Home Forums Hunting & Shooting Ask The Gunwriters 7mm Rem Mag and Hodgdon's data

M D -

W/O deleting so much to quote you, let me do this:


Mule Deer:
"The mil-surp powder ran out in the mid-1970's, so Hodgdon started having a similar powder made in Scotland, also called H4831. This version was reportedly a little "hotter" (faster-burning) than the original mil-surp stuff. I don't really know if it was hotter,.... "

I STILL have most of a pound made in 1981 from Scotland. I HAD to REDUCE the charge by 2 grains to stay close to the Surplus.

Mule Deer:

"considerably "hotter" than my present batch of Australian Extreme powder. I shot some of both in my present .270, using 130-grain Hornady Spire Points, Winchester cases and Winchester Large Rifle primers, all from the same lots, and 61.0 grains of mil-surp powder resulted in almost 100 fps more velocity than 61.0 grains of Extreme H4831."

Yes - indeed Surplus AND H 4831 (newly manuf) have VARIED considerably. Hence I simply quit using it. IMR 7828 is slow enuff to give +/- 3100 fps and NOT blow primers.

I can't verify these thing on the net....

but if anyone want to come by, we WILL graph diff lots.

Jerry

If you look at the 139 jacketed chart.
I HAVE 1 700 RM that loves 68 gr IMR 4350.

I have 'another' 700 that 67 gr = the other rifle in vel & accuracy.

I also have (1 has passed) 4 friends with 700s and their rifles ALSO tapped out at 67 grs.


I and WE have USED these loads for years. I have ammo loaded TODAY w/ 67 gr IMR 4350, 139 HBTSP = [3300] FPS .


Maybe that scares 'some' but I/we have shot 100s of rounds w/o blowing primers AND good accuracy.

Jerry

Rob,

I have the Sierra 5th edition manual and it shows 63.6 grains of H4831sc @3000 fps as the max load for that bullet in the 7mm RM. I would agree with the folks who replied that your load is probably fine.

I have been using the Hodgdon online data more lately because I am transitioning to their newer powders specifically IMR4451 & IMR7977. I have also noticed some strange looking data there.

They show the 270 Win getting 2940fps with a 150gr Hndy SP & 60.8 grains of 7977, while the 7mm RM with a 150gr Partition gets only 3042 with 70.9 grains of the same powder. That is 10 extra grains of powder for a 100fps increase in velocity. doesn't make much of a case for the 7mm.

My copy of Nosler #6 shows the big 7 getting well over 3200fps with 150 grain bullets & both IMR 4350 & 4831.

I don't own a 7mm RM so I haven't tried any of those loads, but I do have a pound of 7977 that I am going to try with 150s in my 270.

Bob

General Comment: It's one thing to look at the books for 270 velocities and compare them to 7 Rem Mag; it's another thing entirely to get those velocities.

And that can be as true for the 7RM as the 270. So looking at single data sources and saying ......."Oh look the 270 gets 2940 and the 7 RM gets 3040...not so hot" is easy to do.

But when the 270 only chirps off 2840 at the range and the owner says "WTF"? and the 7 RM (owing greater powder capacity) gets the same 150 to 3140 or so the differences become more apparent.They were never "huge" to begin with....

Point being....day in and day out, rifle to rifle the case with the larger capacity will win the velocity race and if it doesn't something, somewhere, is not equal.That simply will never change.

And of course there are the 160-162 gr bullets in the 7 RM at 3050 or so; and the 175 at over 2900 fps. No 270 loads can touch that. That's a 175 gr bullet at the same velocity a 270 gives a 150.

It's maybe best to think of the 7RM as picking up in bullet weight and velocity where the 270 leaves off. If you aren't realizing that potential that's your fault.

Show me what the rifle does in real life...not just in manuals.

10 gr more powder? Of course! That's how it gets more velocity!

I've never dropped a bull elk on a distant ridge with a 7 Rem Mag and said to myself..."Gee....I wish I had done that with 10 gr less powder.

Who thinks that way?

But hand loaders think that way because their perspective gets skewed by nutty theories like "efficiency" while leaving performance on the table...which is just another way of saying...I lost 200 fps but I did it with 10-12 gr less powder. Whoopee!

