and make your own decision.
I have a standard 284 and LOVE that case. I compared ballistics of the standard 280 Rem, and the 284, and decided on the 284 because of it's short, fat case, compared to the long 30-06 case necked down to make the 280 Rem.
 
It all depends what you are using this rifle/caliber for?

If you have a 243 already you don't need to rebarrel, just run a reamer in and headspace. To fireform to 243AI just shoot 243 factory ammo!

I have had both, a 243AI and a 6/284. The 243AI is inherently accurate and 6/284 is touchy to load for accuracy. The 6/284 needs more powder to achieve the same velocity in the 243AI.
 
The 243 AI is a great round. The 243 Lapua brass is second to none ! Easily 10 -12 loadings out of it.

The ackley version basically eliminates case stretch.

Fireforming is easy, can always shoot factory ammo thru it. Not to mention fireform loads are incredibly accurate as well.

Go with a faster twist barrel, ie. 1 in 7.5 is ideal for the heavies, gives you the ability to shoot the bigger, better BC bullets. 105 to 115's are where it is at ! Less than 20 MOA at 1000 yards.

Now, throw in the 6mm Crusader and you have a bigger gain over the 243AI, but not the great Lapua brass !

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1014170#Post1014170

My vote is for the 243AI... easy to load, great brass, accurate, easy to fireform, etc, etc.
 
It's worth doing. The .243 case has very little taper anyway and is already semi-improved, but the shoulder blows forward quite a bit and you'll get more than another 100fps. My first .243 was a Rem. varmint special.....the load was Win760 powder and 60 Sierras at 3800. In the .243AI, accuracy load is with 760 powder and a 70gr bullet @ 3850 - 60's@4085 - through a 25" barrel. There's NO "fireforming" involved, just find an accurate load as with any other cartridge and go use it. The "fireform" accuracy load will be just as accurate and considerably faster than a std. 243. Your load with formed brass will be very nearly the same. If you want to go 4000+ with a 6mm, the 6mmRem case has a lot more taper.......the 6mmAI blows out considerably and accuracy loads with a 70 can do 4100.
 
I have always loved the 243 Win. I think it works right well as is, although I hate trimming brass. I may rebarrel my 243 to 243AI when I burn it out......
 
243 AI is a wonderful cartridge, fits a short action also.
With a longer barrel, you will be chomping on 3850 with the 70's using Win 760 and a CCI 250 Primer. I uped the powder charge 1.0g and changed the primer to a Win Mag primer and the velocity was 4030 fps. Key to my rifle is a 1-12 twist.
If you go to a 1-8, there is a pressure spike that changes everything.

I had the 6/284 and the 25/284. The 6/284 is a strong case. It will shoot the 80's about the same speed as the 243 AI does with the 70's. There is a HUGE down side to the 284 case on a short action, and that is only if you use the magazine. A pointy bullet(vld) will not go in the magazine when touching the lands with this cartridge when you seat the bullet out to engage the lands. I had to have a slot milled in the side of the ejection port to exract the loaded round without removing the bolt. These two cases should be put on a long action.

Also, the 244 AI is just as good as the 6/284 if not better. I got 4150 out of the 70's in a 1-14 Shilen 26" long and 3800 out of the Sierra 80g BT Blitz bullet, one hole accuracy out of both. This is another cartridge better served on a long action.

If you are speaking about rechambering an existing barrel, I would consider it a waste of money unless you have a 26" varmint weight barrel.

Just my 2 Cents
 
I don't feel slighted running DTACs from my straight up, GAP match chambered .243 in a 1:7.5" twisted Rock...

Different strokes for different folks...
 
If a guy is going to go through and re-barrel a rifle, the advantages of that alone is worth it in accuracy over a factory barrel, why not have it re-chambered for the Ackley at the same time???....Faster, better on brass and I have been told it is inherintly a more accurate cartridge? I love my AI but most of the "love" is in the extreme accuracy from the Hart barrel, I'm sure the standard .243 would also be very accurate in this barrel. Brent
 
Originally Posted By: justin10mmWouldn't fireforming every case reduce overall barrel life?

You can use the corn meal technique so you aren't using barrel life.
 
Originally Posted By: justin10mmWouldn't fireforming every case reduce overall barrel life?

You're unclear on this. Go back and read what's been said. Loads that "fireform" are accurate fast working loads that also result in a formed case.
 
Yes, but when fireforming loads you don't get the added velocity of a finished case. You don't see the gain in performance until the second firing.

Never heard of the corn meal technique.

I've heard of people having a second rifle cut with the same chamber reamer as their main rifle. That way they use one rifle solely for fireforming and shoot only finished cartridges in the other. Dose that make sense?
 
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