Home Forums Hunting & Shooting Ask The Gunwriters 7mm Remington Magnum?

It's a bit ironic, I suppose, but I'm about to write a blog article on bear and moose rifles, comparing them in a variety of terrain here in N. Ontario. The 7 Rem Mag, .30-06 and .300 Win Mag will be compared in the first of several presentations. Then we'll move on up from there.

I've owned several 7 Rem Mags and one 7 Wby Mag. I slightly preferred the Weatherby. But more than those, the .300 Win Mag was my choice for whatever I might want to hunt under my conditions with a rifle of that class.

I'm halfway between 84 and 85, and for the past 20 years or so, I've preferred Big Bores and mediums to anything in .30-cal or less. Heavier and larger bullets are more efficient in killing power. That's been proven to me many times over. And there I'm speaking NOT of CNS hits but fast loss of blood pressure hits. A bigger hole does that.

Bob

www.bigbores.ca

A little late to the party, but I'll give my input. I am 43 years old and am a big fan of the 7mm Rem Mag. It gives me the most efficient big game general purpose round for hunting everything, possibly short of the big bear. However, Phil Shoemaker said he has seen good results on brown bear using the 7mm Rem Mag and would allow his hunter to use it. Remington's big 7 gives me plenty of velocity, with adequate bullet weight of 160-175gr for large animals like elk or moose, and those heavy 7mms are obviously high BC and SD values, penetrate well, and do so with less recoil than their 30cal counterparts, which to me is a huge factor. The 7mm Rem Mag isn't brutal yet, but the 300 Win Mag, to me, is getting unpleasant. My 160 Accubonds with 65gr RL23 at 3100fps or 175gr Partitions with 63.5gr RL23 at 2950fps will do well for anything non dangerous out to 600 yards with authority, which is farther than I'd like to shoot, but under the right conditions, am able to do so. I think it is one of the greatest hunting rounds ever developed.

Also, as a side note, I found 74gr IMR 8133 with the 160 Accubond at 3150fps in a 26" Remington 700 to be very accurate also. IMR 8133 is just difficult to find. I know my response is after the report, but thought I'd offer it as additional information on the subject. Great article John, as always!

A question for Muledeer, what did you learn from our posts and how did we help you with the article?
I've learned that there are a fair number of our members that are closer to sunset than sunrise. I've learned that many of us have answers to questions we haven't been asked. And I've learned that many of us get caught up in the wonderful minutia of our hobby.
Bflt

I ended up with a 26" Encore barrel in 7mm RMag as part of a trade. I really don't have any use for it here in Ohio, but my Encore with it installed is likely the most accurate gun I have ever shot. So definitely count me a fan.

P.S. I'm 61.

Blackfly1,

I learned the 7mm Remington Magnum isn't popular only among "geezers," who remember all the popularity (and hype) after its introduction in 1962. The average age of the 24hour fans of the round who responded to my question was 56.8 years--which means they were born just about when the 7mm RM appeared. (This is also a little younger than the guy who called it a geezer round, who also admitted to me that the two belted magnum rounds he tends to use have been the .300 Winchester Magnum--which appeared one year after the 7mm Remington Magnum--and the .300 H&H.)

I also learned--or rather, had it re-emphasized--that many Campfire members are eager to respond to any post that allows them to "vote" their opinion, even if their opinion is irrelevant to the post. I wanted to know the age, etc. of fans of the 7mm RM. Instead quite a few expounded on why they didn't like the 7mm RM, and which big game cartridges they preferred. But that's common on Internet forums, apparently because not enough humans get to express their opinions to other people who never asked for 'em. Though I have known some shooters who do spontaneously start lecturing other shooters as soon as they're introduced, about subjects only important to the lecturer.

I was thinking about buying one back around ‘85, but the Baptist preacher that managed a lease I hunted told me that my Model 94 was inadequate for hunting deer in Georgia bottom country. I was younger then and hard headed. My folks raised me in Methodist country.

I hear you MD. I'm a volunteer Line Safety Officer at our county range and I see and hear this often myself. The more I hear stuff like that, the more I value keeping my own mouth shut. I help folks when asked or they are obviously very inexperienced, but I just try to avoid those "smart" fellas.

Cheers,
Rex

Rex,

Ah yes! Have experienced range geniuses a few times as well.

One complained, loudly, on his first visit to a local 100-yard range, that wasn't precisely level--implying that his groups would be smaller if it was....

I've heard it said that a one-eyed man would be king in the land of the blind.

Looks like the 7 Mag is not going to die anytime soon.

John, et. al.
Here's another data point on the apparent difference between your barrel and mine, that some others may benefit from.
Since my rifle almost always develops significantly less velocity than Nosler's published loads, I get kind of sucked into thinking I can start pretty close to max when testing new loads.
BUT, my order of IMR 8133 arrived yesterday and I did some loading to try your excellent load from the recent Handloader article. You used the 160 NAB over 73.5 grains of IMR 8133 with a Fed 215 primer, and got 2954 fps and .58" average groups.
I checked Hodgdon/IMR and they list 75.0 gr as max with the 160 Partition at 3035 fps.
So since I "always" get lower velocities than published, I felt pretty comfortable with loading up three test batches of 72.5, 73.5, and 74.5 of IMR 8133 with the 160 NAB, Fed 215, and a 3.375" OAL, which I tested at the range this morning.
WOW, the 72.5 grain charge gave me 3042 fps! That's 90 fps more than yours with a grain less powder, and a greater speed than Hodgdon's max with 2.5 grains LESS powder. I did not shoot the 73.5 gr or 74.5 gr loads - I'll pull 'em.
Given that I tend to get a fair bit less velocity than Nosler shows in their data with the same loads, I'm going to guess you get a LOT less speed than Nosler in your Mauser M18.
Is that so? So far I've tried two of your loads and my rifle is clearly generating a lot more pressure (or that Hart barrel has some crazy mojo to it).