That is SSOO low on my list of important shidt I don't even think about it.

Not an improvement?

I dunno......

Bob -

Yeah, we've got a few here on the C F who think likes this:


Bob's Post Above:

"I've never dropped a bull elk on a distant ridge with a 7 Rem Mag and said to myself..."Gee....I wish I had done that with 10 gr less powder. frown

Who thinks that way?"
----------------------

Efficiency is great but it's 'usually' at the expense of performance.

I just bought a 'new to me' 4X4 Full Size truck. I've had 2 small trucks. 1 a GMC Sonoma & 2. a Ford Ranger Edge.
I thoroughly enjoyed having even 4x4 transportation at greater MPG. BUT...

The smaller trucks can't haul, pull, & STOP the load of a Full Size truck.

Performance comes AT a Price---trucks/rifles.

Jerry

When you're driving 300 miles a day, a more efficient vehicle that still gets you from A to B starts to make a lot of sense. The big 4x4 comes in handy when pulling a trailer in a blizzard.

Trucks/rifles.

Case capacity has its place, and I'm no detractor of the 7RM, 7WSM, and the like, but some guys like to practice and shoot more than a little, and 10-12gr per shot adds up to a fair bit more practice per $. It's not just the 10gr difference during the kill shot, but the thousands of shots taken during practice sessions that matter. It's easy to add a couple of extra Mils to the elevation dial, and 40gr of powder pushing a 162 at 2700fps compared to 68gr pushing the same bullet at 3080fps equates to a bunch more trigger time learning the wind and getting rock-solid dope, per pound of powder. There are times/places for performance at all costs, and others where efficiency leads to better outcomes.

I find this entertaining. I was sitting on ridges in both Colorado and Wyoming this year elk hunting thinking if I only had a rifle capable of shooting 10 grains more bullet with the same BC, with 10 grains more powder to arrive at the same velocity - I could really kill an elk!

I bet both elk I shot are really pissed that they died from a bullet weighing 10 grains less and shot with 10 grains less powder. Maybe I could get a rifle that weighs an extra pound to get the same level of recoil.......

Jordan: I got more than one rifle,chambered for different cartridges.

Some have lots of capacity,and some not so much.

Bob,

I'm wasn't trying to say anything about efficiency or that the 270 can keep up with the 7rm with the same weight bullets. Physics being what it is, more powder capacity should equal more velocity. My comment was aimed more at the data. If you read my post you can see that I quoted Nosler #6 data showing 3200+ with 2 powders for the 7rm with 150s. In fact Nosler #6 lists 5 powders that will get you over 3100fps with a 150 in the 7RM. I freely acknowledge the ballistic superiority of the big 7.

I guess what I was trying to say is, doesn't someone at Hodgdon look at this data and say, why is it that our data says that the 270 win gets almost as much velocity with a 150 grain bullet as the 7mm RM and with 10 grains less powder? That can't be right, can it? Even though the 7 is handicapped by a lower map it should still beat the crap out of a 270.

What it boils down to is that my 10 year old printed loading manuals are obsolete. IMR4350 and IMR4831 powders are on the way out. I am trying to get a handle on the new products, that is why I am looking to the website for information, and it is hard not to notice some discrepancies.

Bob

I have never used anymore than 65 grains of IMR 4350 with a 140 gr. Bullet in my 7 mags. Mostly use 64 for years.

Bob,

Exactly. You get where I was going with that...

Here is a point I believe is involved in the new load data. If the powder company pressure tests a load at 60,000PSI with 66gr H4831 and a 160gr bullet. The data books that do not list pressures are likely using a standard 5% reduction on the max powder charge to take into account lot to lot variation. A very good reason to use the latest Lyman data book and the bullets they tested. Just look at the Quick loads software data. It uses 10% as a baseline.

Yep, Jordan, there is a time and place for everything.

I reckon the difference with me is, I've already DONE the loading, graphing, practice for many years. I've already paid the $$$.

For many yrs. guns, rifles & handguns, loading, graphing, experimenting, practice & hunting WAS/WERE my ONLY hobbies.

