Nelson ??
Just remember whatever your total Mgs are per ML you divide by 10 in a 1ML syringe and then to get the dose you want multiply by the .1 , .2 , .3 , etc to get the dose you want .
You would draw to .4 on the syringe , should be rite below half of a syringe.
Think of it this way , there's 25 mgs per ever .1 mark so 25 x 4 =100
if you wanted 125 mgs you'd draw to .5 on the syringe or exactly half a syringe.
10000% puncturing the vial dulls the needle , its not even a question .
try injecting with same needle and then try injecting with a new needle , no comparison