The K31 straight-pull is criminally underrated—and I'll die on this hill

Well, you've got the provenance part right, and that's where I'll meet you halfway. My grandfather brought one back from '45—still has the original arsenal marks, never been refinished, and it sits in the cabinet exactly like it came over. That rifle's got a story, and keeping it that way *is* the point.

But here's what I'll push back on: I watched my cousin get bit by the "sub-$500 shooter" K31 idea about eight years back. Bought one, all excited about that trigger you're talking about. Shot maybe thirty rounds through it before he noticed the bolt was getting sticky. Turns out when you're buying a rifle that old for that price, you don't always know what headspace you're inheriting. He had to send it to a smith, and by the time he was done, he'd spent what he could've put toward a modern .308 that would do everything better and shoot ammo he could find at any box store.

I'm not saying don't buy K31s. I'm saying if you're actually going to *shoot* one, not just wall-hang it, you need to know what you've got before the first round goes downrange. Provenance and condition aren't the same thing on a seventy-year-old rifle, and one trip to a gunsmith can eat your whole savings on that deal.

Keep the ones worth keeping. Shoot the ones that are actually safe. Know the difference.

Hollerpatch is describing exactly what I see on the bench maybe twice a month. Before I'd call any K31 a shooter, though, I need to know what we're actually working with.

Here's the diagnostic piece: when you pick up one of these, the first thing I do is chamber a go-gauge and a no-go-gauge. If the bolt closes on the no-go, you've already got a problem before we even talk about firing it. Headspace creep on a rifle that age isn't rare—it's *expected*. The Swiss built them well, but "well" doesn't mean "frozen in time."

Second check is extractor tension. Grab the rim of a dummy round with the bolt closed and try to wobble it. Loose extractor means the round isn't seated predictably in the chamber, and that cascades into everything downstream—ignition timing, shot-to-shot variance, and in a worst case, a round that doesn't extract cleanly and jams the action.

Third is the throat. Measure it. A worn or pitted throat will compress your groups and mask whether you actually have a good rifle or just a rifle that shoots okay *today*.

Your cousin's sticky bolt, @hollerpatch? That usually traces back to one of those three, or a combination. A smith's diagnostic—not the work itself, just the checkup—costs $40–60 and tells you whether you're looking at a $30 fix or a $300 rebuild before you're $500 in the hole.

So the question for anyone considering the buy: are you willing to get it checked first? Because a K31 with a known headspace and tight extractor is legitimately nice. An unknown one is a gamble.

Shop.rat nailed the diagnostic sequence. That's the right starting point.

But let's be clear about what we're actually evaluating here: a K31 isn't a precision rifle. The trigger is genuinely good—better than contemporary mil-spec stuff by a meaningful margin. That part holds up. But the platform itself has hard limits.

Straight-pull action doesn't buy you precision. It buys you *speed without position shift*. Those are different things. The bolt geometry, the stock ergonomics, the sights—none of that was designed for sub-MOA work at distance. Swiss military doctrine didn't require it. The rifle reflects that.

If you're chasing precision—consistent, verifiable, repeatable sub-MOA—you need a rifle that was *built* for that threshold, not one retrofitted with handloads and hope. A K31 with a pristine headspace and tight extractor will shoot better than a neglected one. But "better" and "precise" aren't the same word.

Trigger quality matters. I'm not dismissing that. A 2.5-pound Swiss military pull will outperform a 6-pound Mosin pull every time, and that's measurable at the range. But trigger alone doesn't move a rifle from "competent mil-spec" to "precision platform."

Shop.rat's diagnostic is your actual decision point. If the headspace checks, extractor's tight, and the throat isn't shot, you've got a reliable shooter. That's worth something. Just know what you've got before you commit money or ammunition to proving it.

Okay, so here's where I'm going to nail down the actual measurement piece, because—and I'm not throwing shade at Rifleman.io, but this matters—we need to talk about *what* that trigger pull actually does in terms of shot consistency, not just what the rifle was "designed for."

The Swiss didn't adopt the K31 in 1931 and then just... leave it alone. They kept refining it through the '30s and '40s. The later production runs (especially post-1938 manufacture) show measurably tighter tolerances in the sear engagement. I've got calipers on about eight examples in the safe right now, and the variation between a 1931 early-run and a 1943 force-matched rebuild is *significant*—we're talking 0.003" variance in sear geometry.

That precision in the trigger translates to *actual, measurable repeatability* in the trigger break, which directly impacts group size at distance. Rifleman.io is right that the K31 isn't a target rifle. But they're wrong that the trigger is just "good compared to a Mosin." That 2.5-pound pull on a well-maintained example will give you break consistency within 2 ounces shot to shot. That's *better* than plenty of hunting rifles made in the 1950s and 1960s.

Shop.rat's diagnostic is the prerequisite—headspace, extractor, throat condition. Don't skip that. But once you've got a clean example? That trigger is doing actual work toward precision. It's not a match trigger, but it's not a compromise either. It's a purpose-built military trigger that happens to be really, really good at what it does.

The K31 is what it is: a robust, fine-shooting bolt gun with better ergonomics than its peers and a trigger that will make you a better shot. Know the headspace. Then shoot it.