Ballistics Question: .357 Sig & .357 Magnum

[Old Man Rufus]

I've been curious about this one. I've heard the bullet velocity is the pretty much the same out to a specified distance (25 or 50 yards, not sure which), but then the Sig falls off pretty quickly compared to the Magnum.

Is this true, and if so what is the difference in effective range for the two rounds? I know the Magnum has a much longer shell casing and should hold a bunch more powder.

Thanks for your input.

[9mmPara]

From what I know(very little! ) .357SIG was developed to have equivalent power of the magnum brother. I don't know how much powder difference there is, but .357SIG case is a necked down .40S&W case, and my guess is that it holds very close amount of powder as the magnum.

Ballistics wise, I have no clue, as I'm not familiar with the data. But I won't be surprised if the data is really close to each other.

Someone who reloads might know better.

[dark_syde99]

The .357 SIG was engineered to provide the same ballistics and even a similar (but more catastrophic) wound channel.

I have not heard of the drop off in performance out at 50 yards, but honestly, I would care too much about it if it were true. It could be REALLY hard to justify shooting someone at that distance.....

[ampleworks]

The biggest difference between 357 sig and magnum is going to be the bullet weight. From what I've seen, 147 grain is about the ceiling for factory ammo.

The magnum's velocity will be 200-300fps higher than that of 357 sig normally.

[ichy_trigger]

The .357sig is a ballistic twin to the .357 mag in the 125 grain bullet weight. If they are leaving the barrel at the same velocity and the bullet designs are the same then max effective range and the ballistics will be identical.
The .357sig 125 grain loading was developed to match the .357 mag 125 grain loading because it was determined that the .357mag had the most effective real life shooting success of any other round for one shot stopping power. I dont have my load manual and ballistic charts with me at the moment but if memory serves me right, the .357 will only be an inch low at 100 yards with a 25 yard zero, but I may be wrong. Remember, a bullet leaves the barrel traveling in an upward direction and passes through the line of sight at a certain distance. It then reaches its peak in that arc and begins to pass back through the line of sight traveling in a downward direction as gravity takes its toll. A cartridge which shoots with a lower arc is what is called a FLAT shooting cartridge.

[mcb]

The one kicker most factory loads do not take full advantage of the 357 magnums case volume or pressure spec. They load then down a touch due to the number of aging old 357 mag revolvers out there. You can beat the 357 Sig fairly handly with handload that run right up to the SAAMI spec especially with heavier bullets. Other guys will actually exceed the SAAMI spec but this is only recomended for the Ruger Blackhawks and Thompson Center Contenders or Encores. I have seen several reloading manual with a special 357 maganum data just for these weapons. Using these gun you can safely load 180 grain bullet in a 357 Magnum that have muzzle energies equal to factory 180 grain 44 Magnum loads and due to the higher sectional density carry that energy further down range.

Rambling
mcb

[Ed Ely]

The best source of info, I believe that Pete is a
member of this forum, on the 357SIG round -

http://www.handguninfo.com/Archive/www.Pete-357.com/

I carry both rounds at different times and at no time
do I feel under-gunned when I carry either. On the other
hand, I have 5 or 6 rounds of .357 Maggie, then with
357SIG I have 13 rounds in a semi. Both rounds can
shoot past the 50 yard line, but shooting at someone at
that distance is not a football game. Of all firearm calibers,
the 357SIG is my favorite. I do refer to it as my '9mm
magnum'. By the way, the 357SIG round is NOT a necked
down 40. It is a specially designed cartridge to contain
the pressures demanded of it, which are way past the 40.

Ed

[Ctkelly]

Double tap ammo has some impressive ammo for the .357 SIG and .357 Mag.

357 Mag Double Tap 125grn gold dot
Velocity: 1600fps / 4" Ruger GP-100
Muzzle Energy: 710 ft. lbs.

357 SIG Double Tap
Bullet : 125gr. Gold Dot JHP
Ballistics : 1450fps / 584 ft. lbs. 4"bbl

[ichy_trigger]

By the way, the 357SIG round is NOT a necked
down 40. It is a specially designed cartridge to contain
the pressures demanded of it, which are way past the 40.

This is good info for anyone thinking they can resize .40 brass into .357sig brass. The sig brass is THICKER in order to contain the higher pressures as Ed pointed out. The .40 s&w spec being 35,000 and the .357 sig spec being 40,000.

I use my .357's for my winter carry. Ive heard some people saying winter coats slow down a 9mm enough to severely handicap its penetration. This will never happen with this little rocket of a round.

[Old Man Rufus]

Thanks for the info, guys. Answers a lot of questions for me.