I just came from another website where an individual is trying to convince everyone that the 7mmwby mag produces over 300fps more than the 7mmremmag and produces within 50fps of the 7mmultramag all with 26" barrels.He claims that the factory 7mmwby rifle in question produces 3450fps with 140gr bullets and that he has actually increased the powder charge 3 grains more without pressure signs but accuracy goes away at that point.What do you think-fact or fiction?

Stubble
paste this between the image signs for a photo and send it to him....

http://img92.exs.cx/img92/6236/bush1.gif

It wouldn't hurt to add a few smiley faces.....

I'd have to go with fiction, or dangerously overpressure handloads, Stubble. I've owned a 7 Rem mag, Wby and STW and while the Wby was faster then the Rem, it wasn't by much, and nowhere near the speed of the STW, never mind a RUM. - dan

Fiction. A 7mm Roy is faster that a 7mm Rem Mag but not enough to really matter as previously stated. As "Cartridges of the World", 9th ed. sums the difference up well..."Bitter arguments will ensue as to which is best or most powerful. This will be akin to the ancient Greek pastime of discussing how many spirits can dance on the head of a pin."

IMHO, 140s belong in 7x57s, 7-08s or 280s, a 7 mag is at it's best with heavier-for-caliber bullets (at least 160gr), giving more momentum, better penetration and less blood shot meat. I have a 7mm RM and feed it 175gr fodder (Interlock's for whitetails, Partitions for tougher game).

He is probably "guestimating" his vel. I can just get to 3400fps from my 26"bbl. Dakota w/ 140gr. I'll agree w/ BH though, the real benefit to the big cased 7s is pushing 160-175gr bullets @ greater speed.

Fiction ----- I have shot them all extensively and agree with Dan. He is probably like one of those hunters that guestimates everything like Deer weights and distances of shots then writes it as the truth. He also could be reading the Barnes misprinted pages in their blue book. Good shooting.

Gentlemen



I had 7mm rem mag and 7mm wby, a new 7mm wby is on it's way . My experience is that with the Weatherby there is a 100 fps difference with 150-175 grains bullets(26 inch barrel)at the cost of 2-3 grains more powder compared to 7mm remington. I like the wby because it has longer neck and bullets doesn't have to be seated deeply in the boiler room.



A 7mm wby with 160 grain partition will do 3200 fps, a 7mm STW will offer approximately 100 fps more (from 26 inch barrel). This new Ultra mag might offer a bit more horsepower. The cost of more performance is heavier recoil, more powder and shorter barrel life. Shooting hunting rifles weighing 9-7,5 pounds in whizz bang calibers can be a problem, especially from field positions.



Out to 500 yards the difference is a few inches trajectory. Rangefinder is great help and will avoid any guess work. Seriously, estimate wind is the biggest problem, a hard nut to crack



Cheers

/ JOHAN

Some almost facts mixed with a lot of fiction.

Lets check some of the manuals for top velocity in the 7 mm Wea with 140 gr bullets.
Nosler.................3340 w/ Rl22
Hogdgons...............3238 w/ IMR7828 (not a Hogdgon powder when this manual was written)
Hornady................3400 w/ seven different powders
Sierra.................3300 w/ nine differnt powders
Speer #10 circa 1980...3228 w/ IMR4831 & 145 gr bullet

These manuals show the max velocity for the 7 Rem Mag as virtually equivelent to the 7 Wea to as much as 200 fps slower.

While the loads mentioned in this other post are within the realm of possibility, they are definatly on the high pressure end of the spectrum.

Said other poster is also selling both of the Remington Mags far short of their potential. The capacity of the 7 Rem mag and the 7 Wea mag cases are so close that any difference is of no consequence. Anything that can be done in one case can be done with the other.

The loads for the 7 Wea have historically been listed as higher than the 7 Rem because of the freebore built into the throat of the Mk V rifle. This freebore allows the Mk V to digest a somewhat greater powder charge than a standard throated rifle, which in turn generates a somewhat incresed velocity without reaching dangerous pressures.

One need only have the throat of their 7 Rem mag adjusted to match the Mk V to make them equal. The difference is not in the cartridges but in the rifles which have been factory chambered for the cartridges. And the differences are not nearly as great as claimed by this other post.