7mm Rem Mag VS 7mm Rem Ultra Mag

[Long Time Long Ranger]

Sell the 7mm remington and buy two rifles. A 280 AI or 7mm wsm to replace your 7mm remington if you want a 7mm. They are better, more efficient cartridges that do basically the same thing performance wise. Then buy either a 300 RUM or a 338 RUM. Now you are equipted for anything that chalenges you. The 7mm remington is a cartridge out there in no mans land. The 280 AI and 7mm wsm do basically the same thing with less boom and recoil. If a guy wants a magnum 7mm they make a 7mm STW that will outperform the three previous mentioned. So it just leaves the 7mm remington in a bad place logically speaking. I own two and they get no use. If I want a cartridge in that class I always pick up my 280 AI. If I want a magnum I always pick up one of my 7mm STW's. If I want a big gun to kill big stuff way out there I pick up my 300 RUM or a big 338. So from a guy that has all of them that is my advice.

Not that the 7mm rem mag is a bad cartridge because it performs very well. It is just an inbetweener that doesn't have enough seperation from the 280 AI and wsm to make it worthwhile and is not a magnum like the STW which has quite a bit of seperation between the 280, wsm and rem mag.

The 7mm wby is a great cartridge in a Mk 5 rifle. It is faster than the rem mag but not equal to the RUM. The popularity of the wby's falters severely because of the price of brass however now remington and others make it cheaply. They may catch on again now but there are just so many new choices with beltless designs the wby's may have lost out to cheaper more popular choices. I have shot the 7mm wby quite a bit and have owned at least two since the 70's taking numerous animals with the cartridge. It is a very accurate cartridge.

 

[Bart B]

When the 7mm Rem Mag was popular for high power prone matches at 1000 yards, top shooters got about 800 to 900 rounds of best accuracy per barrel that started out shooting no worse than 7/10ths MOA at 1000. With the 7mm RUM burning near half again as much powder and shooting just as accurate, I predict its barrel life will be no more than 500 rounds.

 

[Long Time Long Ranger]

Bart, you predicted correctly. When we got the specs on the 300 RUM before it was released I did several rifles necking the 300 RUM to several calibers. I did two 7mm-300 RUM's which later became the 7mm RUM. Both had 31" Hart target barrels and were spectacular for accuracy and overall performance. By 400 rounds it was done and rebarreled to a better cartridge. I still have the other unfired since 1998.

 

[LouBoyd]

Whatever you pick make sure the rifle has a long enough magazine and a suitable twist rate for the bullets you want to shoot. Compare the case length, the cartridge SAAMI length, and the bullet seating depth you have to use to fit the magazine and throat.

The 7mm Rem Mag, 7mm Dakota, and 7mm Wby Mag all have fairly short cases, near 2.5 inches, To shoot heavy VLD bullets those can use a 3.6" magazine though it can still be tight. The 7mm STW and 7mm RUM have 2.85" cases and do not shoot 180 Berger well even in a 3.6" magazine. You can modify Rem 700 LA to get nearly 4" magazine space using Wyatts magazine mods. That takes a some gunsmithing but it's reasonable.

The required twist rate is a functon of velocity and air density. I shoot at a mile elevation in Arizona and twist is rarely a problem, but if you shoot near sea level in cold weather a 9" or longer twist may not work with heavy VLDs.

Check the terminal energy at the distance hope to shoot. Remember that energy is the square of velocity and drops rapidly with distance.

 

[Scratch]

I've been shooting the 7mm Rem Mag for 36 years (same rifle). The first barrel went over 2000 rounds before replacing it. I shot 68 grains of Imr- 4831 way above max today. When the group opened up to 1" at 100 yards I replaced it.
I now shoot a 26" Shilen
175 grain Nosler Partitions
66.0 grains Imr-7828
CCI-250
WW brass
3060' fps 15' from muzzle

All the power you need in NA animals, plus they don't know the difference if muzzle velocity is 3000 or 3200 fps.

Scratch

 

[Bart B]

I've been shooting the 7mm Rem Mag for 36 years (same rifle). The first barrel went over 2000 rounds before replacing it.

Did that barrel start out shooting no worse than 1/4 MOA at 100 yards and stay at that level of accuracy for 2000 rounds?

This is the criteria I've used for years as well as what my earlier comments on 7mm Rem. Mag. cartridge accuracy. If your barrel started out at no worse than 3/4 MOA at 100, then it may well have held that level for 2000 rounds.

Such cartridges have to shoot 1/4 MOA or better all the time at 100 yards to hold no worse than 7/10 MOA at 1000.

 

[lloydsmale]

please send me any of your 7mags that only shoot 1moa. Plenty good enough for this guy!

 

[mrultramag]

I'll be a dissenter here. My experience with my 7 ultra has been good. I'm well over 700 rds and it shoots as good as when new. I've not one instance of it misbehaving when reloading for it... its proven less finicky than many of my other cartridges I load for. I've not run 180's in it but have run 160's at an easy 3250, 150's at close to 3500, 140's at anywhere from 3400 to 3560. I dont shoot it more than 3 times with out cooling and clean every 20 rds or so. just like all my large capacity magnums. Use appropriate powders like retumbo, RE 25, IMR 7828 to name a few. keep loads towards max. Nothing wrong with the 7 mag. Just kinda tire of people on this board slammin 7 ultra....some who prob don't own one. Funny how reading a couple negative posts can become the gospel.

 

[Scratch]

mrultramag

I believe you hit the nail on the head with you're shooting style. I don't have a 7mm ultra but do have a 300 ultra. And I also don't shoot more than three times without a cool down and clean every twenty shots or less. My 300 is a tack driver straight out of the box with 180 SAF @3400.
I believe the 7 mm ultra is a outstanding long range caliber.

Good shooting!

Scratch

 

[Bart B]

And I also don't shoot more than three times without a cool down. . .

If your barrel won't shoot straight and true for 40 to 50 shots fired a minute or so apart as it gets way too hot to touch, your barrel is either improperly stress relieved or it's fit to a receiver whose face is out of square with the chamber axis. Good barrels fit correctly to receivers will shoot sub MOA for dozens and sometimes hundreds of shots.

 

[mrultramag]

Well, you go right ahead and shoot your guns that way... fine by me.

 

[mrultramag]

FYI- thats not the reason we let the barrel cool after 3 shots. Barrels tend to last much longer, especially in the throat area; when you do not continue to shoot once it gets piping hot.... nothing to do with accuracy... although on factory rifles the accuracy usually goes south as the barrel heats up. the smaller the contour of the barrel and the more powder the cartridge uses make the barrel heat up faster... thus letting it cool every 3 shots... maybe a 223 with a bull barrel might be able to shoot 10 times before the barrel is piping hot... YMMV

 

[Bart B]

Barrels tend to last much longer, especially in the throat area; when you do not continue to shoot once it gets piping hot.... nothing to do with accuracy

Having worn out 15 or more .308 Win. barrels in competition, those that were fired once every minute to minute and a half over 30 minutes lasted just as long as those that had half of their shots fired once every 5 or 6 seconds for a minute and half of them fired once a minute for 20 minutes. About 3000 rounds each before accuracy dropped off a noticable amount.

 

[mrultramag]

15 barrels... that's alot of shooting... ill take you at your word regarding barrel heat and accuracy..