Converting a 7mm Mag. to ?

May 8, 2011
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#1
I have an older Remington 700, chambered in 7mm Mag. I plan on building a long range rig out of it. I dont care for the round and want to change it over to something else. I don't want to modify the bolt face, and ammo should be able to fit into a standard AICS magazine. I was sold on the .28 Nosler till I learned how bad of a barrel burner it is. I want something that will retain its accuracy out to around 3,000 rounds. So far the only thing I can think of is the .300 WM. Anybody have any other suggestions of calibers I should be looking at for this project?
 

spife7980

Full Member
Feb 10, 2017
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#3
I want something that will retain its accuracy out to around 3,000 rounds. So far the only thing I can think of is the .300 WM.
Good luck with that, I would hope for half your desired round count out of a winmag and anything over that would be bonus. I also wouldnt expect the 7mm to be all that much worse than the 300 in barrel life. Pushing bullets with that much powder doesnt coincide with high barrel life, in fact its the opposite. You have a big caliber to go faster and that will erode the barrel. If you wanted a 7mm with a 3000 round life look at the 7-08 or stick with what you have and be satisfied with good enough.
 

fdkay

Gunny Sergeant
Nov 27, 2009
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#6
7LRM.
Splits the difference between the 7RM and the .28 Nosler.
or
.30-375. Same thing, .375 Ruger necked down. About 5 grains more capacity in the same envelope as the .300 WM, without the retarded belt. You can run slower powders for the same velocity and might be able to extend your barrel life a couple of hundred rounds.
Uses the same magnum bolt face.
Anything with that much powder behind it is going to burn up the barrel.
 
Dec 2, 2013
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Rome, GA
#7
I second the 7LRM, Brass is easy to get, easy to load for and performs very well with 180 Berger Hybrids. As long as you don't max out you powder load you should get north of 1600 round barrel life.
 
Mar 26, 2006
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#11
Define "long range" but "long range" and 3000 round barrel life don't typically go together. You get one or the other.

The rifles I have which I consider long range are 243AI, 300WM, and 338 Edge hunting rifles, and a 284Win F-class rifle. I don't pretend any of them will see 2000 on a barrel much less 3000.

The best you can do is probably a 308 with fast twist and heavy bullets.
 

W54/XM-388

Online Training Member
Oct 1, 2005
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#12
You can get really good barrel life in the 3000+ round range on the .338 Lapua Magnum, if you run the 250gr rounds without overdriving them (such as running the factory Lapua 250gr ammo) & you don't run it too hard.
 

MJB13SRT8

308SR90 on Old 2004 SH
Feb 21, 2017
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Memphis, TN
#13
Your going to have a hard time trying to get 3000 rounds out of a 300wm out of more than a dozen barrels I have had in 300wm I have only had 1 make it to 3000 most went between 1500 and just a little over 2000 and I had one that went in 900 rounds.

Montrose
 

sandwarrior

Gunny Sergeant
Apr 21, 2007
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#14
What's wrong with 7 rem mag?
Lack of top notch brass...

But, he is correct. For a decent long range rig, a tightly twisted 7mm Rem Mag will get pretty much what you want. The only way to extend the life of a .300 WM is to download it to 30-06 levels almost.

Another thought, but I don't know how they'll feed is the WSM's. We're now getting really high BC .30 cal bullets, but they're kinda spendy. The top end 7mm's are up there too, just not as bad.
 

steve123

Lt. Colonel
Mar 16, 2008
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Flagstaff, AZ
#15
300 Saum or 300 WSM. Or their 7's.

You'll need to load down for practice/steel to extend barrel life and I'm not insinuating you'll get 3000 rounds out of a barrel but these should exceed the bigger cases barrel life.

I watched Charles Greer set a 1000Y benchrest record years ago with his 300WSM literally right in front of my eyes down in the pits, I think it was 3.9" for 10 shots. It's kind of like the 6PPC equivalent of a 30 cal.

AND NO BELT, I hate belts.

I use 30-375R and 6.5Saum. 6.5 Saum is one of the most underrated cartridges out there. Awesome ballistics, good barrel life with H1000, lower recoil. I'd do a 1-7 twist for those newer heavier bullets.
 
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May 8, 2011
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#16
Your going to have a hard time trying to get 3000 rounds out of a 300wm out of more than a dozen barrels I have had in 300wm I have only had 1 make it to 3000 most went between 1500 and just a little over 2000 and I had one that went in 900 rounds.

Montrose
What was so special about that one barrel? Different make, twist, profile?
 
