Thread: chrony on factory loads

Originally Posted by NewbieZAR

Yup same here, i have 100x sako 55gr 22250 rounds, and in my ackley chamber they chrony 3360fps with the magneto speed vs packet velocity of around 3600fps. 23" barrel, but it is also being fireformed.

On the other end, i have a 308 with a 20" barrel and an obermeyer chamber (tighter than saami) and i actually get pressure signs with sako 150gr factory ammo, and it measures ar 2850 which is faster than i think the 2800 on the packet

Greetings NewbieZAR,
Your Ackley Improved chamber will reduce the velocity of factory loads significantly whether a fire forming load or not. 240 fps does not sound out of order. Also for all the reduction in velocity in non magnum cases generally works out to 20 to 30 fps per inch below 24 inches. Loads for many cartridges have been dialled back by the manufacturers due to the more accurate pressure reading equipment now in use. The .243 Winchester and 7mm Remington magnum have lost most. Published load data has been dialled back as well. The published data for factory ammo has not always followed.
Regards Grandpamac.