contradicting yields with butane extraction.

When you make bho do you shoot can after can as fast as possible or is it better to let it drain and then shoot more in after the dripping slows?

I've tried both methods and have had random results. My theory is that since i didn't use the same shake for each method the yields greatly differed(2-3g difference per run sometimes more/less). The extraction tube im using is about 2 ft by 2 inches. Any feedback will be appreciated. Thanks.

i always let it drip good about every half can.

I guess to be more specific on whats happening when i shoot it all fast it seems to drip out faster than its extacting. I did about 2 cans in 1 pyrex and then did the same thing in a different one and got the same yield from both. I then decided to do the same thing all at once into one, ending up getting 1/2 the amount.