280 AI vs. 284 Winchester?

[Gila]

First off I think that the 280 AI is a great cartridge and I am not trying to say that one is better than the other. The two seem very close in performance. There are advantages and dis-advantages for both. The 284 Winchester yields virtually the same performance but in a shorter case which is more efficient. With a longer throat the bullet can be pulled further out of the case and the OAL becomes that of a long action cartridge. The 284 Win is one of the best 7mm cartridges for a Tikka T3 action. However factory ammo is limited for the .284 Win and is not found on the shelf very often. The 280 AI on the other hand is somewhat limited by the length of a Tikka magazine, maybe other DBMs as well. 280 ammo is readily available. Brass is available for both although I believe that the 284 Win goes out of stock more often.

I worked up a load for my 284 Win using the 162 gr ELD-X. The goal was consistent velocity and accuracy for hunting. This load is not a max load for this bullet. I compared my 284 Win load to Hornady's advertised ballistics for the same bullet in factory loaded Precision Hunter ammo in 280 AI.

My load for the 284 Win:



Hornady's Precision Hunter 162 gr ELD-X in 280 AI:

 

[Unckebob]

First off I think that the 280 AI is a great cartridge and I am not trying to say that one is better than the other. The two seem very close in performance. There are advantages and dis-advantages for both. The 284 Winchester yields virtually the same performance but in a shorter case which is more efficient. With a longer throat the bullet can be pulled further out of the case and the OAL becomes that of a long action cartridge. The 284 Win is one of the best 7mm cartridges for a Tikka T3 action. However factory ammo is limited for the .284 Win and is not found on the shelf very often. The 280 AI on the other hand is somewhat limited by the length of a Tikka magazine, maybe other DBMs as well. 280 ammo is readily available. Brass is available for both although I believe that the 284 Win goes out of stock more often.

I worked up a load for my 284 Win using the 162 gr ELD-X. The goal was consistent velocity and accuracy for hunting. This load is not a max load for this bullet. I compared my 284 Win load to Hornady's advertised ballistics for the same bullet in factory loaded Precision Hunter ammo in 280 AI.

My load for the 284 Win:


View attachment 585371
Hornady's Precision Hunter 162 gr ELD-X in 280 AI:

View attachment 585376

I don't know where you live, but neither 280AI not 280 REM are readily available in N Texas. The only load I have ever seen on the shelf is the 280AI Nosler ammo using the 140g ballistic tip.

I am a reloader so it didn't bother me when I picked the cartridge for my build.

I would rate both of them (based up what I have read about the 284) as "reloaders cartridges" vs the 6.5CM and 270.

 

[Gila]

I agree they are both primarily cartridges for handloaders. If you hunt New Mexico you will either go to or through ALB or EL PASO where you can replace your ammo with 280 rem (hopefully) if it gets lost. Seems like the shelves are always empty for .270 and 30’06 because everyone buys it up as soon as it goes on the shelf. I had a difficult time for almost two years finding the 270 and 300 win mag ammo that I wanted to shoot, which is why I got into reloading. I am glad I did because I really enjoy it and I can shoot more often. The 284 Win has better performance than I had expected. The COAL shooting VLDs is about 3.1” for my chamber, which easily fits inside a Tikka DBM.

 

[8grenade]

Both are great cartridges. I was always going to build a 280ai and had not considered a 284 until a friend of mine that shoots F-class (600 and 1000) switched from 7 saum to 284. I am a bench rest shooter but not an F-class competitor. I tend to keep my hunting rifles in the 24" or less for barrel length and for my Black Hills rifles I try to stay in the 22" range. I sacrifice the bit of velocity for the ease of handling. I like your thinking on the 22" barrel. At that length and 160 gr. bullets, the difference between the two cartridges is negligible. You just burn less powder to reach the virtual same velocity. I like building rifles with cartridges (and variants) that will use Lapua brass. With that said, I exist in the realm of the bench rest psychosis of neck turning, and all the rest that goes with that world. Analysis paralysis. But I love my 284 win.

 

[elkguide]

Do you like red apples or green apples?

Both are great cartridges. I'm glad that we live in a free country and at such a time when I don't have to choose between those two and only have to decide which one, I want to carry.

 

[BAKPAKR]

If I were building on a Tikka action, I would definitely go with a 284 Win over a 280 AI. I have just started loading for a 280 AI and the COAL restrictions of the OEM Tikka magazine would keep a lot of bullets from being loaded close to the lands. That may or may not be an issue but it would suck if the COAL your rifle liked didn’t fit the magazine. Fortunately, my rifle is Remington 700 based so I don’t have to worry about overall length.

I am betting that if you compare reloads to reloads, and mag length restrictions were not an issue, the 280 AI would still beat the 284 Win by 50-75 fps, on average. BTW - I understand the “I use less powder to get there” argument as I recently rebarreled a 300 RUM to 30 Nosler.

