280 vs. 280 AI

[35 Whelen]

O.K...I see/read lots of people talking about what an improvement the 280 AI is over the 280. I have owned a 280 for...gee....20 years I guess. Love it. It's my "business" deer rifle and my backup elk rifle.
I also have a 257 AI that I've owned for about 25 years, so I have nothing against the improved cartridges. However, after hot-rodding my 257 AI and thinking I had to run 100 gr. bullets at 3300 fps and nothing else would do, I realized two things:
1) I was destroying a nice little Mexican Mauser action, and
2) Using realistic, safe loads, I was only gaining about 100 fps over the standard 257 and handloads.
So.....

I see the 280 AI has about 100-125 fps over the standard 280. Has anyone here ever compared the actual downrange ballistics of bullets fired from these two cartridge? By that I mean if a 280 AI starts a 160 gr. partition at 3000 fps, and a 280 starts the same bullet at 2900 fps, how much real difference is there in the two?
I come up with just about 50 yds. difference in residual velocity, and about 3" difference in drop at 500 yds. assuming a 200 yd. zero.
So, is it worth the extra powder? Just curious of everybodies thoughts...

35W

 

[Coal Dragger]

Well I own a .280AI and in my own biased opinion it is worth selecting over the standard chamber if we are talking about an individual who reloads, or one who is comfortable with only using one brand of factory ammo. I would also add the caveat that it is only worth it if we are talking about initial purchase, or a re-barrel project as I would not see any pressing need to spend extra money to have a new chamber cut in an already existing barrel in good condition.

As for the "extra" powder used, that argument is kind of silly in my opinion since on average we are talking about a difference in powder charge of around 4-5 grains more for the .280AI using the same powder. Seeing as how there are 7000 grains in one pound of powder the real difference in how far a pound will get you is virtually the same. So as an example a using a max charge of IMR4831 under a 140gr Accubond will net you about 125 rounds at 56 grains in a .280, and will get you 116 or so in a .280AI at a max charge of 60 grains. The difference in velocity between the two loaded to max is roughly 150fps by the way.

 

[35 Whelen]

Actually it isn't an "argument" on my part. Like I said, I have nothing against improved chamberings. Just soliciting opinions, making conversation.

The difference in velocity between the two loaded to max is roughly 150fps by the way.

After my initial post I went to the Nosler website to look at their data for the AI. I was surprised to see they use a 26" barrel. I used to chronograph my particular load (55.5 grs. IMR4831; 160 gr. Partition) for my particular 280 (old Ruger 77 re-chambered FROM a 7x57) everytime I sighted it in for hunting season. But the velocities were boringly consistent year after year no matter the lot of powder, so I haven't checked in it a 4 or 5 years. Without going to the shop and referring to my load log, the slowest reading I recall was 2910 fps, the fastest wouldn't have been too much more. The crazy thing is, the barrel is only 22". Wish I had some way of know what the velocity of my load in my rifle would be out of a 26" tube, or what Noslers velocities with th AI would have been out of a 22". Certainly that 150 fps difference would have been much less. I find it interesting how rifles can be so individual when it comes to handloading and obtained velocities.

I know in the 50's, 60's and 70's the Ackley Improved cartridges were very popular. But I wonder if the advent of the affordable chronograph and magazines such as Handloader whose authors do indepth research on subjects such as this, has diminished the popularity of improved cartridges?

Regards,
35W

 

[Coal Dragger]

Good questions. My rifle has a 24" barrel and I would not want any shorter a barrel for the AI. My guess is that with slower burning powders the extra barrel length would be pretty useful, with the faster burning powders showing less increase or decrease in velocity due to barrel length changes.

FYI the Nosler 6th edition manual has both the .280 and .280AI test barrels listed as 26" with a 1-9 twist, a Lilja for the .280 and the .280AI a Wiseman. I wouldn't personally see any real valid reason to go with the 26" over a 24" in either caliber since there is not a huge amount of powder being burned.

 

[DM~]

I built a light weight 280 Rem. "mountain rifle" in the late 70's, and personally, i don't think in "this" case the imp is worth it at all.

I've shot a lot of big game with my 280, and i've never felt i needed another hundred fps to get the job done.

At the "same pressures", the AI just doesn't gain much at all...

DM

 

[451 Detonics]

There is an excellent article in the April issue of Shooting Time, included reloading and ballistic info...should be on the news stands now. ( mine comes in the mail and has been here over a week)

 

[TonyRumore]

There are actually two versions of the 280 Ackley. One has a 30 degree shoulder and the other a 40 degree shoulder.

Tony

 

[Picher]

I've considered improved cartridges over the years and don't think they're worth the trouble. A friend had one rifle "Improved" and the gunsmith did such a bad chambering job, the barrel needed to be shortened and rechambered. That was on a .30-30 Winchester 94, which caused a lot of work to fix, including shortening the magazine tube.

Improved caliber rifles are often not as desirable as a trade-in or private sale. If you do the deed, you'll pay for it on both ends.

