I have neither caliber, but i’m just wondering why you 7-08 guys prefer it over the 284. Won’t the latter hold more powder? Does the 7-08 have any accuracy advantage? And...if the 6.5 Creedmore is better than the 260 (minor reasons, but I understand them), why not a 7 Creedmore instead of a 7-08? Won’t the case advantages of the Creedmore work for a 7 Creedmore as well as it does for the 6.5?

This came to me as I was in the uhhhhh, reading room this morning with the couple of reloading books I keep in there. These, to me, are interesting questions. Hopefully Chad or Fireman or some of you other experienced folk can ‘splain’.

I don’t NEED to know, but would like to know, or this will bug me for a few days.

284 Win is a great round, but it really needs a long action to shine. It was engineered as a short action cartridge, but with today's long, high BC bullets, a lot of case capacity would get eaten up seating bullets in a short action. Brass availability is second. 284 Win brass is surprisingly hard to find. Most folks I know end up necking up Lapua 6.5x284. I believe if I was to build a long action today, it would be a 284 Win or Shehane pushing 180's. As for the 7 Creedmoor, I have wondered the same thing. I think it would only pay dividends if you're shooting 150-162+ grain bullets. The 140's have no issue preserving case capacity at mag length in the standard 7-08. When I built my 7-08, I looked into that as an option. Not enough R&D, and seemed like more trouble than it was worth. Time will tell, and I'd be interested to see how a 7 CM would perform with 162's.

For me, it is due to brass. I have made 7mm-08 brass from 243, 260 Rem, 7mm-08 (of course) and .308 Win. I'm never in trouble of finding brass that will work.

Stick a long 162 gr in it, and OAL gets fairly long.

.284 Win case 2.170" 66.2 gr H2O
7mm-08 case 2.035" 52.2 gr H2O

My assumption (which is dangerous for everybody) has been to run the bullets I like in a 284 Win, I would be on a long action. Judd's .284 Win ammo would not fit in a standard short action, he just confirmed that with me in a text.

Step up to 7mm-08 A.I. and in my opinion, I have achieved the highest performance possible of any cartridge, in a standard short action, when talking foot pounds of energy delivered, low ES, and lack of wind drift. This year, I've safely pushed a 162 gr ELD-X, at 2822 fps MV out of a 24" barrel. That equates to the same trajectory to 800 yards as a 6.5 Creedmoor shooting a 140 gr at 2780 fps MV, but a significant amount more energy delivered. And the energy delivered is noticed at how hard it swings my steel as compared to the 6.5 Creedmoor.

As far as necking up a 6.5 Creedmoor, you will not fit 43.0 gr of H-Varger in that brass, as compared to a 7mm-08 A.I.

Cody replied while I was writing. Looks like we are on the same page.

7mm creed is a thing but not overly popular at the moment and that is likely due to the poor brass qc of Hornady brass. With the new Lapua brass it might be a fun option but may not get you any gains over 7mm-08 depending on setup.

Like said before 284 needs a long action to shine. It can be run in a medium length action (defiance, FNH 300wsm length or older mauser) but still is better served in a long.

603Country, dee is really our resident expert on the 7mm-08 A.I. He helped me when I dove into it. I've got lots of time with the standard 7mm-08, but when it came to the A.I. version, dee answered some questions I had, when I was making sure I was on the right track.

I think I've about burned the tube up on my first one. Gotta do some checking but hot a reamer and extra barrel ready yo go.

Thanks for the info. And I wondered about the 7-08 AI, but honestly didn’t figure that going AI would achieve much in that cartridge. But if you can push a 160gr bullet to almost 2900, that’s impressive.

Like I said, i don’t plan to buy a 7mm anything, since I have a 260 and a 270, and that’s all I need for hunting. Truth is, I don’t even need them both, but i’m not selling either one. If, however, I did plan to sell and then buy one gun, it might be a 6.5-284. But I won’t. That Tikka 260 I got from Chad, with the 20 inch Brux barrel, is just so danged accurate, easy to handle, and points like a dream, that I cannot imagine a rifle i’d like more. The 260 made me park the Sako 270 in the safe, and brother that Sako is sweet.

But...I was wondering about the 7’s. Thanks for the info. I do appreciate it.

I have a .284 in a LA, 175 elite hunter is pushing the envelope on mag length. Its a task to brass prep. Its pushing 175's 2850 with a 28'' barrel, could get a little more fps but starts to open up past 600. Its my least favorite to load for but my favorite to shoot. Its a rare breed so brass will not be as abundant as 08.

I figure ALL brass prep is a task, but I think you're saying that it's more so for the .284 W. Would you mind telling a little more about that? How is it any more work than any other bottle-necked rifle case?

If you buy lapua brass it will be 6.5x284, you'll have to neck it up with a mandrel, then its common after a few firings it will form a donut in the neck, you'll have to ream the inside of the neck. To prevent donut's you need to turn the necks to get the brass to flow correctly and omit dounts in the necks (the brass I neck turned before shooting hasn't formed donuts / the brass I didn't neck turn formed donuts after 2-3 firings). The donuts are minimal but its a inconsistency, some people I shoot with don't worry about it to much and only ream the inside. Norma is now making .284 brass but its just as $$$ lapua, I bought alot of lapua brass from the same lot so I can't justify buying Norma and tossing the lapua.

Thanks for taking the time to explain that. I did not consider the conversion and the fact that you pretty much have to by 6.5x284 anymore. I guess I'm pretty lucky being able to suit my needs by necking that brass down to 6-284. Donuts are a thing I enjoy with coffee.

Spg , Are you using bushing dies? I ask because I expanded then sized on a FL 284 die and no donuts yet.

Yep, FL bushing die. As long as I turn the necks prior to shooting there fine, its a one time thing and I don't have to worry about it. I have two other guys shooting the same set up and one uses non bushing FL dies and he has the same issue, I turned the necks on some new brass for him and he hasn't had any issues after 8 firings. I'm not talking about visible donuts, you have to measure the neck wall thickness throughout the length of the neck to determine the donut, like I said its very minute.

Long action 7mm, but not magnum, the first thought that pops in my head is 280 AI. Where does that fall in the discussion?

Can get A.I. brass without fire forming, and it is a very salty cartridge. My favorite 7mm on that action size.

My thoughts exactly JG. Just personally, if I was going to build a 7mm on a long action, the 280 AI is what I would do. My old rebuilt shoulder probably isn't up to repeated banging away with a belted mag.

Getting the most out of a short action though, that is the trick. 7mm-08 in the AI version is a tough nut to crack, trying to improve on it. Bottom line is no matter what cartridge you choose you have the same magazine length restriction (OAL), coupled with the same bullets. There are some work-arounds but most of them aren't simple.

There's also the 7SAUM that's similar to .284win/shehane/280AI if you want to go SA.