Short Barreled 7 Rem Mag

Jordan Smith said:
I shoot it out of the 7RM and the .280. The 7RM is currently down for maintenance, but I'm using the 162 AM out of the .280 at 2947fps ave. I'm using 60gr of IMR7828SSC, Fed210, and RP brass.

I'm not sure what you mean by "at what distance", but I can only assume that you're talking about elevation correction? At 950 yards I'm dialing in ~22MOA, depending on the day.
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at Homestead?
 
I'm not a long range shooter.
600 yrds used to be my limit, but now it's more like 500, with 400 preferable.

I hunt a fair bit, And most of my shots are well within 200 yrds, so I practice most at those ranges..
 
rgv said:
here you say (regarding the 280 and 7RM), the big case and the small case get the same velocity



and here you say (regarding the 375 RUM and 375 H&H), the big case in a short barrel gets the same velocity as the small case in a long barrel, i.e. big case outperforms the smaller case.



it can't be both.
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When a large capacity cartridge is mated to a short barrel, its advantage over a smaller capacity cartridge chambered in a barrel of equal length cannot be realized. A 22" barrel might be optimum for the smaller cartridge but might only allows 85% of the potential velocity of the large capacity cartridge to be realized. Thus in the case of the 7 Ultramag vs the 7 mag, 7mag vs the .280 or in the case of the .280 vs the 7-08, the shorter the barrels become, the more similar the velocities are.
 
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sealhunter said:
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the 7RM has about 15 yrds greater point blank range,a little more at best..

at what distance is the 7RM giving you an extra 100 yrds of range with 220 fps more speed...I am very eager to know, sounds like you're getting over 50 yrds more point blank range with the 7RM over the .280....???

For me, I shoot a 7mm-08 at about 300-340 fps slower than the 7 RM
some loads a bit closer, some further apart, but I'd say 300-340 fps on average slower with the same bullet..

The kicker for me, is that the 7RM is gaining 300 fps by using 23-27 grains more powder...

So in other words, it uses roughly 50% more powder to get another 25-30 yrds PBR... with another 300-350 fps.

I find it fitting that the guys who think an inch in length makes a gigantic difference, are also the ones who own magnums...;)
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The little 7mm-08 is quite an efficient performer in a 24" barrel. With the lighter 139 class bullets in 24" the 7mmRemMag is not alot of gain for alot more power. This I agree.:agree:

The 7mm-08 is but a flash in the pan when trying to compete against the Mag with the upper weight class rounds.;)

I drive 175BTSP from my 24" 7mmRemMag at 3050 @ 15 feet, thats the early 60s claimed factory ballistics, all done safely and not over pressure for my Rifle. Try to achieve anything near that in your 7mm-08. I think not, here you are clearly outclassed. Anyone who can read a 2000 yd external ballistic chart will see what freight the Big 7 will take into the next county with the high BC heavy projectiles.


If you shoot Whitetail in a light carbine of 18.5 to 22 inch barrel , get a 7mm-08. If you want to run the full spectrum of Bullet weights in the "IDEAL" bore diameter(.284), versus downrange energy, versus comfortable weight Rifle, then get the "Big 7". The 7mmRemMag is a good performer in 24" barrels, biting at the "Weatherby original marvel" ,the 7mmWeatherby Magnum, that was so overbore it needed at least 26" to work its magic.

Jim Carmichael was no Dummy, when he discovered this round and sang its praises, rightfully so as his forebearer Jack O'Connor did with the wonderful .270Win! Outdoor life was truly blessed in those days.:wave:

The high velocity load i listed will be hard on throat erosion, just as remington initally found with the original ballistics for the 7mmmag. If its accurate and its a Hunting round, worked up, Rifle zeroed and used for the field ,than why not. If it is used for hundreds or thousands of rounds per year in precision Rifle than NO.:)
 
Boomer said:
When a large capacity cartridge is mated to a short barrel, its advantage over a smaller capacity cartridge chambered in a barrel of equal length cannot be realized. A 22" barrel might be optimum for the smaller cartridge but might only allows 85% of the potential velocity of the large capacity cartridge. Thus in the case of the 7 Ultramag vs the 7 mag, 7mag vs the .280 or in the case of the .280 vs the 7-08, the shorter the barrels become, the more similar the velocities become.
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How does that explain how you stated that a 7RM and 280 with 22" barrels get the same velocity?

They won't.

Your own example of your 20" RUM matching a 24" H&H proves that the big case always goes faster than the small case.

If you'd said that the performance differential between the 7RM and 280 was reduced when used in a 22" barrel, that would have been one thing, but suggesting there was essentially no difference once barrel lenght was reduced to 22", is wrong.
 
