The Astra Militarum Leman Russ Battle Tank is one of the most flexible kits in the 40k range. A single sprue set builds eight different turret variants, and the hull supports interchangeable sponsons and front weapons. Magnetizing it lets you field whichever pattern your list calls for without buying the kit eight times. Here is what to focus on.
Turret variants and sponson swaps
The turret is where most of the value lives. Eight cannon options share the same turret housing, but the way each one mounts differs. A few drop in cleanly; others need the turret split so the breech and trunnions can be swapped behind the mantlet. Plan the build around being able to open the turret cleanly so you are not gluing yourself out of options later.
The standard battle cannon is the default loadout and uses a mantlet-mounted barrel. Magnetize the barrel at the mantlet so you can switch between this and the other long-barrelled variants. The Vanquisher cannon shares the same mounting style and can be swapped at the mantlet without opening the turret. The Eradicator nova cannon uses a shorter barrel with a distinctive muzzle and also fits the same mantlet point, so a single magnet location handles all three.
The Demolisher siege cannon uses its own short, heavy barrel and slides in at the mantlet as well, making it a clean magnet swap with no turret surgery. Together with the Vanquisher, this is the easiest of the eight to switch between on a magnetized hull.
The Punisher gatling cannon, Exterminator autocannon, Executioner plasma cannon and Annihilator twin lascannon are different. Each has its own breech assembly that sits inside the turret, not just a barrel that pokes out the front. To swap between these and the cannon variants, the turret top needs to lift off so the breech can be exchanged. Build the turret so the upper and lower halves meet on a clean seam and place a pair of magnets at the join. That gives you a turret you can open whenever you want to change the gun.
Sponsons are simpler. The hull has fixed mounting points on each side, and the kit offers heavy bolters, heavy flamers, multi-meltas, plasma cannons and lascannons. Magnetize the sponson weapon at the mount point on each side so you can rotate through all five options without rebuilding the sponson box. Do the same for the hull-front weapon, where heavy bolter, heavy flamer and lascannon options share a single mounting plug.
More Astra Militarum siblings
If you are working through a Guard armoured fist, the Krieg Artillery Team Magnetization Kit covers the Death Korps Heavy Artillery Team weapon swaps and pairs naturally with a magnetized Leman Russ company.