Do You Know This Cartridge?

Do you know this cartridge?


Do You Know This Cartridge?

“The .270 Weatherby Magnum was the first belted magnum based on the .300 H&H Magnum to be developed by Roy Weatherby in 1943.[2] The cartridge is short enough to function in standard-length long actions with a brass length of 2.549″ or 64.74mm and an overall length of about 3.295″.[2] It has the characteristic double-radius shoulders and is necked down to accommodate the .277 in bullets. Like most Weatherby cartridges, the .270 Weatherby was standardized by the Small Arms and Ammunitions Manufacturers Institute in 1994, and it has a SAAMI maximum pressure limit of 62,500 psi. The first Weatherby cartridge to be used in Africa was the .270 Weatherby on a jackal on June 8, 1948.[3]


        • ^ “.270 Weatherby data from Accurate Powder” (PDF). Archived from the original (PDF) on 2007-09-28. Retrieved 2007-08-18.
        • Jump up to:a b Bullets, Speer (2009). Speer Bullets Reloading Manual #14. Speer. p. 340. ISBN 978-0-9791860-0-4.
        • Jump up to:a b Nosler, Inc. (2002). Nosler Reloading Guide (5th ed.). Bend, OR, USA: Nosler, Inc. pp. 219–224.


You’ve got to love Wikipedia!

I was testing one of our Long Range Hunter rifles chambered in 270 Weatherby the other day and the results got me thinking two things.  First, “Why isn’t this cartridge more popular?” and second, “What smart, savvy customer ordered this rifle?”.

I mean, look at the data.

Muzzle Velocity: The 24” barrel I was shooting produced 3268 fps with factory Weatherby 130 TTSX ammunition.  A 26” barrel would generate about 3380 fps. 

If you sight in 1” high at 100 yards, you are dead on at 225 yards and only 1” low at 250 yards.  At 300 yards drop is 3.7”. That is pretty flat shooting!

Using the same zero, drop at 400 yards is barely over a foot at 13” and the 130TTSX does not even have that high a ballistic coefficient.

What about drop at 1000 yards?  I really don’t care.

Data for the 140 Accubond load is even better.  However, I am sticking with the TTSX here because you can hunt with it in areas that don’t allow lead core bullets.

Foot Pounds of Energy:  At 300 yards the 270 Wby with 130 TTSX has 2100 foot-pounds of energy. At 500 yards it is still pounding away with over 1500 foot-pounds of energy.  These numbers exceed 270 WSM, 6.5 PRC, and 7mm Rem. Mag. even with slightly heavier 140ish grain bullets.

What about Energy at 1000 yards?  I could not care less.

Accuracy: We guarantee the same 3-shot, ½” groups at 100 yards in the 270 Wby as we do for other calibers we offer.

I think there are some misconceptions about the accuracy of Weatherby cartridges that are explained below.

  1. Weatherby rounds use too much free-bore and therefore do not shoot as accurately as other cartridges.
    1. While I am sure there are a few bullets that need to be close to the lands to shoot well, the bullets you want to shoot at these velocities, on medium to large game, do not seem to care.  Again, our accuracy guarantee for the 270 Wby is still ½ MOA.
    2. One of the unique aspects of the Weatherby case design is the double radius shoulder which increases chamber pressure, requiring less gunpowder to achieve velocity.  The free-bore allows this pressure to build safely, without sticky cases or blown primers.   Free-bore, in this case, is a good thing.
    3. Weatherby rifles used to be famous for gorgeous walnut stocks and long, skinny barrels in a beautiful, high-luster blued finish.  The actions were not bedded.  The barrels were not free-floated.  Most people considered a 1.5” grouping rifle to be “good enough to hunt with”.  This is where the bad rap on Weatherby accuracy comes from.  People have assigned it to free-bore when it was mainly gun design that valued appearance over accuracy because that is what the customer valued most at that time.
  2. Non-belted magnums are more accurate than belted magnums
    1. BALDERDASH! We have built hundreds of rifles in belted and non-belted cases and there is literally ZERO accuracy difference between them.  Myth rejected and dispelled by the real world.
    2. I will tell you one thing I actually love about belted magnums as compared to non-belted magnums; they feed perfectly!  If you have owned a non-belted magnum like a WSM, Ultra Mag., or Nosler magnum, odds are pretty high you have had a feeding problem at some time or other.  Non-belted cases are fat, don’t have much body taper, and the shoulder diameter is much larger than that of a belted case.  All of that makes feeding from a magazine tricky. If you run the bolt too slow, the round might pop out of the box too early.  Run the bolt too fast and the butt of the cartridge sinks too deep into the mag box and jams.  We spend a lot of extra time tweaking mag spring tension, mag box shape, mag follower shape, and so on to get non-belted magnums to feed properly.  The belted magnums have more body taper and a smaller shoulder diameter which combine to allow the cartridge to slide smoothly from the magazine box and into the chamber with ease and no mishaps.

Another attractive feature of the 270 Wby is recoil.  Yes, it is a magnum, but for a magnum caliber recoil is not bad at all.  It is certainly less than the 7mm Rem. Mag. and about the same as a 270 WSM.  So, shooting the rifle without a muzzle brake is very doable without crushing your shoulder or causing a flinch.


Do You Know This Cartridge?Compare the 270 Wby, created in the 1940’s, to the NEW 27 Nosler.  Even Nosler’s optimistic numbers show only 3” less drop at 500 yards than the 270 Wby.  We find that most Nosler ammo we test chronographs well below the box velocity number and is very inconsistent across different lots of ammunition.  The 270 Wby uses less powder (longer barrel life) and has an established track record of ammunition availability and consistency.  Feeding will be a constant issue with the 27 Nosler since the shoulder diameter is almost .040” larger than the 270 Wby case.  The larger shoulder diameter hits the feed ramp too soon, causing the cartridge to pop up or wedge into the magazine box.  This almost never happens with a belted magnum case that has a smaller shoulder diameter.

One other comment about how these rounds are promoted.  A 150-grain bullet does not an Elk Cartridge make.  Velocity generated energy is not the same as mass generated energy.  Mass generated energy is what drives a bullet through heavy bone and tissue.  Velocity generated energy is the first thing to dissipate when a bullet hits heavy resistance.  If you want to crush though an Elk shoulder and get full penetration, use a cartridge with a heavier bullet, even if it is not as fast.

Is the 270 Weatherby the most amazing cartridge ever?  No.  It is just a very solid round that has been around for over 70 years.  It feeds great.  It is extremely accurate.  It has moderate recoil.  And the factory Weatherby ammo, which has been around a long time, is excellent and will be around for years to come. 

As a Whitetail, Sheep, and Mule Deer cartridge, it is an excellent choice and should not be overlooked simply because it is not all new and shiny.


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