Marlin Rimfire Extended-Capacity Magazines: 556-XT10 and 556-XT15 Explained

ARM doesn't sell magazine extension kits — there's no bolt-on body extension, spring kit, or floorplate swap in our lineup, and a generic kit that isn't matched to the magazine's original spring and feed lips is the single biggest cause of extended-magazine jams. If you want more capacity for a Marlin 780/25/20/80-pattern bolt-action rimfire, the reliable way to get it is a complete, factory-built extended-capacity magazine: the 556-XT15 (15 rounds) or the 556-XT10 (10 rounds), both built as one matched unit with the spring, follower, and feed lips engineered for the added capacity — not bolted onto a shorter body afterward.

Why a complete magazine beats a bolt-on extension

Adding capacity to a rimfire box magazine means lengthening the body and running a longer spring through more travel, and the follower has to be shaped to sit flush at the new capacity. Doing that correctly means engineering the spring, follower, and feed lips as one matched set — which is exactly how ARM builds the 556-XT15 and 556-XT10, rather than as a kit meant to be added to an existing 7-round magazine. Reusing a factory 7-round spring in a longer body, or mixing parts from different kits, is the most common cause of feeding failures in stretched magazines generally.

What the 556-XT15 and 556-XT10 fit

Both are compatible with Marlin Bolt Action Model 780/25 rifles, and the same models covered by the standard 7-round #71903 magazine: Marlin 80, 780, 20, 25 (including 80C, 80DL, 80E), Glenfield 20, 25, and 80G, JC Higgins 42 and 42DL, Foremost 20, and Revelation 105.

• 556-XT15 — 15 rounds of .22LR, black oxide steel. Due to state capacity restrictions, this magazine cannot ship to California, Connecticut, Hawaii, Maryland, Massachusetts, New Jersey, New York, Vermont, Oregon, Rhode Island, DC, or Washington.
• 556-XT10 — 10 rounds of .22LR, black oxide steel. A compliant-capacity option for shooters who want more capacity than the standard 7-round magazine but are in a state with a 10-round restriction.

Magazine capacity rules vary by state. We don’t give legal advice — check your state before you order anything above standard factory capacity on our magazine capacity laws by state page.

What to check on some Model 80-pattern rifles

On some Model 80-series rifles, the rivet used in the magazine well can stick out slightly and prevent the magazine from fully engaging. If you notice the magazine isn't seating flush, the fix is to grind down the rivet slightly or trim the bottom magazine plate so the rivet clears — not to force the magazine home. If your existing 7-round magazine already sits loose with noticeable front-to-back movement, our Clip-Rite fit fix addresses that looseness on Model 80-series rifles and is compatible with the 71903, 556-XT15, and 556-XT10 magazines.

Getting the most out of extra capacity

More capacity means fewer reloads during an active hunting stand or a range drill, but it also means a longer magazine hanging below the stock — plan for that on a bench rest. Function-test any new magazine with a few dummy rounds cycled by hand before you trust it in the field, the same way you would any new part.

Which magazine do you need?

• Standard 7-round (all states): Marlin 780/25/20/80 7-Round Magazine (#71903)
• 10-round, compliant-capacity: Marlin 556-XT10 Bolt Action Magazine
• 15-round, maximum capacity (check your state first): Marlin 556-XT15 Bolt Action Magazine
• Loose factory magazine? Clip-Rite Magazine Fit Fix for Model 80-series rifles
• Browse everything: Marlin .22 Cal. Magazines collection or the Marlin Magazine Guide

Frequently asked questions

Does ARM sell a magazine extension kit for Marlin rimfire rifles?

No. We don't sell bolt-on extension kits. For more capacity on a 780/25/20/80-pattern bolt-action, we build the 556-XT10 (10 rounds) and 556-XT15 (15 rounds) as complete, matched magazines.

Can I ship the 15-round 556-XT15 to any state?

No. Due to state capacity restrictions, it cannot ship to California, Connecticut, Hawaii, Maryland, Massachusetts, New Jersey, New York, Vermont, Oregon, Rhode Island, DC, or Washington. The 556-XT10 is the 10-round compliant option.

Which rifles fit the 556-XT10 and 556-XT15?

The same models as the standard 7-round #71903 magazine: Marlin 80, 780, 20, 25 (including 80C, 80DL, 80E), Glenfield 20/25/80G, JC Higgins 42/42DL, Foremost 20, and Revelation 105.

My magazine feels loose in the well — is that a spring problem?

On some Model 80-series rifles, a rivet in the well can prevent full engagement, or the fit can simply run loose. Our Clip-Rite fit fix addresses looseness on Model 80-series rifles and is compatible with the 71903, 556-XT10, and 556-XT15 magazines.

Is a 10-round or 15-round magazine legal in my state?

Magazine capacity laws vary by state. We don't provide legal advice — check our magazine capacity laws by state page and verify current law directly with your state before ordering.

Skip the generic extension kit and order the complete magazine built for the capacity you want — the spring, follower, and feed lips arrive matched and ready to load.

Buying for a shop, a range, or more than one rifle? See our wholesale purchasing terms for volume pricing.