I'm considering a 7mm rifle and need some information about the 7mm RM and the 7mm Weahterby. From the drawings in my manual, the cases look like they are nearly the same size. How many grains of wter will each case hold? Do most loads for the 7mm Rem Mag fill the case or do you reach max pressure before you get high load density?

How much of the Weatherby's velocity advantage is due to the 26" barrel? What kind of velocity do you get out of a 7mm Rem Mag in a 26" barrel (without exceeding the max loads listed in the manual). Are they loaded to the same pressure (52000 cup vs 65,00 psi)? I would think that it would not be a problem to load the 7mm Rem Mag a little bit hotter than shown; the 25-06 is loaded to 53,000 CUP. I should be able to reach that pressure safely (I realize I'll have to work up slowly etc..).

In a 7mm RM, you should be able to safely get 3150-3200 out of a 26" barrel and a 160 gr. partition. The charges of the slower powders (RL 25 and Retumbo) just fill the case. You will not totally fill the case with RL 22 and 7828.

The Remington 7mmMag is loaded to 52,000CUP
The 7mm Weatherby is (according to Norma) loaded to 55,100psi

Once you factor in conversion from CUP to PSI the difference isn't great.

It looks like the weatherby is good for 50-125fps and that is dependant on specific bullet weights. and that's out of the Speer manual.

Some loading manuals (nosler) show less gains.

7mm Rem brass is cheap and plentiful...

AllanD

The Speer manual shows the & Weatherby at 65000 psi. I'll bet the 55,000 number is CUP.

The 7MM mag is much easier to find components for I'm guessing it should nearly match the Weatherby when loaded to similar pressure in a 26" barrel.

I have both and I have never had a problem finding cheap once fired .300 Win. Mag. brass that with a bit of work turn it into 7MM Remington or Weatherby brass. Outside of that the rest of the reloading componits cost the same except for powder amounts. I can easily get 175 fps. more from my Weatherby. The real issue is finding factory ammo for the Weatherby in small, out of the way areas. Then the Remington gets te nod. Lawdog

I just looked both up in Quickload's database.

7mm Wby 7mm Rem Mag
87gr............82gr..........Case capacity (gr of water)
63817 psi.......62366 psi.....Max Pressure - both same method (Piezo CIP)

The max pressure is almost the same, but the case capacity of the WBY is a bit larger. That plus the long Weatherby freebore which has the effect of making the case capacity "seem" larger than it actually is. No significant resistance to the forward movement of the bullet until it hits the rifling (much greater distance in the Wby) should lower the peak pressure for a given powder charge/bullet combo. Quickload does not take the freebore length into account in it's calculations.

Bob Hagel shot the 7mm Mashburn Super with 175 gr Partitions. Hagel is pretty much the expert on long range Western hunting.

Those cartridges are just fine but not the only ones. If your rifle is going to be full size anyway there are the 7mm STW and 7mm RUM. I would rather carry one of these than a long 26" barrel.

Most 7mm STW's come with 26" barrels. With a 24" barrel I doubt you'd know the difference between a standard magnum and the STW. There's only 200 fps seperating the two. Barrel length probably accounts for 50-150 fps.

The 7mm RUM is very inefficient. 23 grains more powder for a 300 fps increase? Thats a lot of wasted powder, recoil, and barrel wear for very little gain. The 7mm Weahterby equals the RUM's performance and is much more efficient.

quote:

The 7mm Weahterby equals the RUM's performance and is much more efficient.

I have chronographed at least a half dozen 7mmremmags, a couple of 7mmwby mags,four 7mmstw's and two 7mmRUM's.The wby mag only adds about 75fps over the 7mmremmag.The 7mmstw will add another 100fps to 125fps or so over the 7mmwby and the 7mmRUM another 50fps to 75fps over the 7mmstw.

What velocity were you seeing from the 7 RUM with a 160 gr bullet? Was it higher than the 3300 shown in my loading manual? Hornady got the same velocity from the Weahterby. I admit that I'm going oof of the laoding manual and not off actual chrono readings, so I'd like to hear the real world velocities you're seeing.

That being said, I'm really not interested in the fastest 7mm on the planet. I'd settle for 3200 fps from a 154 gr bullet.

quote:

I admit that I'm going oof of the laoding manual and not off actual chrono readings, so I'd like to hear the real world velocities you're seeing.

My numbers are all chronographed.

140gr bullets-7mmremmag-3250fps to 3300fps
7mmwby-3300fps to 3350fps
7mmstw-3450fps to 3530fps
7mmrum-3575fps

160gr bullets-7mmremmag- 3050fps to 3100fps
7mmwby- 3150fps
7mmstw- 3275fps to 3300fps
7mmrum-3330fps

What length barrel?

Unless you are talking semi custom, your choice really comes down to which rifle you want to shoot. The Wby. does hold more powder, sort of a 7RM impr. You will get about 100fps more vel. assuming same bbl. length. You will be pushing the 7RM hard to get 3150fps w/ a 160gr bullet. The Wby. will get you there w/ a bit less pressure. The 7mm Dakota is another thought on the same length action. You can get about 100fps over the 7mmWby., about what you get out of a 7mmSTW in a std. lenght action. I have a 26"bbl. #1 in 7mm Dakota (used to be 7mRM) & I get an eay 3250fps w/ 160grNP over RL22 or IMR7828. When it was a 7mmRM, vel. ran 3100fps+ for the same bullet. I think the 7mmRUM is way overbore, too much powder for little gain over a 7STW or the Dakota.

