Bullboss .25 Do Polymags fit in the mag....

I have tried a few of the h&n's with the heavier barracuda's working the best. They are long though and this tip might help with polymags but I have never tried the polymags. I put the mag flatside down on a flat surface like a table then load the mag. It keeps the tips from sticking out. I will say I just tried the jsb heavies today even though it was only 18 rds and wow much better groups especially at longer distances. Groups were much tighter out to 60 yds. I didn't measure the groups because my target was over water. All the H&N's lost stability past 60yds or so. 40 to 50 yds pretty spot on. 
Side by side the Barracudas skirts are long and slender while the JSB's were short and fat which might help stability. I'm no seasoned veteran but that is my experience with my .25 Bullboss. Hope it helps.