243 ackley

[huntwithme]

has anyone ever had a rifle in this caliber. what is your opinion as far as an antelope varmit caliber. I plan on using either a 90 or 100 grn nosler. how much more fps over a standard 243
thanks

 

[BWB]

You should see a couple hundred FPS more out of the AI, maybe more.

 

[sambo3006]

You won't see that kind of velocity unless you want to trash your brass in short order and maybe your rifle also. Most of the Ackley improved cartridges will gain you 50-100 fps when loaded to the same pressure as the standard cartridge. The 22-250 and 250 Savage Ackley improved versions will gain more than that due to the larger amount of taper on the parent case and the subsequent powder capacity gain of the improved version.

 

[BWB]

I have 223AI, 243AI and 6mmAI and all of them are doing close to 200 and some loads over 200 FPS of the parent cartridge. I have roughly 6 firings on the 223AI brass and about 4 on both 243AI and 6AI and haven't lost one case yet (except for the two that went out my pickup window into tall grass)...Just my experience.

I will add I'm not shooting 90-100grain bullets out of any of mine, all are lighter than that. I'm shooting 87 vmaxs out the 6mmAI, those are the lightest. Maybe this has something to do with my findings or maybe my MagnetoSpeed is lying?

I've also never compared the parent and AI version in the same barrel, all my AI barrels are aftermarket - this also will play into things a little. Although I did fireform some 223AI in that same barrel and those were 50vmax's @ about 3550 with and the 50's in the AI case are closer to 3800 - different powders and primers, however...

 

[Derrick in missouri]

I n my 243ackley I'm running 105 berger vld. At 2950 fps in nosler brass and burnin hybrid 100v powder. Used it on antelope 2years ago didnt work well at 534 yards. Make sure to shoot high shoulder as i didn't get good bullet performance at that range in lung area. Needed a follow up shot. THe best thing I have seen in ackley over the parent case is brass life. My nosler brass has 6 loading and have not had to trim one time primer pockets are still tight. Other than that not much different than the regular old 243 win.

 

[sambo3006]

BWB,
Perhaps I came off a little harsh with my comments but I was concerned that the original poster could be led to load to very high pressures to reach a 200+ fps velocity gain. According to John Barsness and other sources as well, generally velocity percentage increase is about 1/4 of the percentage of case capacity gain. For the 243 Ackley this would translate to about a 2% velocity gain and for the 6mm Ackley a 3% velocity gain.

There may be something to the fact that you haven't compared velocity of a barrel first chambered in the standard round and then rechambered to the Ackley round, but I still think that you are probably operating at chamber pressures a fair amount higher than SAAMI max pressures for the parent cartridge. As long as your bolt lift isn't hard, probably not high enough pressure to stress the action but I just wanted to enlighten you on the facts as I have been informed.


Good shooting!

Sam

 

[BWB]

I agree that it's likely different barrels making the biggest difference. I like to do all my fireforming in the "old" barrel, before installing the new. I double checked my book and the 50's out the 223AI are average of 3750, so just as close to 3700 as 3800. That was the cartridge I noticed the biggest change in.

Since the OP didn't specify if he was reaming a barrel or buying new barrel for 243AI, I just posted my experiences.

My bolt lift on all is fine, I've seen some pressure signs but ALWAYS back off. Brass life thus far has been great.

 

[Derrick in missouri]

A word of warning in a ackley chamber !!!!! Ackley chambering usually do not show pressure signs until it is dangerous !!!!! Work up loads very carefully!!!!!!! The same pressure signs you see with parent case may not show up in ackley chamber....

 

[huntwithme]

it doesn't seem there is an advantage from a 243 to a 243ai accept that the cases last longer. is there more of an advantage changing the 25/06 or maybe the 7mm/08 to an ai. my main interest is a good light left handed rifle that is good for antelope up to 500 yards. I was looking at the 243ai the 25/06ai or rebarreling a 25/06 tikka to a 240 weatherby and installing a 26 inch barrel by kreiger. can't rebarrel the 25/06 to a 257 weatherby I have the 25/06 tikka but it has a 22'' barrel. I was going to rebarrel it anyway.
thanks for the help

 

[BWB]

243 and the 25/06 would both easily get you to 500, if you aren't chasing that little "extra" it wouldn't probably be worth it for antelope. IMO

 

[Derrick in missouri]

If your gonna go rebarrel how about the 6.5 -06 the bullet b.c. Much better than 25 cal and has plenty of stoping power. If you just wanting an ackley go ahead and ackley to a 6.5-06 ackley you get same advantage as with the 243ackley . The 6.5 ranks right up there with the 7 mag for long range bullets. Just my opinion but if I were to rebarrel a 25-06 I'd go with the 6.5-06. Won't be many antelope you can't touch with it. Brass is easy to make just get the 6.5 die and run your 25-06 brass in it and you have 6.5-06.

 

[yawn]

I like the 243ai. I had one built one on a BSA majestic and its acounted for a dozen or so deer ( reds and whitetail) from 40yds to 520 in the last couple of years. N560 pushing a 105 vld at 3150 from a 23" barrel works very well. Im up to 9 reloads from the lapua brass with no problems at all.
Heres a little yearing red at a r=touch over 400yds

http://vid194.photobucket.com/albums/z166/yawnphotos/Spikershot31feb2014_zps44b53747.mp4