TargetTalk

Hello everyone,
Recently I had a discussion after I tested the V1 of several types of smallbor ammo. Of most types the V1 was aprox. 5 to 15m/s lower then mentioned by the manufacturers in their tables. I used an Anschutz and Walther rifle. The difference in speed occured only with smallbore, not with air rifle pellets so I beleive the chronometer was not the reason (otherwise the air rifle pellets would have regestered slower also).
Does anybody know what kind of barrels are used by the manufactures for testing the ammo? I know the barrels are a few centimeters longer then standard barrels. But do the barrels have a larger diameter etc. are the lapped/polished inside etc?

Thanks,
Albert B
The Netherlands

The American National Standards Institute (ANSI) and the Sporting Arms and Ammunition Manufacturers Institute (SAAMI) have published a standard method for reporting velocity and pressure in .22 rimfire ammunition. The Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives (Permanent International Commission for Firearms Testing - commonly abbreviated as C.I.P. or CIP) has an analogous function in the member nations.

You are not likely to duplicate the reported results unless you use the standard measuring equipment under the standard conditions.

To actually answer your question, at least in part, the SAAMI standard calls for a 24 inch +/- 0.010 inch (609.6 +/- 0.25mm) long barrel. The chamber dimensions are shown in the standard. The velocity is measured with a 100KHZ (minimum) chronograph using photoelectric screens spaced 20 feet apart with the first screen five (5) feet from the muzzle and the second screen twenty-five (25) feet from the muzzle.