Abstract: In a telescopically extensible ammunition magazine for a firearm or similar device in which the rounds of ammunition are biased toward the firing chamber, by a coil spring, bent leaf spring or similar resilient device, a tensioning cord partially compresses a section of the spring preventing full extension of that section and causing the spring to snake and rub against the inside of the magazine or magazine assembly. The partially snaking spring is allowed to frictionally and incrementally travel within the magazine during reloading keeping each round properly aligned as each one is inserted. The extended length of the spring is selected to provide the minimum spring extension needed to feed the final unit of ammunition to the firing chamber when the magazine is collapsed to its minimum length. Ammunition can thus be conveniently loaded without having to compress the spring; yet the full strength of the spring is available to bias the rounds towards the firing chamber.