The added performance is limited by the amount a shoulder can be fire-formed from the original cartridge dimensions. The amount of performance is somewhat minimized by the added case capacity, which must be compensated for by a few grains of powder, just to equal the velocity of the parent cartridge.

Fireforming rounds wastes bullets, primers and powder to accomplish the task and accuracy during the process is generally poor. Cases then last for maybe 7-10 loadings, then others must be fireformed to replace them.

 

[bobnob]

If I was building a custom rifle or going for a rebarrel on something special this is one AI cartridge I would seriously consider - though I'll go on record that I generally believe the commercially available rounds are all we need.

The fact that Nosler are making factory brass is a big incentive, and that dies and data are quite readily available is a factor.

A 7mm Rem Mag performer in a non belted case, an extra round in the mag, and lots of projectiles to pick from.

Maybe if I ever shoot out my 270 barrel. If it does the job even better than the 270 then it's gotta be a good thing!

 

[Coal Dragger]

Who cares about fire forming cases, when factory .280AI brass is available, and so is factory ammo? These arguments that it isn't worth the trouble because of the wildcat nature of the round are officially outdated and invalid given the availability of factory ammo, brass, and rifles.

This is how easy it is to reload for .280AI vs .280: Go to store that sells ammo and reloading supplies, find box of Nosler Custom brass in .280AI or order it, pay for said box of brass. Take brass home, and then reload it as normal for any other bottle necked rifle case. Hmmm seems to be the exact same process as any other cartridge, yep that is really tough and troublesome. In fact last time I was at Cabelas in Rapid City I was able to find .280AI brass but none at all for the standard .280 Remington.... go figure.

 

[bobnob]

The commercial rounds are all you'll "need", however that needs some qualification I suppose.

Even though the Ackley Improved concept has been around for a long time, they are a demonstration that there is a better way to design a round for use in a sporting rifle than those concepts that were around 100 years ago and more.

So while the 270 Winchester is great, it's widespread popularity is now based on a brand name as much as performance. I don't think anyone would really argue that it is as "good" a round as the 280 AI.

I'll never swap my 270 for a 280 AI, but when it needs a new barrel well I would consider it.

By the way I know the post is about 280 vs 280AI but I am using the 270 Win only to make my point because it's been around so long, is so popular and is considered a great round. Just wanted to point out there are sometimes better ways of doing things but it's tradition that stops us sometimes.

 

[Maverick223]

Just stumbled upon this thread, but I think I have decided against the .280AI. With the Rem. 7600 already chambered for the .280Rem. and having only a 22.5in. bbl (which is a mite short for my taste to begin with) I don't believe the expense and possibility of feed/extraction problems are worthwhile. OTOH, if I were doing a custom build it would take a bit more consideration.

 

[Coal Dragger]

Maverick223,

I would have to agree with you there on it not being worth your time. Also not sure if the 7600 would be strong enough to tolerate warm reloads even if you were to decide to, it may be but I am always leery of loading to max recommended loading as it is, much less for a pump action.

 

[GooseGestapo]

Interesting question.

I was deliberating on a simular idea. I was going to rechamber a Remington M7 in 7mm08 to either 284win or rebarrel to 6.5-284.

After chronographing the original barrel and factory ammo, I decided to leave well enough alone. I was getting 2,900fps with a 140gr bullet, so decided to leave the rifle as-is. It's one of my favorite rifles now.

As far as the 280AI is concerned, it is probably a better cartridge than the 7mmRemMag, but as one poster already mentioned.... resale value.... I think I'd just go to the local pawn shop and pick up a used 7mag and call it good.

During hunting season, a trip to the local public range will reward you with anywhere from a dozen to perhaps 50 7mag cases, so componenets are readily available. Factor in the cost of a set of Lee RGB dies and you can be in the 7mag business for less than $300.00 at current prices.

Something to consider....

 

[35 Whelen]

I absoLUTELY think it's a better cartridge than the 7mm Mag if you're a handloader. And you know, there's just a certain allure to a cartridge that has "improved" attached to its name.
35W

 

[HOOfan_1]

I've never picked up a 7 Rem Mag at my range. Most of it is steel 7.62x54R, followed by steel 7.62x39, followed by 5.56x45/.223, followed by .308, followed by .30-06, a few 5.45x39, some 8x57, in 25 trips a couple of 7x57 and a couple of .243. The overwhelming majority of the stuff I find is military surplus too. I always do a thorough sweep around the area too, and my range discourages cleaning up brass you don't intend to keep just so others can pick it up if they reload.

 

[Maverick223]

I have to agree on the .280AI being theoretically better than the 7mmRM, at least from the point of efficiency. Similar performance (not quite as good, but you can probably match a factory load with meticulous handloading and a good action) with less recoil, powder expenditure, less costly cases (that can also be formed from readily available .280Rem. in a pinch), and greater magazine capacity (at least in some cases).