.280 AI - Information Wanted

[Jerry D]

What do you guys think of this cartridge?

What can I expect for barrel life?

Recoil similar to a .30-06?

Anything else? Should I go with the standard .280? If so why? I refuse to jump to the 7mm rem mag

 

[TonyRumore]

I had a Sako AIII built in 280AI (30 degree shoulder) for many years. It was very fast. I used to shoot the old 125gr Barnes bullets at 3,500fps.

My dad also has one (40 degree shoulder) and his is a bit slower for whatever reason.

I believe the "standard" 280AI these days will have a 40 degree shoulder.

IMR 4350 was the powder of choice.

Tony Rumore

 

[Mr_Pale_Horse]

Standard 280 brass will be alot cheaper than buying 40 degree 280 AI brass. Forming brass will fall in between the two cost wise.

I am cheap, and the 280 does everything I ever wanted in a cartridge. If you can afford the novelty of a 280 AI, you do get a little more velocity.

 

[Dr. Tad Hussein Winslow]

I just got a T/C Encore 28" .280 Rem, and am considering reaming to .280 AI, but am leaning against it. As strong as Encores are, I should be able to get some borderline-insane velocities from it with regular .280 - more than I want/need really, when you consider barrel burn issues.

 

[navyretired 1]

According to Parker Ackley the 280 AI only realized about 100 fps more that reg. 280 Rem. unless pushed to insane pressures.
The real benifit of 280 AI is case life with less bolt thrust. There are several other benifits but speed is not that much greater.
Recoil is rather mild, it's a ballistic twin to 7X57mm mauser round.

 

[Kernel]

What do you guys think of this cartridge?

It’s a blown out .280 case with a sharper shoulder, holds, maybe, 10% more powder. A typical .280 case holds 67 grains of H20. So, being generous, let’s say a .280 AI holds 74 grains. That “extra” 7 grains will give you a 100 additional fps with a 165 grain bullet, based on my Powley computer calculations.

Remington’s ballistic chart for the .280 Rem shows with a 165gr bullet muzzle velocity is 2,820 fps. Making it an AI out of it should allow you to safely go to 2,920 fps, with no increase in pressure - due to the increase in case volume. That’s what the AI configuration gives. Higher velocity. Same pressure. Larger capacity.

For comparison, the same Remington ballistic chart shows the 7 Win Mag with a 160 bullet doing 2,950 fps at the muzzle. 130 fps faster than the AI, with a slightly lighter bullet. The Win Mag case holds 84 grains. 10 more than your AI case.

Recoil similar to a .30-06?

Remington’s chart shows the .30-06 with a 165 grain bullet doing 2,800 fps at the muzzle. 20 fps less than the .280 with the same weight bullet. Makes sense, since the .280 is nothing but a .30-06 necked down to 7mm. The .280 and the .30-06 both have the same SAAMI pressure spec of 60,000 psi. Converting to AI doesn’t magically confer additional pressure capabilities. Your AI would still be a 60,000 psi cartridge.

“Practical” recoil would be identical, since they throw the same weight bullet at the same speed. The 140 grain bullet is the most popular weight for 7mms. 150’s or 165’s are the most popular for .30 cals. That being true, there's a perception the 7mm recoils less, but it’s due to shooting a lighter bullet, nothing else.

Should I go with the standard .280?

No one can really answer that, but you. Is an additional 100 fps (150 with lighter bullets) worth the cost for the chambering and the custom reloading dies? The cost for custom dies is not insignificant (for some cartridges they‘re outrageous, like $200+ for a 3-die set, but I‘ve got a feeling for the .280 AI they wouldn‘t be too bad - check it out first). IMO the increase in effectiveness on game animals out to 500 yards would be nil. There is a coolness factor to it, though, which you’ve gotta appreciate.

Why not a 7mm WSM? 81 grains of case capacity to roam around in. Load it UP. Load it DOWN. No belt (hate the belt ). Lots of great short actions to choose from. What’s not to like? Hardly more complicated than cutting an AI chamber.

 

[Uncle Mike]

Well, I think ol' Kernel summed it up pretty well...nothing more to add here!

Well one thing...if you want that extra 100 FPS WITHOUT having to go AI, check out the Hornady Light Magnum Ammo.

280 with a 139gr SST at 3110 FPS...that's right there with 7mm REM MAG. performance!

 

[Arkansas Paul]

.280 AI a ballistic twin to the 7x57 mauser? What manual did that come out of?

I'm a huge fan of the .280 Rem by the way, so I don't think it would be worth it going to the AI, but it may be to you. It's your money getting spent. Get what you want. Our opinions are just that. Opinions.