Ballistic table BS !!!

It is not unusual for some guns to shoot slower, or faster than expected. I've noted this in the past. The 6" Python they tested for whatever reason is just slower than it should be. All of the others are shooting pretty close to what is expected. I've seen two different 30-06 rifles with equal barrel lengths shoot 130 fps different with ammo from the same box. I've seen 20" 308's beat 22" guns and equal another 24" gun with the same ammo.

FWIW, this isn't the 1st time I've seen data showing Colts shooting slower than other brands. Without mentioning any name brands I've seen other trends where some manufacturers tend to be faster or slower than expected on a regular basis.

This is why any velocity comparisons you see from different guns should be taken with a grain of salt. The data collected from the same barrel as it is cut shorter is far more reliable
 
The data collected from the same barrel as it is cut shorter is far more reliable
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while it is reliable, it's not really any more useful, as the barrel it came from is now in little chunks.

People who know, know, the rest usually don't think about it, until something points it out. There are fast guns, and slow guns. Its all about the individual gun and the ammo being fired, and how they "fit" together. A different gun, even the next ser# off the production line can be an entirely different thing.

Most are pretty close to each other, but both ends of the performance curve are out there. I have seen 100fps difference between three 6" barrel guns firing the same ammo. That much difference isn't common, but it can happen.

A 2" barrel shooting faster than an 8inch is unlikely but has happened as well.

Any claimed velocity may be 100% accurate, for the gun it was fired in. It may, or may not be what you get from your gun and ammo, even if your equipment is as closely matched to the test gun as possible.

My experience is that when talking velocities over a range of guns in a given caliber, any claimed speed different of 100fps or less is well within the normal variation found between different gun and ammo combination.
 
If you compare the data from the http://www.ballisticsbytheinch.com/38special.html website they apparently use the same 6" Python for testing both 38 and 357 mag ammo. It is consistently slower than shorter barreled guns with almost every ammo tested. The issue here is not the testing, just an anomaly with one individual gun.

It's not BS, sometimes stuff like this just happens.
 
lavan said:
I used to use BBTI for reference.
Now I think I may have been pretty dumb to do so.
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Why would you call actual test data "BS"?

The real world doesn't always work as predicted. I personally much prefer actual test data to calculated numbers, even if it does clash with my pre-conceived notions of what "should" happen.
 
Sometimes you measure the wrong thing.

Bill Jordan related a story of observing someone doing some testing with his handloads for his hunting rifle. He did some shooting and concluded that one certain load was more accurate than the others and so it should be his load of choice. But Jordan said "Hold on a minute," (or words to that effect) and chronographed some of the loads. The man's choice load was not by any means the more powerful load, which Jordan thought to be a more important consideration.

It's still up to the user to decide what characteristics are important.
 
Their Python with a 6" barrel is an anomaly with all the rounds they tested, both .38 Spcl and .357 Mag, not just the one pointed out in the OP.
 
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