by Ed Skinner

Conventional Pistol, a.k.a. "Bullseye", is a high precision pistol competition sanctioned by the National Rifle Association.
 
This publication is © Copyright 2004-2008 by Ed Skinner.
All rights are reserved.

Friday, March 4, 2005

22LR Ammunition Spreadsheet

Email posted to Bullseye-L

The spreadsheet of 22LR ammunition velocities is as ready as it's going to be (for a while). Several had requested copies and those have been mailed. (If you haven't received yours, it's because your Email service bounced my message. Sorry, I can't do anything about that -- but read on, all is not lost.)

The spreadsheet is available to everyone at http://www.flat5.net/ -- that's my family webpage and, near the top, is a section on [shooting] "Bullseye" and a link therein. Follow that link and you'll see a link where you can download your own copy of the spreadsheet. It is "zipped" to save download time.

A word of caution -- spreadsheets are one of the things that *can* carry computer viruses into your computer. Opening the spreadsheet is what springs the virus if there's one there. I'm quite certain this particular spreadsheet is "clean" at this point and if you always come back to this same website for updated copies, you can be assured that I've done everything possible to make sure the file is still clean. But if someone else sends you a copy, be careful. (Hopefully you all have virus-protection software installed, turned on and fully up to date, yes?)

So what have I learned from the spreadsheet?

First, please note that almost all of the listed velocities are measured by manufacturers -- in rifles. And also please note that none of them state whether or not they were using any sort of mutually-used standard. Those two facts mean that 1) you probably won't see these velocities out of your handgun, and 2) comparing one manufacturer's ammo to that of another using this velocity data is, at best, debatable.

But experience does speak rather clearly sometimes.

For example, I've kept pretty good records on how different brands of ammunition have worked in my Smith and Wesson model 41. Having all the possibly-questionable velocities available, I can see a direct correlation between stove-piping and the manufacturer's rifle-measured muzzle velocity even though I'm shooting a handgun. That is, once the rifle-measured muzzle velocity is above a certain number (about 1100 ft/sec), I'll start to see stove-pipes in my S&W 41 and, as the velocity goes higher, the frequency of stove-pipes also goes up.

On the other end of the scale at the slow end, the problems I see in my 41 are typically not cycling the gun hard enough to eject the old round, nor cock the hammer. I end up pulling the trigger harder and harder until I realize it isn't going to go bang! I haven't fired enough subsonic to know where the dividing line is but it certainly looks like "rifle-measured muzzle velocity" will be a good way of deciding what to buy and what to avoid.

More generally, if you "mine" this data and pull out everything that says subsonic, you'll find the average is about 1028 ft/sec. (The speed of sound is generally accepted as 1120 ft/sec at sea level, etc...)

The average "standard velocity" is 1092 ft/sec, still sub-sonic and, frankly, not that much faster than subsonic. That's only a 6% difference. In addition, you'll find that some brands of "standard" are slower than some brands of "subsonic". CCI Standard Velocity, for example, is slower (at 1070 ft/sec) than Eley's Subsonic (at 1085 ft/sec).

There's a very wide range of velocities when it comes to "High Velocity," anything from 1235 to to 1329 ft/sec, and all definately above the speed of sound.

Some of the manufacturers publish handgun-measured velocities as well. I've noted those values in addition to the rifle-measured velocities from the same manufacturer. The average difference (between rifle and handgun muzzle velocity) from these manufacturers is about 15%. That is, if someone tells you a rifle velocity, you may be able to subtract about 15% and come up with a pretty reasonable estimate of what you might see coming out the end of your handgun.

Well, maybe. It still depends on barrel length (shorter = slower), ambient temperature (lower = slower) and probably a dozen other factors as well.

That's it for now.

Gotta get some range time in!

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