Talk me out of a 7mm-08AI

C

cbh560

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Martensville, SK
I've been collecting parts for a while, with the thought in mind that I was going to build a 7mm-08AI for medium to long range hunting (max ~700 yards) with 120 to 140 gr projectiles nearing the 3000 fps mark. I have everything I need to put my rifle together, but am having second thoughts on my cartridge choice. What I have:

- Rem 700 short action, .473 bolt face
- HS Precision Gen 1 S/A DBM
- 7mm, 9 twist barrel blank to finish at 22"

-all the other goodies required to make it go bang

So...are there any suggestions as to a better or alternative 7mm chambering that utilizes the parts I already have and won't require a bunch of modification or machining work?
 
Sounds like a nice build. I think you would be better served with a 24” barrel shooting 162gr for your long range shooting and hunting. If you want another suggestion a 284winchester would work well with your action and you could skip the fire forming.
Have fun with it and let us know what you decide
 
Bare said:
Sounds like a nice build. I think you would be better served with a 24” barrel shooting 162gr for your long range shooting and hunting. If you want another suggestion a 284winchester would work well with your action and you could skip the fire forming.
Have fun with it and let us know what you decide
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The barrel is carbon wrapped, so no option on going any longer. The whole idea behind this rifle is that it will resemble my heavy target rifles in appearance, fit, and function, but in a package at or lower than the weight of most factory produced hunting rifles. Being that it is going to be light(ish), I'm also attempting to avoid heavy recoil, although I don't really expect that much recoil in any short action cartridge.
 
cdn shooter said:
Sounds like a nice rifle, 700m on game with a 120-140 is maybe asking a bit much though.
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Id want a 7 mag of some sort shooting 160 accubond or heavier if I wanted to shoot at game at 700yds. A 139gr Hornady sst with a muzzle velocity of 2950 has almost 2700 ft lbs energy. At 500 yds, those numbers are down to 2059 fps and 1300ftlbs. From 400 to 500yds you loose over 200ftlbs energy, so by the time that pill gets to 700yds you'd be looking at something like 900-950 ft lbs, and ~1800fps. A 7rm shooting a 162 eldx still has 1775 ft lbs at 500, and should be around 1350 ft lbs at 700 (which is higher than the 7mm08 at 500).

Either way, you'll need to know your drops and ranges really well to hit game at those distances, and the wind better be dead calm...
 
Ackley has 6% more case capacity than the regular 7-08, so velocity increase will be about 1.5%. 40 fps apples to apples
 
brybenn said:
275 rigby. Doesnt do anything your choice doesnt but it sounds right
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Problem is, the 275 Rigby [AKA 7x57] is too long for that 700 Short action. I have 2 - 7x57 rifles, and love the chambering, but
it requires over 3" of magazine length to work properly. Remington 700 SA is only 2.8"
I owned a 7-08 AI for quite some time. It was a great rifle, and was flat enough with 140's at almost 3000 to hit reliably out to
500 yards plus. Dave.
 
What Dave said mirrors my 280 Remington where I use the 140 grain Barnes TTSX at 3000 fps.
The BC is 0.406 and it falls below 2000 fps in the 450-475 yard range.
In order to start with a 3000 fps velocity and keep it over 2000 fps at 700 yards then a BC over 0.600 is required.
These figures were extracted from the Nosler Reloading guide #7.
The 2000 fps is based on Barnes suggestion for reliable opening.

Will follow with interest once you determine what route this might take you.
 
If you need the extra FPS, you'd be better of with a 280 or 7mmMag or just live with a std 7-08 which is not a bad option as is.
 
I think the only other option is to go with a 284win. The problem with it, is the bullets have to be seated deep to fit the 2.800 mag length. You might be able to modify the action slightly to take a longer length, talk to your gunsmith. Its easier to stick with 7-08.
 
cdn shooter said:
Sounds like a nice rifle, 700m on game with a 120-140 is maybe asking a bit much though.
Click to expand...
The 120-140 grain will typically only be used on deer sized and smaller game ie. whitetail, mule deer, and antelope (if I ever win that lottery). the 9 twist barrel should allow me to load up in bullet weights.

Suther said:
Id want a 7 mag of some sort shooting 160 accubond or heavier if I wanted to shoot at game at 700yds. A 139gr Hornady sst with a muzzle velocity of 2950 has almost 2700 ft lbs energy. At 500 yds, those numbers are down to 2059 fps and 1300ftlbs. From 400 to 500yds you loose over 200ftlbs energy, so by the time that pill gets to 700yds you'd be looking at something like 900-950 ft lbs, and ~1800fps. A 7rm shooting a 162 eldx still has 1775 ft lbs at 500, and should be around 1350 ft lbs at 700 (which is higher than the 7mm08 at 500).

Either way, you'll need to know your drops and ranges really well to hit game at those distances, and the wind better be dead calm...
Click to expand...

I'm not a fan of the big magnums and honestly don't find them all that necessary, not to mention I don't have a magnum bolt face or a long action. I've always been of the opinion that if a guy knows his rifle/load and its limitations it really shouldn't be an issue. The 9 twist barrel will allow me to load up in bullet weight if necessary. I have a 30-06 that shoots 150-180 gr bullets just fine and that will be my primary rifle on bigger game (ie. moose/elk) I'm looking for something a little different in this rifle.
 
cbh560 said:
The 120-140 grain will typically only be used on deer sized and smaller game ie. whitetail, mule deer, and antelope (if I ever win that lottery). the 9 twist barrel should allow me to load up in bullet weights.



I'm not a fan of the big magnums and honestly don't find them all that necessary, not to mention I don't have a magnum bolt face or a long action. I've always been of the opinion that if a guy knows his rifle/load and its limitations it really shouldn't be an issue. The 9 twist barrel will allow me to load up in bullet weight if necessary. I have a 30-06 that shoots 150-180 gr bullets just fine and that will be my primary rifle on bigger game (ie. moose/elk) I'm looking for something a little different in this rifle.
Click to expand...

You won't have issues with bullet weight. The heavy (175+) 7mm bullets take up a lot space in the case if they're gonna fit your magazine though. If I wanted to hunt at 500+ yds I would want a magnum. Nothing wrong with the 7mm08, it just doesn't have the oomph I would want for those ranges.

That said, my next rifle is going to be a lightweight 7mm08. It's going to be my grad present to myself once I find a real job. I plan to try the 150gr Scirocco, and as long as they shoot good I'll be set for anything I can hunt in BC out to 300yds+.
 
With the right bullet and load it will do it, but right at the border line.

If it makes you happy, why not.

140 grain Berger VLD hunting may be a good option. .510 BC @ probably 2950ish fps.
 
Eagleye said:
Problem is, the 275 Rigby [AKA 7x57] is too long for that 700 Short action. I have 2 - 7x57 rifles, and love the chambering, but
it requires over 3" of magazine length to work properly. Remington 700 SA is only 2.8"
I owned a 7-08 AI for quite some time. It was a great rifle, and was flat enough with 140's at almost 3000 to hit reliably out to
500 yards plus. Dave.
Click to expand...

Missed the "short" saw the 473. You are correct
 
I really like my 7-08. I think to stretch the most out of it for Long range i went with the 162 grain ELDs. 0.670 G1 in the ELD-M Launching them just over 2700 fps using a 26" barrel and varget. You could prob get faster with different powders, but i had a lot of Varget on hand so that's what im using for the time being. In my environmentals i dont go subsonic until beyond 1200 meters. I'm thinking barrel life should be pretty good as well.
 
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