BX-25s in stock 10/22—what does the notebook say?

Question

I ran both mags through the same rifle for eight weeks, 200 rounds per session, same ammo lot, same conditions. Kept notes on every stoppage.

1. Factory 10-rounder: 2 failures to feed across 1,600 rounds. Both were light strikes on old CCI.
2. BX-25: 8 failures to feed, all in first 400 rounds. Then settled to 1–2 per 800 rounds after that.

The BX-25 had a break-in period. The feed lips were stiff out of the box. Once they relaxed, malfunction rate dropped near parity with the factory mag.

If you're loading a fresh BX-25 today, expect some friction the first 300–400 rounds. After that, I'd call it reliable for general practice. For precision work or a competition string, I still reach for the factory mag—fewer variables to isolate.

Are you seeing failures with a new BX-25 or an older one?

Ben Rourke · Answer

Good data. The break-in you're describing tracks with what I've seen across maybe 8,000 rounds split between BX-25s and factory 10-rounders in a few different 10/22s.

Your feed lip stiffness observation is the real story here. Magazines are stamped and formed, not precision-machined. The BX-25 uses a slightly different follower geometry than Ruger's factory mag—taller, narrower—so the lips come off the press with tighter tolerances. First 300–400 rounds is about right for them to settle. I've had two that needed closer to 500 before they stopped causing light strikes on marginal ammo.

Where I'd push back just slightly: the factory 10-rounder's 2 failures across 1,600 rounds probably tells you more about that CCI lot than about the mag itself. CCI's ignition variance used to be wider than it is now, and 10/22s are notoriously sensitive to primer seating depth. If you load the same mag with modern Federal or fresh CCI, you might not see those two stoppages repeat.

So my take: BX-25 is genuinely reliable *after break-in*. For someone buying today, expect to nurse it through the first few hundred rounds and swap to the factory mag if you need certainty right now. After that point, for general practice work, I'd trust it. Competition or precision strings—yeah, I'm still going factory.

Are you running the same round count on the factory mag in the newer rifle, or just the 10/22 you tested?

Leo Park · Answer

Ben's round count is solid, but the follower geometry detail needs precision here. Ruger's factory follower is a single-piece stamped steel with a 0.085" witness line tolerance on the feed lips—that's measured from the top of the follower to the inside of the formed lip. The BX-25 follower is polymer with a taller profile, roughly 0.095" at the same measurement point.

That 0.010" difference doesn't sound like much until you account for how it stacks with mag spring preload. The BX-25 spring is also slightly stiffer (measured at compressed height), which means the follower sits higher in the stack during loading. Higher follower position = shallower angle of attack on the feed lip when the round is being stripped. That's why you see failures in the first 300–400 rounds—the lips are being mechanically worked by the harder angle until they plastically deform down to a more forgiving geometry.

The factory mag avoids this because the follower bottoms out lower, so the round hits the lip at a steeper, more "forgiving" angle from the start. Stamped steel also work-hardens differently than polymer; there's less geometric change over time.

Other detail worth noting: polymer followers absorb solvents and oils. If you're cleaning the mag aggressively with degreaser, you can temporarily change its geometry by ~0.003" until it re-equilibrates. Not a failure mode, just a variable worth controlling if you're chasing precision.

Break-in reality holds. Just the mechanism is tolerances stacking, not the lips "relaxing" in the traditional sense.