May 8, 2011
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#17
What's wrong with 7 rem mag?
Well, its kind of a funny story. Had a good broadside shot on a deer, (must have jerked the trigger) and when i shot the deer dropped in its tracks, as would be expected. Didnt see an exit hole at first till I skinned it out. The bullet nicked the shoulder blade, went up hit and followed the spine, hit the hips and came back in my direction. Esentually the bullet did a U turn on me. Kind of put a bad taste in my mouth for the caliber. Its a family gun so selling it isn't an option, but since that evening in the woods in 2006 I havnt taken it out of the safe. So something needs to happen to get it back in the game and out of the safe.
 

W54/XM-388

Online Training Member
Oct 1, 2005
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#18
Well, its kind of a funny story. Had a good broadside shot on a deer, (must have jerked the trigger) and when i shot the deer dropped in its tracks, as would be expected. Didnt see an exit hole at first till I skinned it out. The bullet nicked the shoulder blade, went up hit and followed the spine, hit the hips and came back in my direction. Esentually the bullet did a U turn on me. Kind of put a bad taste in my mouth for the caliber. Its a family gun so selling it isn't an option, but since that evening in the woods in 2006 I havnt taken it out of the safe. So something needs to happen to get it back in the game and out of the safe.
The fault was in your aim point & your ammunition selection.
The 7mm Remington Magnum is a fine hunting cartridge that does a lot well.

Here is some good reading on that round from someone that basically hunts animals for a living:
https://www.ballisticstudies.com/Knowledgebase/7mm+Remington+Magnum.html

(his books if you buy them have the actual pictures of results on animals to go along with the explanations).
 
Feb 26, 2017
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#20
Well, its kind of a funny story. Had a good broadside shot on a deer, (must have jerked the trigger) and when i shot the deer dropped in its tracks, as would be expected. Didnt see an exit hole at first till I skinned it out. The bullet nicked the shoulder blade, went up hit and followed the spine, hit the hips and came back in my direction. Esentually the bullet did a U turn on me. Kind of put a bad taste in my mouth for the caliber. Its a family gun so selling it isn't an option, but since that evening in the woods in 2006 I havnt taken it out of the safe. So something needs to happen to get it back in the game and out of the safe.
How is that the fault of the 7 mag again? Ive killed 10 elk with a 7 mag. So the bullet made a U turn, what kind of bullet were you using? Also, if it even made it back to you, how much energy do you think it would have?
 

sandwarrior

Gunny Sergeant
Apr 21, 2007
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#21
Well, its kind of a funny story. Had a good broadside shot on a deer, (must have jerked the trigger) and when i shot the deer dropped in its tracks, as would be expected. Didnt see an exit hole at first till I skinned it out. The bullet nicked the shoulder blade, went up hit and followed the spine, hit the hips and came back in my direction. Esentually the bullet did a U turn on me. Kind of put a bad taste in my mouth for the caliber. Its a family gun so selling it isn't an option, but since that evening in the woods in 2006 I havnt taken it out of the safe. So something needs to happen to get it back in the game and out of the safe.
I would agree with W54/XM-388,

That was either a poor choice in bullet selection or an absolute anomaly. I'm betting on the latter. 7mm is a great 'killing' caliber. Bell killed many elephants with a 7x57, Eleanor O'Connor stayed right up with her husband, Jack, with a 7x57. A step up in power to the 7mm Rem mag is all you need for anything in the world, if it is legal to do so.

I'm of the opinion that the "blowin' up on the hide", "U-turn in the animal", "Went through and did nothing" etc. etc ad nauseum are excuses which turn into perpetuated myth and perpetuated further by competitors that say, "You need my bigger and/or better cartridge/bullet". It always leads me to ask, that until the iowa buck was shot, the Jordan buck (biggest whitetail ever) was killed with a .25-20 WCF. It's about bullet placement first. You can add to that by using better built bullets, but again, without good placement it means nothing. A 7mm Rem Mag that you can shoot well will kill anything.
 

RNWRKNP

Sophisticated Redneck
Dec 13, 2017
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#29
Lack of top notch brass...

But, he is correct. For a decent long range rig, a tightly twisted 7mm Rem Mag will get pretty much what you want. The only way to extend the life of a .300 WM is to download it to 30-06 levels almost.

Another thought, but I don't know how they'll feed is the WSM's. We're now getting really high BC .30 cal bullets, but they're kinda spendy. The top end 7mm's are up there too, just not as bad.
Nosler makes outstanding 7 mag brass....
 
Feb 18, 2012
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Middle Tennessee
#32
I’m in the same boat. Can’t decide to stick with 7mag or change it up when I rebarrel. It’s a mostly factory Remington Sendero. I really like a 7 mag for hunting although it’s debatably overkill for what I hunt with it. It more accurate than me with Norma brass 168 Bergers and h1000.
 
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