JJ typing, so you have a bunch of sponson weapons and you want to use them. Certainly don't want to glue them into their mountings. Variety is the spice of life. Fortunately as Mike and Lane said, you don't need magnets for leman russ sponson weapons. Should only have to base the male end of the sponson weapon and it will stay put.
Paint stick from DIY store
|First problem: attaching these weapons to this part of the sprue. Poster tac or paper clips.|
|Since I almost have a fetish for pinning, it is! Conveniently there are enough plastic circles for the ten weapons.|
|Little drilling and inserting paper clips and its a weapon mount.|
|Drill through the end of the weapon people won't be seeing.|
|Little splash of colour...|
|and you're done! Can paint all sponson weapons like this in less than 30 mins.|
Extra step: added a little bit of detail per client request.