RememberTheSomme said:
The little 7mm-08 is quite an efficient performer in a 24" barrel. With the lighter 139 class bullets in 24" the 7mmRemMag is not alot of gain for alot more power. This I agree.:agree:

The 7mm-08 is but a flash in the pan when trying to compete against the Mag with the upper weight class rounds.;)

I drive 175BTSP from my 24" 7mmRemMag at 3050 @ 15 feet, thats the early 60s claimed factory ballistics, all done safely and not over pressure for my Rifle. Try to achieve anything near that in your 7mm-08. I think not, here you are clearly outclassed. Anyone who can read a 2000 yd external ballistic chart will see what freight the Big 7 will take into the next county with the high BC heavy projectiles.


If you shoot Whitetail in a light carbine of 18.5 to 22 inch barrel , get a 7mm-08. If you want to run the full spectrum of Bullet weights in the "IDEAL" bore diameter(.284), versus downrange energy, versus comfortable weight Rifle, then get the "Big 7". The 7mmRemMag is a good performer in 24" barrels, biting at the "Weatherby original marvel" ,the 7mmWeatherby Magnum, that was so overbore it needed at least 26" to work its magic.

Jim Carmichael was no Dummy, when he discovered this round and sang its praises, rightfully so as his forebearer Jack O'Connor did with the wonderful .270Win! Outdoor life was truly blessed in those days.:wave:

The high velocity load i listed will be hard on throat erosion, just as remington initally found with the original ballistics for the 7mmmag. If its accurate and its a Hunting round, worked up, Rifle zeroed and used for the field ,than why not. If it is used for hundreds or thousands of rounds per year in precision Rifle than NO.:)
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Sorry, I just shoot moose and elk and bears and stuff with a TSX 140 or 120 doing 2800 or so,... but if I ever feel the need for that edge the 7RM has, don't worry, I'll come back and read all up on it again ;)
 
I have owned several 7mmremags, as well as a few 7mmstws, and I wouldn't have either with a 22" barrel. If I am going to burn the extra powder, deal with more recoil, and reduced barrel life, I will go with a longer barrel, and use more of the cartridge's potential.
 
Boomer said:
When a large capacity cartridge is mated to a short barrel, its advantage over a smaller capacity cartridge chambered in a barrel of equal length cannot be realized. A 22" barrel might be optimum for the smaller cartridge but might only allows 85% of the potential velocity of the large capacity cartridge to be realized. Thus in the case of the 7 Ultramag vs the 7 mag, 7mag vs the .280 or in the case of the .280 vs the 7-08, the shorter the barrels become, the more similar the velocities are.
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Newer powders mitigate this effect to some degree...
 
stubblejumper said:
I have owned several 7mmremags, as well as a few 7mmstws, and I wouldn't have either with a 22" barrel. If I am going to burn the extra powder, deal with more recoil, and reduced barrel life, I will go with a longer barrel, and use more of the cartridge's potential.
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It's always a good policy to build the rifle to balance properly. The rest will fall into place...
 
It's always a good policy to build the rifle to balance properly. The rest will fall into place...
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I balance the gun out, but considering the ballistics, the recoil, the handling, and the barrel life.And to me, the best balance, is reached by using a cartridge at, or close to it's potential. If I want a 20" barrel, I will go with a 7mm-08, if I want a 22" barrel, it will be a 280rem, but for a 7mmremmag, I want at least a 24" barrel.
 
sealhunter said:
Sorry, I just shoot moose and elk and bears and stuff with a TSX 140 or 120 doing 2800 or so,... but if I ever feel the need for that edge the 7RM has, don't worry, I'll come back and read all up on it again ;)
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Just so less informed shooters understand your 7mm-08 is not a short-action version of the 7mmRemington Magnum, and not get sidetracked with only part of the equation to the External Ballistics of both.;)
 
stubblejumper said:
I balance the gun out, but considering the ballistics, the recoil, the handling, and the barrel life.And to me, the best balance, is reached by using a cartridge at, or close to it's potential. If I want a 20" barrel, I will go with a 7mm-08, if I want a 22" barrel, it will be a 280rem, but for a 7mmremmag, I want at least a 24" barrel.
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I hear you, but I doubt you'll get 3250fps from a 22" barrel from a .280 like I am from a 21.5" 7RM...
 
I hear you, but I doubt you'll get 3250fps from a 22" barrel from a .280 like I am from a 21.5" 7RM.
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I wouldn't be shooting a load that produces 3250fps with a 140gr bullet out of a 7mmremmag with a 21.5" barrel either.I value my safety too much for that.Metal fatigue is cumulative.
 
stubblejumper said:
I wouldn't be shooting a load that produces 3250fps with a 140gr bullet out of a 7mmremmag with a 21.5" barrel either.I value my safety too much for that.Metal fatigue is cumulative.
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3350fps isn't out of the question with the right powder, a 24" barrel, and a strong, modern action.

3250fps with 2.5" barrel isn't unreasonable. I'll be checking the pressure in my rifle with a strain gauge soon...
 
a 21-1/2" 7mm Rem Mag might best be described as a cheap and quick way to a 280 Ackley Improved which is all the rage these days...;)..no custom rifle or Cooper required...a quick "cut and crown" and you're there...$50 maybe?...and you can buy ammo at Canadian Tire.:D
 
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