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NitroXAdministrator
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Is the 7mm Rem Mag slow and never achieved predictions?
      #371531 - 16/11/22 07:04 PM

Ha ha, a confrontational question. I read in an article recently, possibly posted on the forums, that the 7mm Rem Mag, is flaccid and never achieved magnum velocities. Or similar wording.

Some of these armchair hacks writing weekly serial BS are really pathetic and boring within their drivel. Often all academic and so few stories of actual use.

The worst is that dude who makes videos of him sitting behind a desk with boxes of ammunition and published ballistic charts.

Back to the 7mm Rem Mag and not long ago. It was regarded as a hot magnum. In South Africa often regarded as a nimrods rifles and too fast to be effective. Slow heavy bullets preferred. But it was very popular and highly regarded.

Myself I have a sedate 7x65R still not used. Need the ammo. Louis has some brass for me still I hope! Must get it sent!!!

I'd love a .275 Mauser M98 in a suitably classic or styled rifle.

If a magnum, some sort of 7mm SEvH. But a 7mm Rem Mag would be acceptable.

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DarylS
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: NitroX]
      #371536 - 17/11/22 03:30 AM

The 7mm Rem Mag., as with many other ctgs., failed to achieve published ballistics. Something on the order of 2,860fps with 175gr., which is just about achieved by the .280 Rem. IMP.
On the other hand, my old 1970 Hodgdon manual has the 7 mag pushing 175's at a top vel. of 2,938fps with H570 (discontinued) and 2,918fps with H870.
There may be other powders today, like Magnum and H1000 that will push them to just over 3,000fps.
My newest Hodgdon Annual Manual lists only 2 loads over 2,800fps, one with IMR 7977 @ 2,822 and IMR 8133 @ 2,879fps.
So, yeah- I was never impressed by it, although I did try it twice. Back then, the best powder was H and IMR4831 for just over 2,800fps.
Today, those two powders are listed at 2,660fps and 2,710fps with maximum listed loads.


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Rule303
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: DarylS]
      #371548 - 17/11/22 08:17 PM

never been interested in the 7 Rem mag. Knew a couple of blokes who swore by it, but they had a bastard of a time finding a load that shot well. Once they found a powder and bullet combo that seemed to work they then had to play around with seating depth. I don't know if this was common with them but that was just too much work for my liking.

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Homer
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: Rule303]
      #372890 - 05/01/23 07:39 PM

G'Day Fella's,

I agree with you blokes, the 7mm Rem Mag, ain't that much better than a .270 Win, especially with lighter bullets.

I do own a M70 Classic (Stainless, All-Terrain) model, in 7mm RM with a 24" barrel.
I have only ever loaded it, with lighter 120grn bullets (Nosler B-Tips & Barnes X, both Moly coated), at a Maximum Safe Working Load (MSWL) of 3340fps.

As an example, I also own a Rem M600/Mohawk, in .308 Win with a 20" barrel.
I can get 3025fps out of it, with 125 grn B-Tips, so it is only 315 fps behind the 7mm RM, with 20 grains less powder.
At 200 to 300 meters, there would bugger all difference, especially to any animal, that you shot with either.

This 7mm RM's saving grace is, it will shoot 1/2" to 5/8", 3 shot groups, at 100 meters ...... so I do like it. I do wonder, how much of an increase in fps it would have, if it had a 26" barrel ...... but it doesn't, so.

D'oh!
Homer

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93mouse
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: Homer]
      #372891 - 05/01/23 08:00 PM

I have used it in Namibia for Warthog, Kudu and Hartebeest - quite way out - worked just fine in Sauer 202 with RWS TIG bullets. Would I be buying one? No. Would I use it if offered? - Definitely!

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NitroXAdministrator
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: 93mouse]
      #372894 - 05/01/23 09:24 PM

My usual thought seeing that question is "what predictions"? Its been around for decades of actual use. Who cares about predictions from way back when? Except some flaccid gun hack writer.