I did not fish, golf, or many other things. There is NO telling how many lbs. of powder, bricks of primers & bullets
that I shot. So I have B T D T.

I have determined what performance please me. Recoil is not a hindrance or deterrent for me.

So when it comes to hunting rifles- I don't run hundreds of miles burning more fuel - if you get my drift.

Jerry

Jerry,

I'm right there with you, but marksmanship is a perishable skill, and the only way to be truly proficient with a given rifle and load is to keep on amassing spent primers with said rifle...

Yup!

Thanks to everyone for their reply. I'm going to shoot sparingly the remaining supply of loaded cartridges containing my original load of 65 grains of H 4831 and 160 grain Sierra spitzers made from my old can of
H 4831. When that can is used up and replaced with a recent manufactured lot of H 4831, I'll switch to the new revised loading data. Thanks again for the replies to my query.

I find the recoil argument a bit interesting as well.

I freely admit to being purulent (look it up ) but recoil from a lightweight 7 mag is objectionable to me. Lets assume Kimber MT - one in 270, one in 7RM, both weigh 6.5lbs.

My current 270 load, 150 gr bullet, 60 grains Re 26, 3040 ft/sec = 29.5 ft/lbs moving 16.3 ft/sec

My former 7RM load (26" brl), 160 gr bullet, 70 grains H1000, 3050 ft/sec = 36.2 ft/lbs moving 18.0 ft/sec

Different calculators will yield different absolute numbers but the magnitude between them is the same. You get ~ 25% more recoil with the 7 RM over the 270 - for what gain? 10 grains more bullet weight? You have to add 1 lb of rifle weight to get the same level of recoil. The recoil numbers don't actually tell the whole story. To me the recoil velocity is the difference. I find anything moving much over 16 ft/sec to feel like a punch to the shoulder. Recoil velocity is why heavy rifles feel more like a push then a punch. The recoil energy is still there but its not coming back at you as fast.

I took a beating for bringing this up in September but physics is physics. The 7RM doesn't shoot any flatter and bullets don't arrive with more velocity. If you believe kinetic energy, the 7 RM does land with 1-200 more ft/lbs. If you want to run one of the bigger 7 mags, yeah the 270 can't run with it - but we could have a long discussion about performance, rifle platforms, hunt objectives, and various tradeoffs. I'd submit with todays bullets/powders in smaller cartridges in lighter rifles cover more ground than rifles/bullets/powders of 30-40 years ago - mainly because rifles are lighter and smaller cartridges don't recoil as much. As Jordan pointed out, people shoot lighter recoiling cartridges more leading to better shooters.

The 270 Kimber Montana with Re 26 and 150 grain bullets leaves nothing on the table compared to the 7 RM. It is a very good mountain rifle.

Flame suit on.

If you're going to be buying new powder, you would do yourself well to look at a couple of the new numbers, such as Reloader 26.

As to the 7RM, I've yet to hear of anybody having any actual problem when loading it the max or not. Much ado about nothing, since there is so much safety factor already built into the data, including the old stuff. Nobody has been blowing themselves up since back in Elmer Keith's day.

I'm with you and Bob on this one - I've run 2-4 grains over the 58-60k psi max loads for years in 4-5, 7 RM without issue. The only issue I ever had was with 140 TSX when they first came out. It turns out my 7RM at the time had a min spec chamber. Book max of IMR 4831 ran 3300+ in my rifle - and tight extraction, cratered primers, etc. I only shot 2 to figure that out.

In my 24" barrel 7RM, I ran them routinely to 3200 with 140's, 3000 with 160's and 2900 with 175's. Use one of the slower powders, keep to those vels and there shouldn't be an issue. You may be able to run them slightly faster but I didn't and still don't think the extra 50 ft/sec is worth risking running the redline on a known problem with the 7RM, even though I've never witnessed it or was aware of it if it did happen.

Well....who builds 6.5pound 7 mags? Thats too light.

I need to try something else in the 270.....despite a few thousand rounds of both I have never been able to get any bullet from a 270, to stay with a 7 mag and bullets from 140-160 gr to 600 yards.



The 7 mag loads behave like a 300 magnum.