.357 Magum Velocity Gain

[Amac91]

.357 Magnum Velocity Gain

I'm considering picking up a .357 long gun. My question is, is there a substantial velocity gain in a 22" barrel over a 16" barrel? Any values (speed and energy) for comparison with say a 180gr load? Looking at a 16" lever action or possibly a Handi-Rifle.

 

[BehindBlueI's]

Even with the heavy 180gr hunting loads, nothing significant. Maybe 100-120fps or so. If you handload, you may be able to do better, but I've never played with loading .357.

Lighter bullets, those made with revolvers in mind, are usually "tuned" for a 6" barrel and will actually have less velocity in the 22". They tend to peak out around 16" or so.

 

[Amac91]

Good to know. Any opinions/experience with Handi-Rifles out there?

 

[doddsracing]

I agree the 16" will have more than the 22". I have a revolver in 7 1/2 " and with light hot loads it runs faster than my rifle ,with heavy bullets and slow powder the rifle is faster about 200fps.

 

[Amac91]

Recommendations on 16" .357's? Open to suggestions.

 

[doddsracing]

I had a winchester then bought a stainless rossi, it shot better than the winchester so I sold the winchester,the rossi does not feel as slick as the winchester did, but I like stainless guns.

 

[Osobuco]

Go here for barrel length vs muzzle velocity

Topic of the Month

also from Chuckhawk


Velocity loss (or gain)

It is worth noting that the velocity figures published in ammunition brochures and reloading manuals are sometimes taken in barrels different in length from those supplied on many rifles. I have seen various estimates of how much velocity is lost (or gained) when a barrel is not the same length as the test barrel in which a cartridge was chronographed. Here are some of them.

The 2001 Edition of the Shooter's Bible states, in the introduction to the Centerfire Rifle Ballistics section, "Barrel length affects velocity, and at various rates depending on the load. As a rule, figure 50 fps per inch of barrel, plus or minus, if your barrel is longer or shorter than 22 inches." However, they do not say what category of load to which this 50 fps average pertains.

Jack O'Connor wrote in The Rifle Book that, "The barrel shorter than standard has a velocity loss which averages about 25 foot-seconds for every inch cut off the barrel. Likewise, there is a velocity gain with a longer barrel." He went on to illustrate this using a .30-06 rifle shooting 180 grain bullets as an example, so his estimate was obviously for rifles in that general performance class.

Other authorities have tried to take into account the different velocity ranges within which modern cartridges operate. The Remington Catalog 2003 includes a "Centerfire Rifle Velocity Vs. Barrel Length" table that shows the following velocity changes for barrels shorter or longer than the test barrel length:

• MV 2000-2500 fps, the approximate change in MV per 1" change in barrel length is 10 fps.
  MV 2500-3000 fps, the approximate change in MV per 1" change in barrel length is 20 fps.
  MV 3000-3500 fps, the approximate change in MV per 1" change in barrel length is 30 fps.
  MV 3500-4000 fps, the approximate change in MV per 1" change in barrel length is 40 fps.
  

The 45th Edition of the Lyman Reloading Handbook also has a table showing Center Fire Rifle Velocity Vs. Barrel Length. Their figures apply to barrels between 20 and 26 inches in length and agree with the Remington figures. The Lyman table shows the following approximate velocity changes:

• For rifles with muzzle velocities in the 1000-2000 fps range, the change in velocity for each 1" change in barrel length is 5 fps.
  For rifles with muzzle velocities in the 2001-2500 fps range, the change in velocity for each 1" change in barrel length is 10 fps.
  For rifles with muzzle velocities in the 2501-3000 fps range, the change in velocity for each 1" change in barrel length is 20 fps.
  For rifles with muzzle velocities in the 3001-3500 fps range, the change in velocity for each 1" change in barrel length is 30 fps.
  For rifles with muzzle velocities in the 3501-4000 fps range, the change in velocity for each 1" change in barrel length is 40 fps.

The 43rd edition of the Lyman reloading Handbook gave some concrete examples of velocity loss for specific calibers and loads. The Lyman technicians chronographed some high velocity cartridges in rifles with barrels ranging in length from 26 inches down to 22 inches with the following results:

• The average loss for the .243 Win./100 grain bullet was 29 fps per inch.
  The average loss for the .264 Win. Mag./140 grain bullet was 32 fps per inch.
  The average loss for the .300 H&H Mag./220 grain bullet was 25 fps per inch.

For standard high intensity cartridges in the same test, the Lyman technicians chronographed the cartridges in barrel lengths ranging in length from 24 inches down to 20 inches with the following results:

• The average loss for the .270 Win./130 grain bullet was 37 fps per inch.
  The average loss for the .270 Win./150 grain bullet was 32 fps per inch.
  The average loss for the .300 Sav./180 grain bullet was 17 fps per inch.
  The average loss for the .30-06/180 grain bullet was 15 fps per inch.
  The average loss for the .35 Rem./200 grain bullet was 11 fps per inch.

After a bunch of disclaimers, the Lyman people concluded, "The rule of thumb is that high speed, high pressure cartridges shed more speed in short barrels than do the low speed, large bore types." It's funny, but that is what I had suspected all along!

 

[kludge]

BBTI - Ballistics by the Inch :: Home

 

[Hookeye]

Interesting post showing bbl length affecting velocity over different types of cartridges.


But the min bbl lengths for the two groups shown was 22 or 20".

No test results for bbls less than 20".

Also.............I strongly suspect the same powder/bullet was run for each cartridge.

Other propellant and or bullet weight combinations may show added effects.

Ex: I run AA4350 in a .243 with 7O grainers, and the powder is a bit slow- I get a lot of boom and flash with a 22" bbl. Not the most efficient, but it shoots very well so I run it.

 

[ROLEXrifleman]

Slow burning powder requires longer barrel length to get max velocity
fast burning powders need shorter barrels. Anything longer than optimum length and then friction starts to slow the bullet down in the barrel

 

[Hookeye]

Yeah but where does one go to see a bbl length test done with that also taken into account (across different types of cartridges)?

Folks do all these "tests" but don't take things as far as they should scientifically.

Kinda p*sses me off, how some (not all) make definitive claims based on a minor grouping at data (and some of it corrupted).

Gets d*mn messy when you start tossing in a few variables, doing such test methods correctly.

 

[in625shooter]

I have never shot or chrono's any 180 gr but with 125 and 158 grain I gained right at 400 FPS with both wirghts in my 1894 Marlin over my 4" 686. While you could come up with a ball park estimite, It might be woth the effort to find someone with a chrono and just see what your rifle does with them Each rifle has it's own way of shooting.