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3DogMike
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: NitroX]
      #372985 - 09/01/23 01:49 PM

Quote:

….(snip)…..some flaccid gun hack writer.



SNORT !!!
Just sent my wee dram of Scotch whisky out thru my nose at that one …..Bravo!
PS: The visual of a "flaccid gun hack writer" is not for the 1) sober & 2) the faint of heart.
-Mike

--------------------
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- Anon

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eagle27
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: 3DogMike]
      #372986 - 09/01/23 04:48 PM

The exert below has been copied from Sierra reloading data for the 7mm Rem Mag and is a fair reflection on this venerable cartridge. I have also read somewhere that the 7mm Rem Mag is near the top for sales of reloading dies.

Those that espouse that 7mm cartridges based on the 08 and 06 cases come close to or equal the 7mm Rem Mag have little idea of ballistics and are talking bullshit. With the correct powders the Rem Mag can be loaded just like any other belted magnum and will always have a good edge over any smaller capacity case.

From Sierra loading data;
The 7mm Remington Magnum is, first and foremost, a hunting cartridge
and has been used to take virtually every big game species in North America,
including big bears. Realistically, it is probably at its best when used in long range,
open country hunting typical of western big game territory. While its primary
use is in the hunting fields, the cartridge’s flat trajectory and inherent
accuracy has attracted the interest of competitive shooters as well. Eight years
after its introduction, it was used in conjunction with Sierra’s 168 grain
Match King to win the prestigious 1000 yard Wimbledon match at Camp Perry.
At this writing, the U.S. Secret Service counter-sniper teams are armed with
custom-built 7mm Remington Magnums. Considering their stringent requirements
for 1000 yard accuracy, this is quite a recommendation for the versatile
7mm Remington Magnum.

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mchughcb
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: eagle27]
      #372990 - 10/01/23 12:14 AM

Seemed to be popular in Nevada for pronghorn.

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tinker
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: mchughcb]
      #372991 - 10/01/23 12:51 AM

Quote:

Seemed to be popular in Nevada for pronghorn.



Still is

--------------------
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DarylS
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: DarylS]
      #372992 - 10/01/23 05:51 AM

Quote:

The 7mm Rem Mag., as with many other ctgs., failed to achieve published ballistics. Something on the order of 2,860fps with 175gr., which is just about achieved by the .280 Rem. IMP.
On the other hand, my old 1970 Hodgdon manual has the 7 mag pushing 175's at a top vel. of 2,938fps with H570 (discontinued) and 2,918fps with H870.
There may be other powders today, like Magnum and H1000 that will push them to just over 3,000fps.
My newest Hodgdon Annual Manual lists only 2 loads over 2,800fps, one with IMR 7977 @ 2,822 and IMR 8133 @ 2,879fps.
So, yeah- I was never impressed by it, although I did try it twice. Back then, the best powder was H and IMR4831 for just over 2,800fps.
Today, those two powders are listed at 2,660fps and 2,710fps with maximum listed loads.




These are current book values. Your own personal data might vary. As noted here at NE before, with my standard .30/06 with 24" bl. I get 2,964fps at the muzzle using 165gr. SST's.
I'm quite happy nay, tickled with that and within normal hunting ranges there is bugger all difference to the 7mag. The 7mm may have advantages in other areas or other uses, but the numbers do not lie.

--------------------
Daryl


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DarylS
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: DarylS]
      #373011 - 11/01/23 04:55 AM

Just got my new 2023 Hodgdon's Annual Manual.
Interesting loads for '06 cased rounds, especially for the old '06.
165gr. top - 3,003. 12 powders over 2,900fps
175gr. top - 2,883. 11 powders over 2,800fps
180gr. top - 2,857. 6 powders over 2,800fps

The difference between this ctg. and the 7mm Rem. Mag. is actually smaller than previously thought - over normal hunting ranges.
The 7mag appears to hold less than 100fps advantage in most "hunting" bullet weights.
With the canister (general public availability) powders available today, the '06 just keeps getting better.

