What is the most horsepower you can get in a S/A Accuracy International

[backyardsniper]

Here's the parameters. I have an Accuracy International AI AT. These for those who don't know these are short action switch barrel rigs with a .473 (308) bolt face so no WSM's, they run a magazine that is slightly more generous than some other short action mags. If my measurements are correct it looks like 2.950 OAL is the max I can get in the mag.
If I were going to get a barrel spun up and my goal was to deliver the highest BC bullet down range with the highest velocity possible with the overall plan being to extend my terminal range by having the highest amount of energy on target at distance within the given parameters what cartridge would you all recommend. I'm guessing 6.5 or 7mm is going to be the way to go in order to balance high B.C. bullets with maximum velocity. The 260 Ackley Improved is the best I can come up with. Is there any others out there that I'm over looking?

 

[BoomFlop]

Are you looking for highest velocity or highest energy?

I'd look at a 7mm-08 with a 162 grain ELD M bullet or a 308 Win with a 215 gr Berger for energy.

The 260 AI maybe faster, but the bigger bullets will provide more "horsepower" in my opinion.

I'm guessing you are a Reloader with the 260 AI. Just run a bunch of numbers on different cartridges and bullets and see what you like best. I think the type of game will have a large influence on velocity vs energy.

Good luck
Steve

 

[backyardsniper]

That 215 in 308 isn't a bad idea. I've got a 308 barrel but unfortunately it's a 12 twist. I do handload I should have included that info so Wildcats are fine

 

[North Idaho Hunter]

260 ai, 6.5x55 ai, 284 shehane are what come to mind.

 

[Plinker147]

7mm 08AI

 

[backyardsniper]

Can you do a 6.5x55 in a short action. That's a good idea. Also the 7mm08 AI with the heavies would have some serious thump

 

[Buster Hemlock]

338 Federal or a 338-08 AI could be worth a look depending on what you consider horsepower.

 

[martinakl]

7mm SAW looks interesting. Lapua 308 Palma brass (small rifle primer (SRP)) through a sizing die and ready to roll.

https://westtexordnance.com/7mm-saw/

 

[backyardsniper]

That 7mm saw is a very interesting cartridge. That's a lot of horsepower in a short action

 

[Buck3]

Does your AIAT have a small or large firing pin? If large you might run into problems with a small rifle primers.

Also there is a guy over on the hide who recently made a 6.5 prc on a AISA.

 

[backyardsniper]

I've got a small pin.
Y'all have given me some great ideas so far, I like the 7saw idea as well as some sort of an improved 308 to shoot the 215 bergers. Lots of good ideas, keep em coming. I knew y'all would help me spend my money wisely. Ha ha

 

[adam32]

6.5x284

A 215 in a .308 would be hard to make 2.950" I would think, unless you wanna lose a lot of case capacity.

 

[Barrelnut]

260AI with 156 Gr Berger Elite Hunter in a 7 or 7.5 twist.

 

[backyardsniper]

Could you do a 6.5x284 in a sa. Or even a regular 284? Are those on a .473 bolt face?