2011 Magazine Spring Comparison: Tripp Research, Wolff & Stock Springs for USPSA Limited & Open (2026)

2011 magazines fail two ways: they bind under recoil and the slide locks back early. Both problems trace back to the spring, not the tube, the follower, or the base pad. This guide compares Tripp Research, Wolff Gunsprings, and factory-OEM 2011 magazine springs across the lengths that matter for USPSA Limited and Open shooters — including which spring pairs with which base-pad length so you actually load to capacity instead of fighting the last two rounds in.

Why magazine spring choice decides 2011 reliability

A 2011 magazine is a stack of variables. The tube length sets the maximum capacity, the base pad converts that tube into a 140 mm or 170 mm legal column, the follower presents rounds to the feed lips, and the spring does all the work to push them. When competitors talk about a "tuned" 2011 magazine, they almost always mean a spring change.

The two failure modes you see on the timer are direct symptoms of spring mismatch. Failure to feed on the last 1–3 rounds means the spring has lost compression at the bottom of the stack — usually a too-short or too-light spring. Slide-stop pop-up under recoil is the opposite — a too-stiff spring or a follower-tilt issue that bumps the slide stop off the round. The right spring for a given tube and base-pad combination eliminates both.

USPSA Limited and Open division shooters care about this disproportionately because they run the longest stacks the rules allow. A 140 mm Limited tube is fine on a stock spring at 17 rounds in 9 mm, but the same gun pushed to 20 rounds in a 170 mm Open tube needs a longer, slightly heavier spring or it will short-stroke before the last quarter of the stack.

The 2011 magazine spring market: who makes what

Three sources cover virtually all 2011 magazine springs in competition use today: Tripp Research, Wolff Gunsprings, and factory OEM (the springs that ship in Staccato, STI, Atlas, Bul Armory, and Springer Precision tubes from the factory).

Tripp Research — the modular system

Tripp's spring line is built around a coding system: the first two digits are the spring length in inches, the second two digits identify the wire diameter and follower compatibility. The four most-used codes for 9 mm 2011 magazines are MS-12C042 (12" spring, .042 wire, fits 140 mm tubes), MS-13C042 (slightly longer, same wire), MS-14C048 (14" spring, heavier .048 wire, for 170 mm tubes), and MS-17C048 (17" spring for the deepest 170 mm Open builds with low-friction followers).

The advantage of the Tripp system is that the spring length and wire diameter are matched to a specific tube length and follower style. The disadvantage is choice paralysis — there is no single right answer; the right Tripp spring depends on the exact tube + follower + base-pad stack you have built.

Wolff Gunsprings — heavier, simpler

Wolff offers two practical 2011 spring options for competition use: a "standard" extra-power spring and a "ten-percent extra-power" version. Wolff springs are heavier on average than Tripp springs of the same nominal length, which makes them more forgiving on dirty magazines or under-lubricated tubes — and harder on the slide stop if your follower isn't dialled in.

Wolff is the right choice if you want one spring that works across multiple tubes you already own and you are willing to accept slightly more felt compression at the top of the stack to gain reliability at the bottom.

Factory OEM — the baseline

Stock springs from Staccato, STI, and Bul Armory are tuned for the tube and base pad they ship with. They are not bad — they are simply the conservative middle ground. If your gun runs reliably at the rated capacity on factory springs, leave them alone until they take a permanent set (typically 5,000–10,000 rounds) and replace with the same spring length when the time comes. Most failures attributed to "OEM springs" are actually springs that have been compressed under load for years and need replacement, not springs that were the wrong specification on day one.

Spring selection by USPSA division and base pad length

This is where most 2011 owners go wrong. The base pad and the spring are a system — the wrong spring inside the right base pad will short-stroke, and the right spring in the wrong base pad will bind.

For USPSA Limited and IPSC Standard (140 mm column maximum), pair a Tripp MS-12C042 or MS-13C042 with a 140 mm-class double-stack base pad. The Boss Components 2011 Brass Double Stack Magazine Base Pad — IPSC Standard is the legal-length brass option for this division and adds enough nose weight to settle reload geometry without pushing past 140 mm. The aluminium equivalent — the 2011 Aluminium Double Stack Magazine Base Pad — is the choice when you are minimising magazine weight for splits or carrying eight on the belt.

For USPSA Open (170 mm column maximum) the spring requirement steps up. Use a Tripp MS-14C048 or MS-17C048 inside a long-format base pad. Boss's 2011 Aluminium Double Stack Open Long Magazine Base Pad is the 170 mm body that pairs with these springs — it is dimensioned so the heavier .048 wire spring still travels its full stroke without coil-binding when the magazine is fully loaded. Drop a shorter Limited-length spring into a 170 mm tube and the last 4–5 rounds will short-stroke; drop a 17" Open spring into a 140 mm tube and you will get coil-bind that stalls the bolt cycle.

For 1911 single-stack USPSA Single Stack and Limited 10 builds, the equation is simpler — Wolff extra-power 8-round and 10-round springs cover the field. Pair them with a base pad sized to your magazine tube. Boss's 1911 Brass Magazine Base Pad — Multi-Fit is the brass option that fits the three most common single-stack tubes (Metalform, Dawson Precision, Tripp Research). The 1911 Mec-Gar / Bul Armory Aluminium Base Pad covers Mec-Gar and Bul Armory tubes specifically.