--------------------
Daryl


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tinker
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: DarylS]
      #373012 - 11/01/23 05:01 AM

Some of the new powders are amazing, getting fantastic velocity with safe pressures

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DarylS
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: tinker]
      #373017 - 11/01/23 08:14 AM

Yes indeed. Seemingly more with the standard head sizes, than the belted magnums. Oh well.

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Daryl


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NitroXAdministrator
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: DarylS]
      #373037 - 11/01/23 06:50 PM

People need to remember, a .284" 160gr and a .308 160gr or 165gr are NOT the same.

A smaller bore has more friction. But an equal weight bullet better penetratration, ceterus parabus, and a better potential ballistic coefficient.

***

Also I have trouble understanding shooter logic. If "modern" powders can improve some cartridges so much why a belt on the outside of a cartridge means an often larger capacity case can't also be improved in velocity similarly?

In addition the Gun hack writers rave on about modern cartridges fat, short, straight walled being "efficient".

I have a real problem with unsupported by any actual objective and independent evidence scientific claims.

Like the "bubble" which allegedly forms in front of a meplat flat bullet IN FLESH .... A bubble may well form in flight in gas, is air. Does not mean a "bubble" in a solid ie flesh occurs. Independent objective evidence? Always lacking. Sure some ballistic gel test by the seller or hack. But one result? Perhaps the best only shown. From the maker I'd want to see TEN comparative gel tests. By an verified independent tester.

Same with cartridge efficiency. Sure a short fat cartridge MIGHT burn the powder better? But it might not. Long and thin might with reasonable width. We are talking about fire here. Compressed thick often burns lesser?

If short straight fat IS more efficient .... And just because hacks repeat it endlessly does not make it true. Remember how once "one had to have a cartridge with a magnum belt!". Then " only a rimless cartridge is good, not those magnum belts". Then it became "only straight wall and fatbonly". Pfffffft!

Myself I KNOW a sloping sided cartridge like an Nitro Express or Vintage cartridge EXTRACTS better. A SUPERIOR characteristic for a dangerous game cartrudge used in hot or tropical climates. My guess, also for icy frigid climates ...

Whenever I see 2+2=5. I get distrustful.

If there is more efficiency, what is the increase 0.5%, 1%, 5%, 20%? I think any efficiency increase is very minor. And largely irrelevant.

To test I would want to see two cartridges, equal bore, same bullet, equal powder, same powder capacity. Same barrels, twist, length in front of the chamber. One cartridge longer, thinner, more sloping. The other short, straight walked, fat. What is the velocity difference? Is there any way to test unburned powder? 100 shots from each test.

If a .30-06 can be souped up, I'm sure a 7mm Rem Mag can be as well.

--------------------
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...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
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NitroXAdministrator
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: NitroX]
      #373038 - 11/01/23 07:04 PM

On the 7mm front, I only have a 7x65R.

The 7x64 was once reported as the most popular German hunting cartridge. (?). I used one tonshoot a Norwegian moose. A very useful cartridge. The 7x65R is the break open equivalent.

The Americans tried to copy it with a .280 of somecwannabe name.

The obsolete dead old finished excellent 7x57 is making a comeback.

While it's "superior" replacement the 7mm/08 is truly dead and being forgotten.

I like the 7mm Rem Mag as almost vintage.

I shot a 7mm STW once at some rois on permit 600 yards away, pushing a bullet at 4000 fps. I missed.

I've always liked the obscure 7mm SEvH vintage cartridges.

But I shoot my .39-06 at game more than anything else. . Excluding small game. If new powders are so good, maybe I need to revist loads ... Ha ha, as if ... Not until my powders run out ...

