My spring isn't new, but the rifle has a low round count. I measured the spring with a steel ruler, that has metric as well as inch marked. The spring measured just a hair under 3/4 inch× 1/8 inch. The metric was more accurate at 2 cm. × 3 mm. Hope this helps. Anyone know if the10/22 spring would match? I've never put em beside each other, but they would be similar. Maybe?