2011 Aluminium Double Stack Open Long Magazine Base Pad for 170mm USPSA Open division Tripp Research springs

Spring + base pad pairing matrix

Tube Length USPSA Division Recommended Spring BC Base Pad Typical 9 mm Capacity
126 mm (factory) Production / Carry Optics OEM Staccato/STI or Tripp MS-12C042 Factory or thin aluminium 17
140 mm (Limited) USPSA Limited / IPSC Standard Tripp MS-13C042 or Wolff XP 2011 Brass Double Stack — IPSC Standard 20
140 mm (Limited, light) USPSA Limited Tripp MS-13C042 2011 Aluminium Double Stack 20
170 mm (Open) USPSA Open Tripp MS-14C048 or MS-17C048 2011 Aluminium Double Stack Open Long 27–29
1911 single-stack 8-rd USPSA Single Stack Wolff XP 8-rd 1911 Brass Multi-Fit 8
1911 single-stack 10-rd USPSA Limited 10 Wolff XP 10-rd 1911 Mec-Gar / Bul Armory Brass 10

Followers — the variable nobody talks about

Springs only work as well as the follower lets them. Three follower types dominate 2011 magazines: factory plastic, Grams 9-coil-compatible aluminium, and CMC anti-tilt. Each prefers a different spring.

Factory plastic followers are forgiving — they tolerate Tripp, Wolff, or OEM springs. Grams aluminium followers were designed around the Tripp MS-series and pair best with .042 wire on Limited tubes and .048 wire on Open tubes. CMC anti-tilt followers prefer slightly stiffer springs because the wider bearing surface adds friction. If you are running a follower upgrade and getting failures-to-feed in the last two rounds, your spring is almost certainly not matched to the follower — change spring before changing tubes.

2011 Brass Double Stack Magazine Base Pad IPSC Standard 140mm USPSA Limited

Cross-platform compatibility: Staccato, STI, Atlas, Bul Armory, Springer

The good news for 2011 owners is that the magazine spring market is largely platform-agnostic at the tube level. Tripp and Wolff springs that fit STI/Staccato 140 mm tubes also fit Atlas Gunworks, Bul Armory SAS II, and most Springer Precision tubes — because the tube ID is standardised at .380" (9.65 mm).

Three exceptions worth knowing: Atlas Chaos tubes have slightly different wall thickness — Tripp MS-13C042 fits but test in dry-fire first. Bul Armory SAS II Ultralight tubes are STI-dimensional but the factory follower tilts at high round counts; pair with Grams or CMC. Springer Precision 170 mm tubes prefer MS-17C048 over MS-14C048 due to heavier follower bearing surface.

How long do 2011 magazine springs last?

Round counts are misleading. The number that matters is compression hours — how long the spring has been held under load, fully compressed. A 2011 magazine left loaded to 20 rounds for six months will lose more spring tension than the same magazine cycled 5,000 rounds and stored empty.

The practical rule: if you load magazines for matches and dump them empty after the stage, your springs will last 8,000–12,000 rounds. If you leave magazines loaded in a range bag between sessions, replace springs every 18–24 months regardless of round count. Springs are cheap. Match DQs from a feed failure are not.

Complete your 2011 magazine setup

A correctly tuned 2011 magazine is a system of four matched parts: tube, spring, follower, and base pad. If you are starting fresh or rebuilding a problem magazine, replace them as a set rather than hoping one new component will fix a stack of legacy mismatches.

2011 Aluminium Double Stack Magazine Base Pad USPSA Limited 140mm Tripp Wolff spring compatible

Frequently asked questions

Should I use Tripp Research or Wolff springs in my 2011?

Use Tripp if you are building around a specific tube and follower and want the spring tuned to that combination. Use Wolff if you want one spring family that works across multiple 2011 tubes you already own. Both are reliable in competition.

What spring goes in a 140 mm 2011 Limited magazine?

The Tripp MS-13C042 (.042 wire, 13" length) is the standard recommendation for 140 mm tubes loaded to 20 rounds in 9 mm. The Wolff extra-power equivalent is also a valid choice if you prefer a slightly heavier spring.

What spring goes in a 170 mm 2011 Open magazine?

Use a Tripp MS-14C048 for typical 27-round Open builds, or step up to the MS-17C048 if you are running deeper-stack 29-round configurations or stiff anti-tilt followers. Both pair with Boss's 170 mm aluminium long base pad.

How often should I replace 2011 magazine springs?

Replace every 18–24 months if magazines are stored loaded, or every 8,000–12,000 rounds if magazines are stored empty between range sessions. Cheaper than a stage DQ.

Will a Tripp spring fit my Staccato magazine?

Yes. Staccato 140 mm and 170 mm tubes use the same internal dimensions as STI tubes, so Tripp MS-series springs drop in directly. Verify follower clearance with the spring fully compressed before live fire.

Do I need to change my follower when I change my spring?

Not always — but if you are switching from OEM to Tripp or Wolff, also upgrade to a Grams 9-coil-compatible or CMC anti-tilt follower. The combination eliminates the last-round nose-dive that causes most 2011 feed failures in dirty magazines.

Why does my 2011 slide lock back early?

Three causes, in order: spring too stiff (replace with a lighter wire diameter), follower tilt bumping the slide stop (upgrade to anti-tilt follower), or your slide stop is sitting too proud of the frame. Diagnose by loading a single round in the magazine and watching whether the slide stops with the round still in the tube.

Conclusion: spring choice is the cheapest reliability upgrade on a 2011

Tubes, frames, and barrels get the attention but it is the magazine spring that decides whether your gun runs to slide-lock at the rated capacity. Match the spring length and wire diameter to your tube length, pair it with the right base pad, run a follower that suits the spring, and replace the spring on a calendar — not just a round count. Boss Components builds the base pads that complete the system — the 170 mm Open long base pad and 140 mm Limited brass base pad are the two USPSA shooters reach for first.

Related reading

Back to IPSC