--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"

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Rule303
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: NitroX]
      #373041 - 11/01/23 08:04 PM

The original claim for short fat cartridges being more efficient was based on the clam that the Primer flame would ignite a greater percentage of the powder. True or not I do not know. What I do know is that if this is true then different powders will most likely be required. Probably slower powders for the same calibre and bullet.

I know one bloke who is getting damn near 358 Norma Mag velocities out of his 35 Whelen using a new powder. I do know that long throating a chamber and seating the bullets out a bit does increase the Muzzle Velocity. Roy Weatherby knew a thing or two.

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NitroXAdministrator
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: Rule303]
      #373046 - 11/01/23 11:41 PM

Quote:

The original claim for short fat cartridges being more efficient was based on the clam that the Primer flame would ignite a greater percentage of the powder. True or not I do not know. What I do know is that if this is true then different powders will most likely be required. Probably slower powders for the same calibre and bullet.

I know one bloke who is getting damn near 358 Norma Mag velocities out of his 35 Whelen using a new powder. I do know that long throating a chamber and seating the bullets out a bit does increase the Muzzle Velocity. Roy Weatherby knew a thing or two.



The last increases case volume so more powder can be used.

Some guys just always seem to get higher velocities as well.

--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
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DarylS
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: NitroX]
      #373053 - 12/01/23 03:45 AM

These newer powders favour the '06 more than they favour larger cases. In other words, the burning rates of the newer line of powders are made for cases smaller than the belted cases. It's quite simple, really.
There is one new slower burning powder, but it does not work as well in the 2 1/2" magnum cases as it does in larger yet cases.
The data I have presented is straight out of the loading manual with pressures as well.

--------------------
Daryl


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Rule303
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: NitroX]
      #373059 - 12/01/23 08:21 AM

Quote:

Quote:

The original claim for short fat cartridges being more efficient was based on the clam that the Primer flame would ignite a greater percentage of the powder. True or not I do not know. What I do know is that if this is true then different powders will most likely be required. Probably slower powders for the same calibre and bullet.

I know one bloke who is getting damn near 358 Norma Mag velocities out of his 35 Whelen using a new powder. I do know that long throating a chamber and seating the bullets out a bit does increase the Muzzle Velocity. Roy Weatherby knew a thing or two.



The last increases case volume so more powder can be used.

Some guys just always seem to get higher velocities as well.




True, but even if you use the same amount of powder there is a velocity increase when long throated. Is it enough to make any real world difference, I'd say not. Long throating comes handy when using mono mental bullets as you do not have to seat them down into the powder space.

My Rem 700 as a 270 would barely make 2900fps with a 130 grain bullet. Same load in my Styer Prohunter gives me 3200fps. So, yes, the barrel can make a difference. I now use 140 grain 270 bullets and these chrony at 3100fps.

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DarylS
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: Rule303]
      #373061 - 12/01/23 09:37 AM

That's moving for a 140gr. Ed Matunas wrote up a loading manual, all his own testing, I think. In the verbiage, he wondered why some people swore at .270's while others loved theirs. He did his tests, using a number of .270 rifle and was quite shocked at what he found. Similar to your findings, Rule303, he had one factory .270 that with factory 130gr. ammo, it ran right at 2,750fps, while one actually produced 3,150fps - same barrel length, same ammo.
The other rifles, 5 or 6 of them, produced in between these two extremes.
He surmised the fellow who was getting 3,150fps was extremely happy, while the other fellow found his .308 to kill much better and be flatter shooting as well.
He then contacted Remington and they told him they did not like producing 130gr. loads as it was almost impossible to get stable results with it in a factory load. NP with 150gr., but those 130's were trouble.
My buddy's wife used her .270 with 130TTSX @ 3,000fps and killed all her African plains game with one shot each, including the nice Kudu. I posted a picture of that one a few years ago. She's a hell of a good shot, too.