Cheers, and heads up to others, start low, work up!

Rex

Hi Rex,

Know there are least two differences in your test than my results. First would be OAL: I used 3.365 and you used 3.375, which isn't much, but longer seating results in more pressure.

Second would be your batch of 8133. Despite the generally good job powder manufacturers do of keeping canister powders (the ones they sell to handloaders) within about 2-3% of previous lots, they can vary more--especially newer powders, where previous batches of slower or faster-burning powder aren't as common to mix with new lots, to "adjust" burn-rate.

Would also suspect that your Hart barrel has a tighter bore than the factory barrel on my Mauser M18. The head guy at a major pressure lab once told me that he's found .0001 inch of bore diameter, in most modern bolt-action cartridges, results in around 1000 PSI difference in pressure, give or take a little.

Also dunno what kind of shape your rifle's chamber throat is in, but after almost 30 years it may have some rough "gator-skin" erosion--which tends to increase pressure--until the erosion lengthens the throat considerably. It might also have a tighter chamber.

Dunno if you used the same brass and primer I did, but even if you also used F215s, they can vary some from lot to lot.

All of which is why I advise loading to velocity, not the powder charge.

John,
Thanks so much for your reply.
So, does your rifle produced a lot less velocity for the specified powder charge than Nosler shows in their latest guide, #8? Mine sure does.
Nosler got 3046 fps with the 160 grain and 61.5 RE-19. (Nosler case, Fed 215). Mine gives 2893 fps with the same load (WW Case, Fed 215).
Nosler got 3058 fps with the 160 grain and 63 RE-22 - mine got 3003 with the same (much closer to their spec)
I tend to think your idea of powder lot variations may be the main reason for the differences I've seen between your Handloader #327 loads and the two of them I've tried. Since I got much higher velocity than you with two different bullet/powders (160 AB/IMR 8133 and 175 ABLR/Magnum), when my "paradigm" is getting less than published, I figured maybe there were other factors involved. At least three things I would guess should be expected to get me LESS velocity than you, if everything else was equal. These are "noise level" differences but all finite and cumulative.
1) your barrel is 0.4" longer than mine.
2) you're measuring at the muzzle with your Lab Radar. I'm measuring 5 yards downrange with a 35P.
3) I am seated the same distance off the lands as you were (.025") but that results in my ammo being .010" longer than yours, which makes me think I have a throat that much longer and thus equal "jump" between our loads would indicate a little more case volume in mine.

We're using the same primers, Fed 215, but my brass is older but once fired Winchester (W-W Super headstamp). I prepped 50 rounds and found them very consistent. they averaged 229.5 +/- 1.0 grains. If your Hornady brass was a lot lighter than that, there could be another of the factors. Do you have the weight of those cases?

Despite being almost 30 years old, I've actually shot this 7 Mag very little. I killed a couple mule deer with it soon after getting it, but then got a bad case of Rifle Loonyism and started acquiring other rifles, and the 7Mag sat semi-retired until this year. Its throat is in great shape - no erosion there.

And your final statement above makes me want to get a confirmation from you:
"All of which is why I advise loading to velocity, not the powder charge."
RE: Nosler's top load with the 160 AB and 61.5 gr/RE-19 at 3046 fps.
I am up to 63 gr/RE-19 and still only getting 2979 fps. I reckon you'd say keep going to that velocity? If I was getting the accuracy I wanted at 2979 I'd be happy, but would like to see what it does closer to the same pressure Nosler used, since their fastest load with RE-19 was the most accurate.

Thanks again for your advice and time.
Rex

Interesting. At 64, I've re-started my use of the 7mm Rem Mag, after a ten year layoff from that cartridge.

Why? Simply because I found a rifle that I really liked (a 20 year old Ruger Number One S), and it happened to be chambered for a cartridge that I find very acceptable.

Regards, Guy

Rex,

"And your final statement above makes me want to get a confirmation from you:
"All of which is why I advise loading to velocity, not the powder charge."
RE: Nosler's top load with the 160 AB and 61.5 gr/RE-19 at 3046 fps.
I am up to 63 gr/RE-19 and still only getting 2979 fps. I reckon you'd say keep going to that velocity? If I was getting the accuracy I wanted at 2979 I'd be happy, but would like to see what it does closer to the same pressure Nosler used, since their fastest load with RE-19 was the most accurate."

You statement assumes that a few more fps are always better--though that can vary some with RL-19 in different temperatures (which can also affect accuracy).I have yet to see any notieceable difference in "killing power" from a 160-grain 7mm bullet started 100 fps faster--or slower.

If you want to work up a load that's (at least theoretically) the same pressure as Nosler's data suggests,then fine, work up to 3046 fps (or whatever the equivalent is with your chronograph). But even for a rifle loony you're being pretty finicky.

Ruger No.1B, 63

Ha! Thanks John. Do I get a prize or something ;o)?
Actually my main purpose in this (and my previous post re: 175 ABLR/Magnum) was to let folks know to be sure to do the standard wise thing and start low to work up with the loads you provided in your latest, since I found (for once!) that my M98 hits your velocities at significantly less powder than your M18 did.
I'm looking forward to getting back to the range with the 160 Accubond and something more down around 72 grains of 8133, which in mine I expect will do about 3000 fps (your magic number from "Handloads That Work").

One last try: Does your M18 get a lot less velocity with the loads in the Nosler #8 manual than Nosler's test rifle got?

Cheers,
Rex

I thought that was obvious. The velocities also varied some from the data in other manuals as well.

I have had a couple 7Rem Mags.Then I got religion and had a 280AI made.76 years young.