Chronograph of sidewinder vs BW

[Bluelitenin]

I went to the range yesterday and my friend brought his chronograph . I was using CCI maxi mag. The sidewinder read 1046 feet per sec. The Black Widow was only 886 ft/sec. I was surprised because I thought the BW would be higher because of the longer barrel. It might be because the BW is newer and might be tighter. I have probably 4-500 rounds through the sidewinder and only maybe 200 through the BW. Just for reference the PMR 30 was at 1330 ft/sec.

[grayelky]

My guess would be the SW chamber is a little tighter than the BW, thus causing the pressure to be higher. Your BW showed (to me) surprising low velocity.

[Dinadan]

Bluelitenin - Interesting! Your results the opposite of what I would have expected to see. Like you I would have expected the Black Widow to out perform the Sidewinder due to the longer barrel. How many rounds did you measure? You do not mention averaging, so I assume one round each gun?

I note that on NAA's ballistics page, out of four groups of CCI Maxi Mag out of the BW, the lowest velocity was 915 fps. That puts your number a little below NAAs lowest. On the other hand, out of four groups of CCI Maxi Mag out of the 1 5/8" Magnum Mini (no Sidewinder stats there yet) the highest velocity was 941 fps. That puts your number well above NAAs highest for a gun with a barrel that is longer than the Sidewinder's.

I kind of wonder about the chronograph. Did you and your friend test any other guns and ammo?  And were the results close to what you expected?

[Bluelitenin]

Yeah, I would have thought it to be higher.

[Bluelitenin]

Bluelitenin - Interesting! Your results the opposite of what I would have expected to see. Like you I would have expected the Black Widow to out perform the Sidewinder due to the longer barrel. How many rounds did you measure? You do not mention averaging, so I assume one round each gun?

I note that on NAA's ballistics page, out of four groups of CCI Maxi Mag out of the BW, the lowest velocity was 915 fps. That puts your number a little below NAAs lowest. On the other hand, out of four groups of CCI Maxi Mag out of the 1 5/8" Magnum Mini (no Sidewinder stats there yet) the highest velocity was 941 fps. That puts your number well above NAAs highest for a gun with a barrel that is longer than the Sidewinder's.

I kind of wonder about the chronograph. Did you and your friend test any other guns and ammo?  And were the results close to what you expected?

He was measuring his reloads for his 7mm hunting rifle. His velocities were in line with what he expected. He was measuring 2940 ft/sec average for his rifle. This was my first experience with a chrono. I did shoot around four rounds per gun. Some didnt register. But I did get at least two readings per gun. the sidewinder was over 1000 ft/sec for both and the black widow was around 900 ft/sec., the highest being 927 I believe. The main idea was that the BW should be higher.

[boone123]

Bore size, cylinder gap, size of the chambers, could all make a difference.

[MR_22]

Hmm. That's quite surprising. I'm tempted to try that test myself. I'll put it on the list!