For anyone who owns an older model of Air Arms S410 series rifle, you will probably be familiar with the magazine indexing post having a little bit of spring steel to turn the mag rotor.
I have had several of these break and others fail to fully index the mag in the past.
At some point relatively recently AA made an upgrade:
Old type on left, new style on the right.
I am currently working on an early S310 which, although in near pristine condition, has some issues that need sorting.
One issue was the indexing post was not fully rotating the magazine for each shot (the magazines are the early plastic rotor versions) this led to quite rough loading of the pellet, which combined with another issue on the rifle means accuracy is pretty non-existent.
Anyway tackling the indexing first I bought one of the new pattern indexing posts, oh my what a difference it makes, the magazine indexes fully every time and the whole loading process is just so much smoother.
If you have the old type post, based on my experience, this is a modestly priced upgrade that is well worth the cost.