what caliber shoots more flat?

[dbllunger]

Rob...you are getting into the technical but data needed questions.  Again some data is guesses and some is real, so you have to find what works for you.  I'm trying here, but your questions have so many variables to consider.

What ranges are you talking?
The higher BC (Ballistic Coeficient) bullet going the highest FPS will be flattest period.
In order to accurately compare rounds you need to compare equal bullet weights.

Of the two rounds shooting equal weight bullets the 7mm Mag will be flatest due to higher FPS.  Going the same FPS with same weight bullets the 270 will be flatter due to higher BC.

High BC is not as important to killing animals as high SD (Sectional Density).  

Starting to understand there are a lot of variables.

Also some rifles won't hit top speed without a longer barrel.

You will never get a true 3600fps out of a 7mm Remington Mag with a 120gr bullet.  Maybe in a 7mm STW but not the Remington.

You cant get a true 3600fps with a 165 out of a 300RUM and 3800 with a 150.  Barrel life will be the same regardless of bullet shot if all are shot at MAX + velocity.  Most people would never shoot the accuracy out of a hunting rifle barrel.  

Recoil is real simple on the surface.  NEWTONS LAW !!!!!!   Stock Design, Material, Recoil Pad, Rifle Weight, and barrel length all determine recoil.  Just count on the faster the bullet is going the more recoil in general is going to be created.  

If you debating a 7MM Rem Mag over a 270 I would go with a 7mm, but if you are worried about recoil then the 270.  Better to hit with a 22 then miss with a 50!

Keep the questions coming and hopefully we can help you out.  
  

[huntnphool]

Good info DBL

[jmkuhlman]

If you are looking to choose between the .270 and 7mm, I'd start with the 7mm.  It has better versatility and a bit more knock down power at longer ranges.  A 7mm gives you the ability to shoot 180 grain bullet without giving up velocity.  By the same token, you can go as light as 120 grains.  If your a reloader, you can make the perfect round for the game your hunting.  I happen to reload both.  But I only reload 140 grain in the 270, while I reload three different grains in the 7mm (120, 140, & 169).    

[bobcat]

When you mention 270 and 7mm you aren't specifying which cartridge you're talking about. In 270 there are only a few...270 Winchester, 270 Winchester Short Mag, 270 Weatherby Mag.  Then in the 7mm you've got 7x57 Mauser, 280 Remington, 7mm Remington Mag, 7mm Winchester Short Mag, 7mm Weatherby Mag, 7mm Remington Ultra Mag, and this list goes on.

The size of the cartridge and its powder capacity is what determines the velocity potential and therefore how flat it will shoot. The diameter of the bullet really isn't that critical. You can have flat shooting cartridges in anything from 22 caliber up to about 338 caliber. It just all depends on how much powder you're burning and of course along with that comes more recoil. Generally the more recoil, the flatter shooting a cartridge will be.

If you want to compare apples to apples then when you compare 270 to 7mm, you need to use similar cartridges, like the 270 Winchester and the 280 Remington. They are both based off the 30/06 case and therefore have similar powder capacity, and basically there is no difference in the trajectories betwen the two. Comparing a 7mm Magnum to a 270 Winchester is not a fair comparison. Sure the 7mm will shoot flatter but it also burns more powder and recoils more.

[Red Dawg]

 

[haugenna]

When you mention 270 and 7mm you aren't specifying which cartridge you're talking about. In 270 there are only a few...270 Winchester, 270 Winchester Short Mag, 270 Weatherby Mag.  Then in the 7mm you've got 7x57 Mauser, 280 Remington, 7mm Remington Mag, 7mm Winchester Short Mag, 7mm Weatherby Mag, 7mm Remington Ultra Mag, and this list goes on.

You beat me to it. This is for factory guns with 26" barrels max.

The 7mm RUM is the flattest shooting out to 1000yds using a 168 grain Berger Bullet for hunting, and a 168 grain A max for targets.

It passes the 30-378 weatherby at 600 yards.  

I think the big 338's  (338 Lapua and Edge, and 338-378 pass them both up at 1000yds with the 300 grain sierra matchkings.

[jmkuhlman]

Recoil depends on your headspace. My 7mm has no kick while my 270 does. Recoil is based on the rifles OAL and I'm sure this is different with each of the various manufacturers.  I measure my chamber and then set the bullet depth to .005 off the OAL. This also helps with accuracy and more accurate rounds are generally a fraction longer than the OAL specification. My 270 chamber is just too long to get the ideal seating with 140 grain bullet however, so it has more kick.  

Sorry about the earlier post, 270 Winchester and 7mm Remington Mag

[demontang]

The 270/7mm are both great rounds it all depends on what range he is thinking and how much recoil you can take.

The .338 cal's start to shine past 1000yds.

[dbllunger]

Rob....Now don't forget wind drift!!  Have you thought about that variable and KE (Kinetic Energy) and bullet design?   

[270Shooter]

.270 win shooting 140gr nosler accubonds at 2950Fps. Federal Premium
50 Y 100 Y 200 Y 300 Y 400 Y 500 Y
0.6   1.5    Zero  -6.7   -19.5   -39.3

7mm Rem Mag shooting 140 gr nosler accubonds at 3110 fps. Federal premium.
 50 Y 100 Y 200 Y 300 Y 400 Y 500 Y
 0.4   1.3    Zero   -6.0  -17.4  -35.2

When both are Zeroed at 200 yards there isn't much of a difference in trajectory. The 7mm beats the .270 by 2 inches at 400 yards. Also the 7mm is only generating 171 more pounds of KE at that same distance. But the 7mm kicks more and burns more powder. To ME the .270 makes more sense.

[huntnphool]

When both are Zeroed at 200 yards there isn't much of a difference in trajectory. The 7mm beats the .270 by 2 inches at 400 yards. Also the 7mm is only generating 171 more pounds of KE at that same distance. But the 7mm kicks more and burns more powder. To ME the .270 makes more sense.

I have to agree with JMK, my 7MM doesn't kick as much as my .270 shotting the same 140gr., maybe its the difference in the manufacturer

[Huntbear]

I read an article in one of the shooting rags a few years ago, trying to find it again.. that said, the .338 WM with 200 - 210 gr. bullets shoots flatter than a 7mm mag with 175 gr. bullets. (they supplied the data to back it up as well)  Plus, you have the added energy of the bigger bullet.  My brother and I have both owned and shot 7 mags.  They are now in someone else's gun safe.  We shoot .338 WM for all of our long range work.  Deer or Elk.  You do your job, out there at the long ranges, the .338 will do its job as well.

Just my  

[haugenna]

chuckhawks.com used to be a good site for this info on recoil and trajectories, but then he went and go greedy and requires a paid membership to view his information.

[catwithboost]

Not a big fan of large grain bullets in a 7mm mag. I shoot 140gr Tipped TSX so I stick with 7mm for flat shooting. Yes you can shoot 338wm or 50cal but I like to shoot a deer and have meat to take home.  Also a lot has to do with what you feel a flat shooter is out to as far as yards and what you are hunting with it.

[alanger]

7mm mag