7mm-08 or 284 in SA w/AI mags

blue_ridge

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Anyone who's loaded these cartridges for use in short action rifle using Accuracy International mags, I'd like to know about the bullets that will fit without extending below the neck junction too far.

I'm pretty sure 175 and 180's won't fit without losing case capacity to the bullet but was wondering about 162 gr A-max or any good high BC bullets that work. I want to compare the loads possible with 284 and 7mm-08 (maybe even 7mm-08 AI) to 6.5x47 and 260 and 260 AI with 139 scenars and similar.
 

Jered Joplin

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Re: 7mm-08 or 284 in SA w/AI mags

You are better off with the 7-08. The 284 is a really tight squeeze in a SA. I own 3 and they are LA's. If you put the bullets out where they belong the 284 comes alive. If you seat them deep you are going to run 7-08 velocities for the most part. To further the 7-08 you can have the mag altered by removing the front tac welded block. You'll have to alter the feed ramp as well but you'll get the extra depth to make the 7-08 shine. Or you could build it on something that utilizes the AW mag. There are multiple options for that as well. We make an action that uses the AW mag and in addition to that there is the Badger M2008, George's Templar, or we have altered Surgeon's and Remington 700's.
 

swd

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Re: 7mm-08 or 284 in SA w/AI mags

Use Seekins WSM bottom metal and you can load out to 3.1". It does take a little machine work on your action to fit it, but the advantage is well worth it. Seekins says it will feed 284 just fine. The 7-08 is no slouch at 1K either though.
 

sandwarrior

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Re: 7mm-08 or 284 in SA w/AI mags

I just built a 7mm-08 with a 1-8" twist. It will push 180's out to 2600+ and 175 SMK's out to 2650". The .284 will handily outperform it, but I suggest a long action. You lose too much pushing the heavy bullets down deep in the case.

Mine is on a Savage short action which is longer than the Rem Short action. The Rem you can only load out to 2.8" Mine are loaded out to 2.95" Using standard Savage bottom metal you can load out to 3.020"

So, depending on what you build it on, you have a length difference right there.

For a Rem 700 action I would go with the long action even for a 7mm-08. For the Savage, you could go with a short action.
 

Bradley

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Re: 7mm-08 or 284 in SA w/AI mags

Jered, have you got any pics of your action posted yet? I had a guy asking about it last weekend and I couldn't find anything on it.

Thanks
 

300sniper

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Re: 7mm-08 or 284 in SA w/AI mags

there was someone on here that did a short action 284 shooting the 162 amax's. it sounds like it worked ok for his purposes but in my opinion, it was seriously handicapped. i have no experience with the 7-08 but if you find his write up on the sa .284, you should be able to compare it to the guys that shoot 7-08 here.

if i can find the thread here i'll post it. if not, i think the poster's user name contained 284 in it.

edit: here is the thread i was referring to. maybe he didn't do as much with the 162s as i had remembered.: http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1384374&page=1

and the write up on 6mm br: http://www.6mmbr.com/gunweek095.html
 

Jered Joplin

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Re: 7mm-08 or 284 in SA w/AI mags

I haven't posted anything on them. We have just been selling them with builds. We have been so busy that I really haven't had a lot of time to post much. I'm trying to leave some of that stuff up to Mark and stay in the back working.
 

Jered Joplin

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Re: 7mm-08 or 284 in SA w/AI mags

Here is one in action. It just happens to be a 284 Win. Did I mention that it's a lousy ass choice for a hunting rifle.
wink.gif


IMG_5603.jpg

 

sobrbiker883

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Re: 7mm-08 or 284 in SA w/AI mags

284 gives better case capacity and you can get the speed easier, but that's in a long action. Jered's pic is a LA.

The above referenced articles show how the 284 has a longer case than a 7-08, and that becomes a double edge sword-you can fit more powder, but the 7-08's case leaves the ogive of amax's on the outside of the neck where they belong.

Everything comes at a trade-off in this game......

That said, I'm enjoying my 7-08 with the 162 Amax's, even if its only going 2725 out of a 22" tube. Runs wind with the 260's and carries good energy downrange.
 

blue_ridge

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Re: 7mm-08 or 284 in SA w/AI mags

I think I'm leaning towards 260, possibly 6.5x47. I was trying to figure if there was a 7mm cartridge that would fit in a short action and run high BC bullets better than a 260.

