.300 win mag or .7mm build?..

[motg9_6]

have a 7mm built by allbull in montana. shooting 850 with no problems just waiting for deer season and a good high mtn hunt
168 grn berger bullet 70grns rutumbo

[NW-GSP]

I have a Remington 700 .300 win mag that I am wanting to do the same distance with as you are.
I just have to save up to get it done.

Both calibers are really good I think it will be more personal preference then anything.

[Three_Oh_Eight]

Check magazine restraints before choosing.  300 Winnie in most standard actions will not fit the mag and still kiss the lands.  7mm Rem does not have this issue.  Or, just run a full-length action and seat bullets to your heart's content.

For all of you claiming the merits of a 7mm over a 300, I wonder what "performance" gains you are getting from a 7mm over a 300?  162 Amax .625 BC at 2900 fps drops about 20 or 25 inches more at 1000 yard than 208gr Amax .648 BC at 2900 fps.  Sure, more recoil.  But, bigger bullet with less drop seems like mo-betta.

[JPhelps]

I'm glad my 7mm mag pushes the 180 bergers at 3050

[actionshooter]

Check magazine restraints before choosing.  300 Winnie in most standard actions will not fit the mag and still kiss the lands.

This is a very good point,
 I found out the expensive way.

[rbros]

Check magazine restraints before choosing.  300 Winnie in most standard actions will not fit the mag and still kiss the lands.  7mm Rem does not have this issue.  Or, just run a full-length action and seat bullets to your heart's content.

For all of you claiming the merits of a 7mm over a 300, I wonder what "performance" gains you are getting from a 7mm over a 300?  162 Amax .625 BC at 2900 fps drops about 20 or 25 inches more at 1000 yard than 208gr Amax .648 BC at 2900 fps.  Sure, more recoil.  But, bigger bullet with less drop seems like mo-betta.

Mainly due to the fact that a properly built 7 Rem Mag will run 180 Bergers .659BC at 3050 and the 162's at 3100+.  These numbers are in 26-27" barrels.  A 300WM in the same length barrel simply cannot keep up, even with a custom chamber.  I have built a bunch of both and the 208's pretty much top out at around 2950 in this barrel length.  Once guys see the performance numbers for real, they typically go with the 7 Rem Mag.  Have built around 200 of them over the past few years and the results have been very consistent.

Mag length isn't a huge concern.  Have your builder set things up properly and use a Wyatt's mag box if needed.

Basically it boils down to this....if you reload, you will get more benefit from the 7mm.  If you buy factory ammo, the 300WM has more choices.

[motg9_6]

 

[jaymark6655]

Fusion 150 grain 7 vs. 300
7 has a high BC .509 to 300's .41
up until 300 yards 300 wins in every cat, but at 500 the 7mm is 70 fps faster, has 99 ftlbs more energy
somehow the 300 will drop and inch less though

because  the 7mm is smaller diameter it seems the ballistic coef for the same weight will always be higher
to compare two rounds of same BC the 300 would need to be close to 180 grains
in that case the 7mm would be about 100 fps faster, the 300 would have about 125 ftlbs more energy, but would drop 3 inches more than the 7mm at 500 yards

The 300 seems to be able to have a higher muzzle velocity for any given weight, but the lower BC really kills the round past 300 yards (too bad, because I like the 300 and already owning a .308 would allow me to use the same 180 grain bullet for each).  On the plus side it looks like the 300 would sling a 220 grain round at the same muzzle velocity as the 175 grain 7mm, depending on BC maybe the 300 could out preform the 7mm there, I would have to check when I get home. 

[Three_Oh_Eight]

Check magazine restraints before choosing.  300 Winnie in most standard actions will not fit the mag and still kiss the lands.

This is a very good point,
 I found out the expensive way.

I have a pre-64 M70 in 300 Win Mag.  I use the 180gr Hornady Interlock BTSP for deer hunting and I have to seat it all the way until the neck is on the cannelure if I want it to fit in the box.  Super-jump into the barrel but it still seems to shoot okay.  Unfortunately, ever since I realized that a rifle I've hunted with for a long time is now worth more than my car, I quit using it as much.

[h2ofowlr]

I went and talked to the guys again at Benchmark today. The individual I spoke with liked the .7mm short mag.  He said he prefers the .7mm as a personal preference.  Easy to manage and a good shooter.  He said when he builds a .300 he typically typically adds about 1 lb to make it more manageable.  Some good info.  He said he likes both calibers, but for hunting up to 800 yards the .7mm would be a good choice.

[762Armo]

With all the info in this thread, I'm glad I went with my 7mm for my hunting rifle.
Now, I need to get into reloading.

[Simcoe hunter]

Thee Mr. Nosler picked the 7 over the 300 due to ballistics and recoil.

[rgalanti21]

I normally like the .300 magnum calibers but if I were doing a custom, it would more than likely be in 7mm mag given the choice between the two. 

[Three_Oh_Eight]

This thread kind of amazes me.  Ask the same question 5 years ago, and anyone "in the know" would always choose a 300 magnum over a 7.  I can see and advantage in recoil, but nothing else.  There is the frontal-area thing too.  A 30 just seems to make a bigger whack when it hits stuff.  Within 400 yards, I actually would choose a 30-06 over a magnum 7 for just about any hunting. 

[johnnyaustin44]

My buddy had benchmark turn his 7 mag into a shortmag so its the same action and magazine with a smaller case to seat the bullet out as far as he wants. Sweet gun. Still waiting on the nightforce purchase though.