Buffalo Bore. I don't understand

[Doug.38PR]

1. How is it that with the lighter weight bullets, the bullet's velocity is higher in shorter barrels than longerbarrels of older S&W revolvers? I saw their explaination, but it doesn't make any sense. ALSO, the heavier bullets (180gr) rise in velocity with the longer barrels, including the older M27, aren't they affected the same way? At least my 6 inch M28 can handle the hotter loads better AND get higher velocity. But 6 inches is 6 inches and 2 inches is 2 inches. How do you account for the difference in lighter loads?

About Buffalo Bore 357 Mag. ammo

Our 357 mag. ammo adds more power than ever before to the 357 mag. This ammo is safe to shoot in ANY all steel 357 revolver—this includes J frames. This ammo is no harder on your gun than any other normal 357 ammo. Please don’t phone us and ask if this ammo is safe in your gun. It is, providing your gun is in safe condition for use with any normal 357 ammo.

We don’t recommend this ammo to be fired in super light alloy revolvers as bullets may jump crimp under recoil, but the ammo itself wont hurt these super light weight revolvers. These revolvers are simply so light that the recoil is severe enough to cause crimp jump.

The below velocities are offered so that you can see what guns/barrel lengths give what velocities with this new 357 mag. ammo. You’ll notice that new S&W revolvers with short barrels are often shooting faster than older S&W revolvers with longer barrels. The new S&W revolvers are very good and are made with equipment that makes them more consistent and faster than the S&W revolvers of yesteryear.

Make special note of the Marlin 1894, 18.5 inch barrel velocities. Item 19C/20, supercedes 30-30 energies!!!

1. 3 inch S&W J frame

a. Item 19A/20-180gr. Hard cast LFN = 1302 fps
b. Item 19B/20-170gr. JHC (jacketed hollow cavity) = 1299 fps
c. Item 19C/20-158gr. Speer Uni Core = 1398 fps
d. Item 19D/20-125gr. Speer Uni Core = 1476 fps

2. 4 inch S&W L frame Mt. Gun

a. Item 19A/20-180gr. Hard cast LFN = 1375 fps
b. Item 19B/20-170gr JHC = 1411 fps
c. Item 19C/20-158gr. Speer Uni Core = 1485 fps
d. Item 19D/20-125gr. Speer Uni Core = 1603 fps

3. 5 inch S&W model 27

a. Item 19A/20-180gr. Hard Cast =1398 fps
b. Item 19B/20-170gr. JHC = 1380 fps
c. Item 19C/20-158gr. Speer Uni Core = 1457 fps
d. Item 19D/20-125gr. Speer Uni Core = 1543 fps

4. 6 inch Ruger GP 100

a. Item 19D/20-125gr. Speer Uni Core = 1707 fps

5. 18.5 inch Marlin 1894

a. Item 19A/20-180gr. Hard Cast = 1851 fps
b. Item 19B/20-170gr. JHC = 1860 fps
c. Item 19C/20-158gr. Speer Uni Core = 2153 fps---- Can you believe this?!!!
d. Item 19D/20-125gr. Speer Uni Core = 2298 fps---- Or this?!!!

 

[joneb]

hmmm magic bullets ? ahh I've been waiting for these but it sounds to good to be true

 

[DWARREN123]

Most likely the powder used.

 

[Jim March]

Nope. It's not the ammo or it's being tuned to short barrel length, it's all about more modern barrels with better and smoother designs.

Look at the one test of the Ruger GP100 6" barrel. It's WAY hot 250fps faster than the same load in the 5" S&W older-model barrel. IF the barrels were equal quality you'd only expect a 50fps or so difference. Instead we see 250fps difference.

Unfortunately they only tested that one load with the 6" Ruger but if they'd done the other three I'll bet good money the pattern would hold. Look at the Marlin rifle loads: these BuffBore rounds are clearly still hot as hell and doing very surprising power levels (exceeding many 30-30 rounds). If the slugs were tuned for short barrels they would seriously run out of steam in the rifle. They clearly haven't and are performing damned well in the longer rifle tube.

The later-model S&W keeps pace with the Rugers, so don't see this as "Ruger partisanship" on my part.

 

[Steve C]

All the loads had appropriately higher velocities in the longer barreled pistols except for the jump from the 4" Mtn Gun to the 5" M27. Since there's often over 100 fps difference in velocities with the same ammo in different firearms of the same barrel length the results are within the expected parameters. A difference of 1" in barrel length wouldn't be expected to necessarlly result in higher velocites for the longer barrel. The 4" pistol may have been one that normally shoots fast while the 5" gun puts them out at less than optimum due to varous reasons. You really can't generalize from such a small data sample.

 

[Doug.38PR]

EDIT: I get it.

How do you measure how fast the round is going? Some kind of instrument? Where can you get one? How much are they?

 

[ugaarguy]

How do you measure how fast the round is going? Some kind of instrument? Where can you get one? How much are they?

http://www.cabelas.com/cabelas/en/c...mode+matchall&Nty=1&Ntt=chronograph&noImage=0

 

[MachIVshooter]

How do you measure how fast the round is going? Some kind of instrument? Where can you get one? How much are they?

A Chronograph (Chronometer). Chronographs work in the same way as police used to determine vehicle speed before the days of radar; by measuring the time it takes for an object to get from one fixed point to another. A chronograph simply measures the time elapsed between the bullet passing over the front and rear sensors.

The mainstream brands are Oheler and Chrony. The Ohelers are excellent units, but spendy. You can get Chrony brand chronographs for under $100, with their top-end model just over $200. I have the best Chrony and it works well as long as the diffusers are in good shape. It will measure the speed of anything traveling faster than 70 FPS and slower than 7,000 FPS, which covers all firearms and most bows.

 

[JoeHatley]

How do you account for the difference in lighter loads?

Powder

Joe

 

[bakert]

In the Speer Manual 13 on page 443 there's a chapter titled "Why Ballistics Get Gray". It shows Speer's test with the .357 in barrel lengths from 2.5" revolver to to 24 rifle . Often two different guns even from the same manufacturer with same barrel lengths can vary tremendously. Most times the shorter barrel will show less velocity but not always. Interesting reading and eye opening info.