Sounds like the 284 is bit too long and 7mm-08 wouldn't have any real advantage over 260. I believe both 7-08 and 260 would require me to neck Lapua brass up or down (from 243 or 308). The 7mm 162gr. A-max has a BC of .625 while the 6.5mm 139gr. Scenar has a BC of .615. So, would need to see 2850 or so out of a 26" 7mm-08 barrel to see much if any advantage. I may even go with 6.5x47 just for the ease of loading ready to go Lapua cases, although they are more expensive.
 

BobinNC

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Re: 7mm-08 or 284 in SA w/AI mags

Blue Ridge,

Your forgetting the Nature of Scale. A 6.5mm 139 grain bullet @ 2850 FPS, will be equaled by a 7mm bullet of 175 grains, traveling 150 FPS less (or 2700 FPS).

As an illustration:

Lapua 6.5MM 139 gr @ 2850

1000yd Drop -8.5 Mils -29.3 MOA..Windage 2.1 Mils 7.2 MOA

Sierra 7mm 175 gr. SMK @ 2700

1000yd Drop -8.9 Mils -30.7 MOA..Windage 1.9 Mils 6.6 MOA

How about the 7mm 162 gr A-MAX @ 2700

1000yd Drop -9.3 Mils -31.8 MOA..Windage 2.1 Mils 7.1 MOA

Nearly identical in drift to the 6.5mm 139 gr Laupa, but traveling 150 FPS slower.

For a better explanation try these articles by Bryan Litz:

Part one

Part two

Now you are right, the 7mm-08 does not have any real ballistic advantage over the 260 Rem/6.5 Creedmore/6.5x47 Lapua. But it does have a real advantage in barrel life. It will be better than any of the 6.5 trio.

Bob
 

flyboy

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Re: 7mm-08 or 284 in SA w/AI mags

Just out of curiosity, what will be the use of this rifle. the 260 has great bullets availible for target shooting and they will work on animals to with good shot placement but if you go on a hunt and manage to leave said bullets on the reloading bench (don't ask), will you be able to go down to the store and still bet a loaded ammo with decent balistics.

the 7-08 has some fine factory ammo specifily for hunting with great BC's to boot.

Look at the Hornady superformance 139 GMX in 7-08 for instance.
 

WM5L

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Re: 7mm-08 or 284 in SA w/AI mags

I have 6, 7mm-08 in rifles and pistols and love em all. The round is very easy to shoot and reload for. It dosent use a lot of powder for the FPS you get. Just my .02
 

mwroseberry

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Re: 7mm-08 or 284 in SA w/AI mags

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rosie Palma</div><div class="ubbcode-body">If you're going with a LA, why the 284 Win over the 280 Rem? </div></div>

I was looking into this suggestion. If you look at the 280rem speed numbers compaired to the 7mm-08 the 280 gets the same basic speed with more powder.... Less efficent - if you look at the 284 it beats them both without being necked out. So if you neck it out is should beat them both. Am I missing something here?

I also compaired the 308 to the 30-06 as the 280 is a 30-06 round and the 7mm-08 is a 308. What I find holds true for 30-06 and 308. It simply doesn't make sence unless neck design has everything to do with it. Because for the same velocity you need much more powder in the 30-06 than you run in the 308 using the same bullet.

This thread and reloading just confirms running the 284 over the 7mm-08 or the 280rem. Same velocity with less powder.

Please correct my logic if you find faults in it but this is just strange that the larger rounds don't have more horsepower.

Thanks,
Merritt
 

steve123

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Re: 7mm-08 or 284 in SA w/AI mags

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rosie Palma</div><div class="ubbcode-body">If you're going with a LA, why the 284 Win over the 280 Rem? </div></div>

All things being equal they are very close to each other in FPS.Some shooters like to seat bullets out of the neck shoulder junction.I think you can do that and mag feed with 284,not sure though.If you went 280 AI then you'll see a gain in speed but more recoil,probably less barrel life.
 

gregsjt

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Re: 7mm-08 or 284 in SA w/AI mags

Have you considered a 7mm SAUM, shorter than a WSM and more case capacity than a 284. Plus, someone just announced they are starting to make SAUM brass, I can't remember who. I know it was not Lapua, it might have been Hornady or Nosler. However, I know Norma makes .300 SAUM brass.
 

Lowe Left

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Re: 7mm-08 or 284 in SA w/AI mags

Thanks to all for the insight. It is confusing why the longer 30-06 based cartridges don't seem to use their powder as efficiently as the shorter cases. Interesting topic.