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Old May 27, 2014, 10:26 AM   #1
FLChinook
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Hand load 7 Rem Mag to equal 280 AI?

Two of the arguments in favor of the 280 Ackley Improved over the 7 RM are 1) 3 ft-lb less recoil and less "bark", 2) not quite so hot so longer barrel life. Apparently, the penalty for this is small as the 280 AI has almost the same ballistic performance as the 7 Rem Mag.

The 7 Rem Mag cartridge is a little shorter and fatter so it's a bit of apples and oranges. With this in mind, should it be possible to hand load the 7 Rem Mag to get exactly (in theory) the same performance as the 280 AI and have the same recoil, "bark" and barrel life?

In other words, can one have a 280 AI without the inconvenience of a less common cartridge?

Thanks
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Old May 27, 2014, 10:37 AM   #2
Jim Watson
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There are some numbers in the loading manuals called "starting loads".
I bet one of them would be pretty close to a .280 AI or even a .280 Rem.
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Old May 27, 2014, 10:39 AM   #3
Brian Pfleuger
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Considering that the starting load with the 7mm RM are almost exactly the same fps as max loads in the .280AI, yes it should be very easy to do that in terms of fps.

You may have troubles with low case fill, as in accuracy and consistency may suffer. This is where QuickLoad really shines. You can give it the bullet, cartridge and speed you want and it will tell you which powders will do it.

I'll check on it later if somebody else doesn't first.
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Old May 27, 2014, 11:09 AM   #4
jmr40
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Seems like you're splitting hairs any way you go. In the real world the differences in recoil and performance between 7 mag, 270, 280, and 30-06 are almost indistinguishable.

A 270/130 @3200 fps
A 30-06/150 @3100 fps
A 280/140 @3050 fps
A 7 mag/140 @3200 fps

are all pretty darn close in performance. I don't see 280 AI making much difference.

I've fired all of the above loads and in comparable weight guns cannot detect the 2-3 ft lbs of recoil difference.
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Old May 27, 2014, 12:28 PM   #5
old roper
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My 280AI I used one load with R-17 other is from Nosler manual using 160gr AB start load 57.5gr/IMR-7828 @ 2856fps and max at 61.5gr/IMR-7828 @ 3043fps and that's with 26" barrel.

I started my workup load using 56.5gr/IMR-7828 @ 2823fps and worked up to a max of 60.5/IMR-7828 @3058fps.

I started 53gr/R-17 @ 2834fps max at 56gr/R17 @ 3046fps.

I haven't chronograhed any of the loads using Berger 180grVLD yet.

Nothing against this site but want to find out about 280AI get on Nolser site (forum.nosler.com)guys are shooting factory 280AI and custom. One of the moderator (JD338)is shooting custom 280AI.
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Old May 27, 2014, 06:22 PM   #6
Kimber84
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I don't know about a 7 RM, but my Ackley thumps my brain like no other gun I've ever fired. Granted the gun weighs in the mid 5 lbs, but I also had an 06' , same gun and it never felt this bad. I'm running 139g SSTs at around 3050 fps, I think that's on the lower side of a Rem Mag.

Are you wanting to download the 7 RM to reduce recoil and yet mimic the ballistics of the AI?

By the way, my Ackley is going to the smith this week to have a brake put on, I just can't stand the violent recoil anymore, it's a nuisance.
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Old May 28, 2014, 09:34 PM   #7
thekyrifleman
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I think you should be considering loading the 280AI to match the Rem 7Mag!!!! With 140's the Ackley can keep up, but go to 160 or 175 and the 7Mag leaves the 280 Ackley in the dust!!!!. Typically recoil is not much different due to increased weight in the 7mag platform....
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Old May 28, 2014, 09:49 PM   #8
Brian Pfleuger
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Ok, here you go... I asked QuickLoad to give me 3,000fps with a 140gr Hornady SST in 7mm RM....

It looks like a good candidate would be IMR4831. At 62.5gr, it predicts 94% case fill and 100% burn in a 24" barrel with a speed of 3042fps.

That's very nearly a perfect match for .280AI max loads, at a lower pressure and with only 0.5gr more powder.
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Old May 29, 2014, 04:41 AM   #9
Kimber84
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Quote:
Originally Posted by Brian Pfleuger View Post
Ok, here you go... I asked QuickLoad to give me 3,000fps with a 140gr Hornady SST in 7mm RM....



It looks like a good candidate would be IMR4831. At 62.5gr, it predicts 94% case fill and 100% burn in a 24" barrel with a speed of 3042fps.



That's very nearly a perfect match for .280AI max loads, at a lower pressure and with only 0.5gr more powder.

I like the 4831 in my .280 AI, I'm running it at 59.5 grains with a 139g SST. It's sitting right at 3050 fps. I've dug through Noslers manual and they are claiming some very aggressive speeds in the AI. I believe 60 grains was max charge of 4831 under a 140g bullet, pushing somewhere around 3200 fps ( if my memory is correct) Kinda makes me feel like they're drumming up the numbers slightly to help sell their ammo and custom rifles, as no other load data shows velocities like theirs. Maybe it's the fact that they've done more testing since they established it with SAAMI and are more comfy running hot?? I dunno.
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