.280 Rem vs 7RM comparison...

22 June 2009, 18:52

TomP

quote:
Originally posted by rolltop:
quote:
Originally posted by enfieldspares:
I think that it is worth considering ammunition availability. I'd take a 280 Rem over a 7mm Mag ANY day...except when I left my ammunition at home! Then I know which I find easier to obtain.

This is a very good and valid arguement.

However I've never in my life left ammo home or lost it or remotely come close to needing to buy ammo on a hunt!

Me either, but the airlines want ammunition packed separate from the firearm, and you can't have either one in the cabin. They're pretty good with baggage, but you never know. I went on an elk hunt once with a fellow from Philadelphia, his rifle arrived on the last day of a ten-day hunt.

If the muzzle velocity is close, how can the recoil differ much, between the two?

23 June 2009, 03:42

fredj338

quote:
Originally posted by Big Bore Boar Hunter:
Its amazing how people say the magnum is set for the heavy bullets and long range. Lets look at data.

280 Reming Barnes TSX 175 gr 2,636 FPS

7mm Rem Mag Barnes TSX 175 gr TSX 2,757 FPS.

(loads taken from Barnes reloading manual #4 both using 24" bbl)

Thats a whopping 125 fps. At 400 yds (200 yd zero), thats a 2" difference on a 2.5 foot drop

Those be the facts. Yes, the 7mm Mag is immensely popular, mostly due to its introduction in the magnumitus boom of the 60's

And for those that doubt the WBY mag, it throws that same 175 gr bullet out at 3000 FPS. And no, the WBY is not the penultimate, but in my opinion, is the next step after the 280 if you want the noise and recoil, you might as well get something for it.

If you want 7 mag performance with 150 gr bullets, and want abundant factory ammo, look seriously at a 270 win.

You have to push the 280 pretty hard to get 2650fps w/ a 175gr bullet. It's pretty easy to get 2900fps w/ 175gr bullets in most 7rm, especially in 24"-26"bbls of most magnums. I agree though, there stil isn't much diff. in traj. out to 400yds.

23 June 2009, 04:24

mikethebear

With my 7mm-08 and 175 grain bullets I was able to get 2475fps out of a 20 inch barrel. About 1/2 grain less than max of H4350. I would think that a 280 would do much better if loaded to 270 win pressures.

23 June 2009, 07:52

Big Bore Boar Hunter

quote:
Originally posted by fredj338:
quote:
Originally posted by Big Bore Boar Hunter:
Its amazing how people say the magnum is set for the heavy bullets and long range. Lets look at data.

280 Reming Barnes TSX 175 gr 2,636 FPS

7mm Rem Mag Barnes TSX 175 gr TSX 2,757 FPS.

(loads taken from Barnes reloading manual #4 both using 24" bbl)

Thats a whopping 125 fps. At 400 yds (200 yd zero), thats a 2" difference on a 2.5 foot drop

Those be the facts. Yes, the 7mm Mag is immensely popular, mostly due to its introduction in the magnumitus boom of the 60's

And for those that doubt the WBY mag, it throws that same 175 gr bullet out at 3000 FPS. And no, the WBY is not the penultimate, but in my opinion, is the next step after the 280 if you want the noise and recoil, you might as well get something for it.

If you want 7 mag performance with 150 gr bullets, and want abundant factory ammo, look seriously at a 270 win.

You have to push the 280 pretty hard to get 2650fps w/ a 175gr bullet. It's pretty easy to get 2900fps w/ 175gr bullets in most 7rm, especially in 24"-26"bbls of most magnums. I agree though, there stil isn't much diff. in traj. out to 400yds.

Again, these are max loads, max SAMMI, max velocity loads as listed in Barnes reloading manual, I have heard of people loading a 180gr 30-06 to 3400 fps, just don't get many shots off. I used that manual because both were tested in 24" bbl lengths to compare apples to apples. Sammi max for 7 Mag is 61000 PSI and 280 rem 60000 psi.

Again, it is all academic, either will do the job, but I still chuckle when I hear of the "magnum advantage" in long range shooting. To best the 270 or the 280 you need to skip 7mm Rem Mag and go to 7mm Weatherby or better. To go back to the original question, ther eis very little advantage ballistically between the 2. Although, as stated, the availability of ammo is a plus for the 7 Rem Mag, but a 270 would be a better choice if availability is an issue.

John

23 June 2009, 20:50

akrange

I don't shoot the 175 gr. .284 bullet in my 7mm Rem Mag.I shoot the 160.. After looking at my load and the top load in the .280 Rem for a 160 bullet I find that at 400 yrds I'm -8 inch's low with a Ton of energy on demand.. I don't load for the .280 Rem so I have to use the book and appears with it's Load/MAX Velocity at 400 yrd's it's -13 inch's low and it's retained energy.. Well maybe John can help us out there...
AK

23 June 2009, 21:34

SIR MAUSER

akrange, how high are you zeroed at 100 yards to be 8" low at 400?

24 June 2009, 00:00

taylorce1

quote:
Originally posted by SIR MAUSER:
akrange, how high are you zeroed at 100 yards to be 8" low at 400?

You would have to be right around +4.5" at 100 to be -8" at 400 with a 160 grain bullet going 2900 fps. That would put your zero at 325 yards. Of course I don't know the speeds of his loads, so I used an average for a factory load.

24 June 2009, 00:47

SIR MAUSER

Thanks taylorce1.

24 June 2009, 01:30

akrange

I'm 3 inchs High @100.. MV 3140... IMR 4831 and H-1000 will get you there...
AK

24 June 2009, 01:38

SST

With 140gr bullets, it really doesn't matter what 7mm cartridge you use. They will all kill medium size game as dead as dead can be. If you want to shoot heavier bullets in 7mm or shoot more than 300 yards out, go with the 7mmRemMag.

24 June 2009, 03:37

Big Bore Boar Hunter

quote:
Originally posted by akrange:
I'm 3 inchs High @100.. MV 3140... IMR 4831 and H-1000 will get you there...
AK

What bullet are you using to get that trajectory? BC would be bettr than .500 which is stellar for any type of hunting bullet. Sounds like you are using a 26" bbl as well, thats good for about an extra 50-100 fps. 3100 fps of 160 gr was norm in the 70's and 80's, once saami starting listing PSI instead of CUP velocities dropped significantly for max in the 7 Rem Mag.

24 June 2009, 03:45

Big Bore Boar Hunter

quote:
Originally posted by akrange:
I don't shoot the 175 gr. .284 bullet in my 7mm Rem Mag.I shoot the 160.. After looking at my load and the top load in the .280 Rem for a 160 bullet I find that at 400 yrds I'm -8 inch's low with a Ton of energy on demand.. I don't load for the .280 Rem so I have to use the book and appears with it's Load/MAX Velocity at 400 yrd's it's -13 inch's low and it's retained energy.. Well maybe John can help us out there...
AK

Again, quoting from Barnes # 4

280 Remington using 160gr TSX 58.5 gr Mag Pro 2,744 fps. 200 yd zero, -26.3" at 400 yds

7 Rem Mag using 160 gr TSX 63.0 gr RL25 2,856 fps. 200 yd zero, -24.3: at 400 yds.

160 gr TSX has a BC of .392.

Again, this is apples to apples. Barnes shows both as 24" barrels. TSX bullets seem to be shot at lower velocities (develop higher pressures?) than other bullets, so it is possible to get more velocity out of them, but this is one bullet to the same bullet in same barrel lengths. This is not to say the 7mm Mag isn't a good cartridge, just that its ballistic advantage over the 280 rem or 270 win is greatly overplayed.

John