i have a tikka 243 that I've been using for antelope and mule deer when I got a tag. I was thinking of getting a little more punch out of it. do you get that much more energy and fps out of a 243 Ackley and is it pretty accurate. the dies run about one fifty at rcbs. I use 95 grn nosler bal tip
thanks

You will gain about 75 to 125 fps over a standard 243, depending on which powder and how hard you push it. I've seen many 260 AI rounds, and you will gain about 75-90 fps. Since the 243 is a little faster, you will gain maybe a little more. IMO, it's not worth the extra effort. No animal is going to know your bullet was going that much faster than a standard 243 Win. Work on learning how to shoot your rifle as is and good shot placement, and the rest will work itself out.

What Chad said, but I would add that if you want more, just step up to a .25-06. You can't make one out of your .243, of course (different actions, long vs. short) but the performance may be more what you're looking for. Good luck.

(I know....this isn't what you asked, just throwing options out there)

What Chad said, the real advantage of AI in the 308 family of cases is the cases have to be trimmed less often

80gr ttsx, lots of speed and bullet that can handle it

280 Rem AI is near 7mm Mag specs, so it works there, just not on 243 Win.
I checked the same thing many years ago about going to 243 AI. Saved money and shot more.

Have the barrel re bored to a .264 aka 6.5 in either 260 or 6.5 Creedmore...ought to be about the same recoil in 100gr bullets in 243 & 264...more than one way to skin this cat.
Ron

Um, can't or do that. A new barrel would be the way to get that done.

.243 is 6mm.

OP,

I'm with Chad. The right load and the right scope and the good ole' 243 is pretty salty. I worked up a load for a friend's and took it to 800 yards no problem, and that was with 95 gr SGK"s. Upgrade your scope before you start re-chambering.

.264 minus .244 is double the amount of bore difference needed to bore one out according to the guys at Delta - Clearwater (formerly LaBounty) Reboring....from when I talked to them 4-5 years ago. Depending on rifling I was told .007 was the absolute minimum and they liked .010 or better ...or as a rule of thumb 2 calibers in the jump. I was trying to get a .257 25-06 done into a .264 6.5-'06, and they would not guarantee it.
Ron

.264 minus .244 is double the amount of bore difference needed to bore one out according to the guys at Delta - Clearwater (formerly LaBounty in Idaho) Reboring in Oregon....from when I talked to them 4-5 years ago. Depending on rifling I was told .007 was the absolute minimum and they liked .010 or better ...or as a rule of thumb 2 calibers in the jump. I was trying to get a .257 25-06 done into a .264 6.5-'06, and they would not guarantee it.

www.Deltagunshop.com, open the home page & click on Clearwater Reboring button, cut rifled reboring rifle barrels under 26"s start at $225 reboring only, & rechamber & reboring start at $425...and options from there.

Might try Dave at ITD in Minerva Ohio too, I know he said last Fall he could do a re chamber 7x57 into a 280 AI with no sweat for around $100...take the barrel off, rechamber and intall with headspacing...he shot me down on doing a 6.5x57 into a 6.5x'06 as the rechamber would not completely clean up on a x57 case ...and I think he rebores barrels as well. Great Prices on Douglas barrels. www.itdcustomgun@yahoo.com
Ron

I didn't mean it couldn't be done. I know if you suggest it, it's true.

Seems more cost effective to buy another barrel. Button rifled, pre-chambered, on the low end, cut rifled and a smith to chamber and crown on the upper end.

Lots of ways to look at changing a caliber, but putting a pencil to it is only one factor vs a new barrel. Another would be if the existing barrel has sights or a finish you wanted to keep and cannot be cheaply duplicated. Time to get a new barrel ordered and built to change twist and/or resurrect a wore out barrel is another factor also. I'd really like to do a 243 to 260 or 25'06 to a 280AI rebore in a SAKO 579 or AII/AIII/L61 IF I could find a tired SAKO donor at a rightious initial price.

In the 7x57 Mauser conversion to a 280 AI in a NIB Zastava I was looking at doing, the cost was about $100 plus freight both ways ar about 'nuther $50 + can do all the barrel to reciever connection cleanup work if any is needed at a nominal cost at the same time in the same diameter & twist of an existing barrel....the killer for me was the outside of the cheaply finished Zastava in the factory stock or a stock replacement. The 7x57 Zastava was $600 NIB + frt & FFL transfer to start with...but I see 243's all the time in full length Mauser Mark X's & assorted clones & some FN's at $300-$350 on GB that could be turned into anything from .257's to non MG 375'S with the #2-#3 diameter 24" barrels, without getting to far off in the weeds.

Lots of guys, or semi trained gunsmith's with out all the required equipment who can do some or most of the work except for the rebore itself are the primary market for the Clearwater folks I would think. However since I am dangerous with flat edged screwdrivers & round point shovels THAT is outta the question for sure.
Ron

I think Mr. Ackley himself said the standard 243 was already where it worked best.

It works out to about the same ballistics as a standard 6mm rem. I believe...

...or within the deviancy of MV's from chamber & barrel to chamber & barrel...

Rule of Thumb I was always told...in 308 based cases or smaller the gain in AI'ing is simply less Trim to Length time from less case stretch with the sharper 40* AI shoulder...and not as much benefit gain in the 28* RCBS shoulder by that same margin.
Ron