 

[Gila]

If I were building on a Tikka action, I would definitely go with a 284 Win over a 280 AI. I have just started loading for a 280 AI and the COAL restrictions of the OEM Tikka magazine would keep a lot of bullets from being loaded close to the lands. That may or may not be an issue but it would suck if the COAL your rifle liked didn’t fit the magazine. Fortunately, my rifle is Remington 700 based so I don’t have to worry about overall length.

I am betting that if you compare reloads to reloads, and mag length restrictions were not an issue, the 280 AI would still beat the 284 Win by 50-75 fps, on average. BTW - I understand the “I use less powder to get there” argument as I recently rebarreled a 300 RUM to 30 Nosler.

I am sure a good handloader could tweak the 280AI load and get 50-75fps more. But the same can be said about the 284 load. I didn’t reach max pressure but I know I am close to it. With fire formed brass and maybe different powder charge, I think I can get closer to 2950+ for that bullet. I am going to experiment with it after this season is over with. The 284 Win is an extremely efficient case and shoots the heavies very well. Rather ironic that the 284 Win is over 60 years old and was not very popular until the advent of the VLDs. As it turns out the cartridge case was way ahead of it’s time with a 35 deg angle on the shoulder, very slight taper and a base diameter that is only .015 thou less than the 300 win mag. A near perfect design to shoot high BC VLDs.

 

[rmarshall]

The 284 has intrigued me for a long time, but saying that, I do have a 280 AI built on a Tikka. I'm shooting a 160 Accubond, muzzle velocity 3065. It's shoots a lot more accurate than I can shoot, 1/2 MOA or better. I've yet to shoot a deer, but I can say elk and hogs get hammered with the accubond or ballistic tip.
I haven't found myself short changed on magazine length, but I'm not shooting anything heavier or longer. I have no reason too as the 160 AB will work just fine.

 

[wind gypsy]

I am sure a good handloader could tweak the 280AI load and get 50-75fps more. But the same can be said about the 284 load. I didn’t reach max pressure but I know I am close to it. With fire formed brass and maybe different powder charge, I think I can get closer to 2950+ for that bullet. I am going to experiment with it after this season is over with. The 284 Win is an extremely efficient case and shoots the heavies very well. Rather ironic that the 284 Win is over 60 years old and was not very popular until the advent of the VLDs. As it turns out the cartridge case was way ahead of it’s time with a 35 deg angle on the shoulder, very slight taper and a base diameter that is only .015 thou less than the 300 win mag. A near perfect design to shoot high BC VLDs.

Yes, the 284 case is cool and was ahead of it's time. It's still smaller than a 280AI which is closer to SAUM in volume (almost identical) than it is .284. With similar throats and at similar pressures with similarly optimized powders, the 280ai will be faster.

 

[Harvey_NW]

My custom Tikka started out as a 280AI and is currently being rechambered to 284 Win because of the limitations. I was 2gr over book max and smashing polymer tips from recoil, and jumping like .120" to the lands in a SAAMI chamber. Now that I understand more, I'm having the 284 throated tight to a 165/168 with almost identical bearing surface lengths, and that will allow me to go down in weight and have room if need be.

In a BDL with no limitations, I think you can optimize the 280 and squeeze the extra performance, but in a Tikka I recently found a lot of load data where the 284 outran mine by a decent margin with similar components.

 

[XxWeinerZxX]

280 AI has actual support now but the 284 Winchester is just cooler all around. But the AI does beat in by about 100 FPS

 

[Gila]

280 AI has actual support now but the 284 Winchester is just cooler all around. But the AI does beat in by about 100 FPS

That may depend on the load. My 284 Win likes the 162 eld with H4350. Now that the barrel has settled out, I am getting about 2950 fps. But then where I shoot there isn’t very much air resistance or humidity.

 

[max-x]

I have two 284 GAP Match chambered barrels for my T3

162gr to 2900fps
175 eldx at 2830 fps
180/183 at 2800 fps
195gr eol at 2740 or 2830 fps (rl26)

Lots of downrange smash

I think the 284 case design is optimal, esp for the T3 action. The T3 really maxes out at 3.38" oal, so techincally 30-06 length, but with modern low drag dimensions, the 284 case is really the longest which can be used and still mag feed.

 

[goodlife]

Both are great cartridges.

Capacity-wise, 284 Win is basically a .280 Rem, so ~75fps.The cool thing about the 284 is it fits an 'intermediate' action really nicely.

If you are planning to run heavies - 175 or 180gr, overall cartridge length and magazine box length require careful consideration. A .280AI will be hamstrung running at 3.34", a .284win will be hamstrung running at 2.86".

 

[Gila]

I put a 284 Win custom barrel which has the GAP chamber on a 20 year old T3 action without the single feed ejection port. It shoots the 162 gr ELDs so well I am sticking to that load. Fits in a standard Tikka long action mag with a COAL of about 3.07”. I am using a 24 inch barrel to get optimum velocity. The case is wide and short enough to have a relatively centered powder column which should boost powder burn efficiency. I would venture to guess that a shorter barrel would lose less fps per inch of barrel than the 280AI.