chrono gone wrong

I noticed that every time i go it seems that the chrono is off at the ACZ field either some one says the chrono is low compared to what there gun supposedly shoots at .
like a 400 + gun chrono's in the mid 350 -375 are the guns not really hitting 400 + or is the chrono OFF



THIS IS NOT TO OFFEND ANYONE AT ALL , MERLY A COLLECTIVE THOUGHT ON THE TOPIC

Heavier BB = more force required to move = less feet per second. Mine chronoed at 350fps, shot exactly like it was 350 fps. Zander's SL9 chrono'd in real low, but all I can say about that is he must have lost compression somewhere.

The chrono is fine bc i have tested my own weapons on it and i know what they shoot and they read fine.

There are two chronos at the shop, both Madbull chronos and one reads higher and one is lower. Now for which one is correct we do not know. The chrono that comes out to the field is the one that reads slightly lower just because thats the newer one that uses batteries instead of the one at the shop which is rigged to plug into the wall.

yeah its fine for the most part, but one time it tried telling me that a gas pistol shot 610 when it really shot 400.

ok i want to upgrade gthe spring to a mad bull120 & i want to know what it will chrono at. Which one should i use to get the exact reading

I have a chrono we can test the madbulls on.

My gun chrono's at 350 everytime which is what it does everywhere else.