--------------------
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NitroXAdministrator
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: Rule303]
      #373075 - 12/01/23 11:09 PM

Quote:

Quote:

Quote:

The original claim for short fat cartridges being more efficient was based on the clam that the Primer flame would ignite a greater percentage of the powder. True or not I do not know. What I do know is that if this is true then different powders will most likely be required. Probably slower powders for the same calibre and bullet.

I know one bloke who is getting damn near 358 Norma Mag velocities out of his 35 Whelen using a new powder. I do know that long throating a chamber and seating the bullets out a bit does increase the Muzzle Velocity. Roy Weatherby knew a thing or two.



The last increases case volume so more powder can be used.

Some guys just always seem to get higher velocities as well.




True, but even if you use the same amount of powder there is a velocity increase when long throated. Is it enough to make any real world difference, I'd say not. Long throating comes handy when using mono mental bullets as you do not have to seat them down into the powder space.

My Rem 700 as a 270 would barely make 2900fps with a 130 grain bullet. Same load in my Styer Prohunter gives me 3200fps. So, yes, the barrel can make a difference. I now use 140 grain 270 bullets and these chrony at 3100fps.



Yes and that's still a case volume capacity improvement. More space, more powder, higher velocity achieved. .

--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
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DarylS
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: NitroX]
      #373083 - 13/01/23 04:12 AM

Quote:


Yes and that's still a case volume capacity improvement. More space, more powder, higher velocity achieved. .



Absolutely, as long as you have the correct powder to do it.
Without that vital component, the ballistics fall short of the actual potential.

When a case is oversized to the bore, for the powders in use for it, it's ballistics suffer compared to smaller cases with appropriate powder for them. By "suffer", I am saying that smaller, more efficient cases can approach the ballistics of the larger case & they do.

The larger the case for a given bore size, the less efficient it is in the amount of increase in fps compared to the grains of powder weight it needs to produce top speeds.

Barrel length also comes into the equation.

--------------------
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Rule303
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: NitroX]
      #373108 - 13/01/23 02:13 PM

Quote:

Quote:

Quote:

Quote:

The original claim for short fat cartridges being more efficient was based on the clam that the Primer flame would ignite a greater percentage of the powder. True or not I do not know. What I do know is that if this is true then different powders will most likely be required. Probably slower powders for the same calibre and bullet.

I know one bloke who is getting damn near 358 Norma Mag velocities out of his 35 Whelen using a new powder. I do know that long throating a chamber and seating the bullets out a bit does increase the Muzzle Velocity. Roy Weatherby knew a thing or two.



The last increases case volume so more powder can be used.

Some guys just always seem to get higher velocities as well.




True, but even if you use the same amount of powder there is a velocity increase when long throated. Is it enough to make any real world difference, I'd say not. Long throating comes handy when using mono mental bullets as you do not have to seat them down into the powder space.

My Rem 700 as a 270 would barely make 2900fps with a 130 grain bullet. Same load in my Styer Prohunter gives me 3200fps. So, yes, the barrel can make a difference. I now use 140 grain 270 bullets and these chrony at 3100fps.



Yes and that's still a case volume capacity improvement. More space, more powder, higher velocity achieved. .



No that would be incorrect. I said same amount of powder. So case volume capacity increase but no powder increase and that is only if you seat the bullets further out. Even when you do not seat the bullets further out there is a velocity increase, so same bullet, same powder charge, same overall cartridge length. I should have made this somewhat more clear. This is achieved through the bullet having more distance- albeit very small - to travel before it meets resistance. As said, real world difference in muzzle velocity would be stuff all.

Edited by Rule303 (13/01/23 02:15 PM)

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chuck375
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Re: Is the 7mm Rem Mag slow and never achieved predictions? [Re: Rule303]
      #376803 - 18/05/23 11:59 AM

I get 3000 fps out of my BDL in 270 with 150g Partitions. I believe the 7mm Rem Mag was advertised to do that with 175 bullets. Even if it did, I think it's an awesome cartridge but never felt the need.

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