Wolverine MTW BB Retention Spring — Gen 3 Feed Tube

A feed tube has to hold a column of BBs ready without letting them drift back out when the rifle is tipped or jolted. That retention is the spring’s job, and when it tires the symptom is not a dead rifle but an inconsistent one — the odd dry cycle, or rounds going missing between the magazine and the chamber.

It is a thin piece of wire under constant light load, which is exactly the sort of component that fatigues slowly rather than breaking cleanly. People chase magazines and buckings for months before looking at it.

This is the Wolverine part for the Gen 3 tube. It is cheap enough that replacing it on suspicion is a reasonable diagnostic step while the upper is already open.

Specifications

Good to know before you buy

Confirm your feed tube generation first. Gen 3 arrived in 2023, and which tube an upper takes depends on the year it was built, so check before ordering rather than after.

Fit it while something else is apart. Getting to it means opening the upper, so pair the job with a bucking change or a hop service instead of doing it on its own.

Frequently asked questions

What goes wrong when this wears?
Retention gets weaker, so BBs can creep back down the tube. That shows up as occasional dry cycles rather than an outright stoppage, which is why it is easy to misdiagnose.

Does it come with the tube?
Not here. This is the spring by itself; the feed tube is listed separately.

Will it suit an older MTW?
It is the Gen 3 part. Earlier tubes are built differently, so tell us your rifle and we will confirm which one you need.

Is this the same as the hop spring?
No. The hop spring sits in the hop unit and sets pressure on the bucking; this one works in the feed path and holds BBs ready.