Fredj338,

Have you tried RL 25 or Retumbo im a 7RM yet?

quote:

What length barrel?

For the 7mmremmag,both 24" and 26".For the wby, stw and rum all were 26"

I have a 7 RM w/ a 24" tube and a 7 WM w/ 26" tube. The 7WM is usually 150 fps faster than the RM w/ max loads.

My 7WM shoots 140 Barnes TSs @ 3390 15' from the muzzle w/ 2 grains below listed max (IMR7828). The 7 RM will not get even close to that velocity, even w/ max loads.

If you reload your ammo the only cost factor is brass and the extra 6-8 grains of powder. I have been able find the 7WM brass on the net for about the same price as 7RM brass (EBAY and other Sources).

The 7 Rem Mag will be much easier to find brass for in remote areas.

If 75 to 150 fps doesn't make that much of a difference to you, I'd definitely go the 7 Rem Mag route.

As to recoil, the 7 RM kicks less, at least w/ these two rigs even though the Weatherby is heavier.

Good Luck!

Reloader

The 7mm weatherby offers so little advantage that it's not worth the higher cost of components and ammo. On the other hand if you're a reloader you should be able to almost erase that extra cost and earn yourself 150fps extra or so.

If you're really concerned with earning a serious ballistic advantage in a 7mm caliber rifle, go with a 7mm STW (shooting times westerner). The brass and rifles are more scarce than the Weatherby, but if you reload this should be a minor problem. It holds more powder than either the rem mag or the weatherby and with slower burning powders you could really add a serious ballstic advantage over the other two calibers.

quote:

Originally posted by Reloader:
I have been able find the 7WM brass on the net for about the same price as 7RM brass (EBAY and other Sources).

Reloader

I guess you are one of the ones I am always having to out bid on Ebay?

Lawdog

FWIW, My 7mmRM w/ 24" tube gets 3150 fps with a stout load of RL22 behind a 139 gr. Hornady. It must be a slow one! However, a 7mmSTW I recently shot extensively, would go 3400 fps with 140's, also w/ a 24" tube. I have two 7mmSTW's ratholed, both w/ 26" bbls., which I haven't got around to shooting yet, but I have high expectations for these! I have no plans for a 7mmRUM, it is, as others have pointed out, far too overbore, and this is coming from a confirmed 264WM shooter! My 7mmRM is a killing machine out to as far as I could possibly hold, so I don't know what I need to shoot 7mmSTW's for, but what the hay, I'm having fun! I will have a 7mmWSM on line shortly (I have everything, rifle, scope, rings, dies, etc.), just need the time to get everything screwed together and load development started. Do I expect this WSM to outperform my 7mmRM? No!! I expect it to be the ballistic equal to a 7mmRM, no more, no less. Just in a short action with that short fat case. But I guess I just like 7mm's! Another variation can't hurt. And no, my 7mmRM is NOT for sale! Carry on!

Stud,

It is reasonable to think you would get as much as another 100 fps (or the same fps with 20 gr. more bullet weght) with 2 more inches of barrel and a touch slower powder.

Where in Dakota?

No Soda, I rechambered before RL25 or Retumbo were out. I should give RL25 a ride in my Dakota & see how she bucks. I can get 3300fps w/ a 160grNP but it's a warm load, fine for winter use, I just back off 1gr to 3250fps ofr an allround perf. using 72.5gr RL22 or 73.5gr IMR7828. Very flat shooting out to 400yds, about as far as I need or want to shoot. I still think you have to push the 7RM to get 3200fps even in a 26"bll. but if you have actually chronographed loads there, good going, just not my exp. The 7Wby would be a bit faster w/ any load over the 7RM.

The slower powders seem to wring the last little bit out of a 26" barrel.

3200 would be what I would expect from exceeding the max loads slightly to reach 65,000 as originally posted.

I am averaging 3150-3175 with book loads and a 25.5 inch barrel.

The max load listed for Retumbo is at a low pressure because Hogdon lists it as compressed.

A fire formed case will take a little more powder and with a long barrel.....

This should be perfect for your larger cases.

Accuracy is exceptional.

quote:

I guess you are one of the ones I am always having to out bid on Ebay?

Lawdog

No, not me but, I know what ya mean. It seems like some folks get a little carried away and end up paying almost new prices for the used components on Ebay.

I got my last supply of 7 Weatherby brass from a place in Alabama and I'm currently working on a deal w/ a gun shop in Utah.

If I find any great deals, I'll be sure to let you fellas know.


Good Luck!

Reloader

Fred338, I have no problem getting 3250-3300 chrono'd w/140gr bullets in my 7mm RM. I have a 25" bbl.Powders are H4831 and RL 22

You are right Rob, but soda is getting this w/ 160gr pills. 3200-3300fps is easy in most 7RMs even w/ a 24" bbl.

Sodakhntr,

Minot. You?

Watertown

I'll tell you what, the Weatherby Ultra light chambered in 7mm Weatherby mag would be an awesome tool. I had one in 300 Weatherby but the recoil was to stiff so I sold it. I'd love to have another in either a 7mm or 270 Weatherby. Their expensive, but well worth the money. The 300 I had was very accurate and light. It weighed 8lbs. with a Leupold 3x9 scope attached. A 7mm mag in either flavor would have been much more pleasant to shoot than the 300!