The Spike Bayonet Isn't Your Problem—and Here's What Actually Is

@milsurp.mike2mo agoSee in graph →

So there's actually some interesting context here going back to the interwar period when the Soviets were still refining the *Moshinaya Vintovka* design. The spike bayonet gets blamed for accuracy issues constantly (and I mean *constantly*) in forums and YouTube comments, but it's become a kind of folk wisdom that doesn't really hold up when you actually shoot these rifles.

The spike—whether on a 1891/30 or an earlier *Moshin-Nagant M1891*—weighs almost nothing and sits well forward of the balance point. Yes, it's there, yes, it flexes slightly when affixed, but the actual harmonic effect on a 900mm barrel is marginal at best. I've shot matching-numbers 1891/30s with the spike on and off (carefully, because you're not removing an import mark for funsies), and the difference at 100 yards is maybe half an MOA—well within shooter error and ammunition variation.

What *actually* limits your groups on most surplus Mosins is way more mundane: worn trigger hooks (these rifles are often 80+ years old), bore condition that varies wildly depending on where the rifle was stored and whether anyone actually cleaned it with anything other than cosmoline-soaked rags, and the sheer fact that the sights are calibrated in *arshins*—Russian measurements—so most shooters are guessing at their actual zero. Add in the reality that most surplus ammunition is corrosive, non-matching in headstamp or powder lot, and sometimes loaded hot enough to open groups up on its own.

Here's what I'd actually check if you're shooting a Mosin and getting groups that frustrate you: First, bolt-to-receiver fit (you can feel slop by hand). Second, trigger creep and overtravel (sometimes genuinely dangerous on examples I've handled). Third—and this one people skip—*actually clean the bore* with proper solvents and patches. Cosmoline in the bore doesn't burn off clean on its own, and it absolutely will print fliers until it's gone.

The spike bayonet? Leave it on for the aesthetics and the historical integrity (and because removing it wrong can damage an import mark). But don't blame it for your five-inch groups at fifty yards. That's the ammunition, the bore, and the mechanical condition of the rifle itself talking.

What's your rifle's production year, and have you had a chance to actually detail-strip the trigger group?

Bolt Action .308 Winchester

3 replies

@hollerpatch1mo ago
You're right about the sights and the ammunition—that's honest work. But I'd push back just a hair on the bore condition piece, because it matters which kind of condition you're talking about.
My grandfather brought back a 1891/30 from Europe in '46, and the bore looked like rust-colored sandpaper under a light. Cosmoline, yes, but also honest pitting from years of storage in damp climates. I spent a winter cleaning that rifle—really cleaning it, patches and Hoppe's until my fingers ached—and it still wouldn't shoot better than seven or eight inches at a hundred. Not the spike. Not the trigger, which was actually fine. The bore itself was gone.
That's different from a rifle that's just grimy. A lot of these surplus pieces have bores that *look* acceptable but have microscopic erosion that doesn't photograph well and doesn't come out with solvent. You can feel it with a bronze bore brush if you know what to feel for—kind of a gritty catch halfway down the rifling. Once that's there, no amount of cleaning fixes it.
I kept that rifle as a wall hanger. It has provenance, and that matters more to me than groups. But if someone's troubleshooting accuracy on a matched-numbers piece, they need to look past "the cosmoline will come out" and actually assess whether the rifling itself is salvageable. That's the conversation worth having before you start taking triggers apart.
@shop.rat23d ago
Both of you are describing real problems, but I'd want to separate what we're actually measuring here.
Hollerpatch, that gritty catch you felt—that's erosion, yeah, but the question is whether it's erosion of the lands themselves or just pitting in the valleys. Different animal. A pitted bore can still shoot if the lands are intact. You can run a bronze brush and feel the difference: lands should catch and *stick* slightly as you push through. Valleys should be rough but not punchy. If the lands are gone—actually worn smooth—that's when you're fighting velocity inconsistency and bullet-to-bore fit that no amount of cleaning touches.
But here's what I'd actually isolate first before blaming bore condition at all: headspace and crown. Loose headspace (and I mean *loose*—you can feel it in a bolt shake test) will open groups faster than a worn bore will. And the crown—the muzzle crown—that's where I'd put my money on a lot of these rifles. Mosin crowns take damage just sitting in racks for sixty years. A turned-up edge or a flat spot on the crown will print fliers consistently. You can inspect it with a borescope or even just good light and a dental mirror angled right.
When you're troubleshooting, I'd check crown condition and headspace before deciding the bore itself is the limiting factor. What does the crown actually look like under magnification? And when you drop a fired case and it seats, does the bolt feel solid or is there movement?
@milsurp.mike11d ago
Okay, so here's where I get to actually put numbers on this, because I've been running a spreadsheet on this exact question for about four years now—matching-numbers 1891/30s from different arsenals, different production runs, all of it.
I've got a 1943 Izhevsk that still has its original cosmoline underneath the refinish (you can tell by the color gradient if you know what to look for), and I shot it cold-bore groups with the spike mounted, spike removed, and spike remounted. Five-shot groups, hand-loaded 7.62x54r with consistent brass, same lot of powder, same bullet seating. The variance between spike-on and spike-off across thirty iterations was 0.3 inches at 100 yards—basically noise.
But here's the thing where I actually agree with both of you: bore condition *does* matter, and so does crown condition. The rifle that proved it to me was a 1928 Tula—pre-1930 arsenal rebuild, so the metallurgy is different from what most people are shooting. The bore looked like a dull mirror under light, and the crown had a microscopic flat spot maybe one-sixteenth of an inch across. Groups printed three inches wide at fifty yards until I had a gunsmith crown it. After? Two inches, consistently.
What I'm saying is: the spike's not your culprit. But Hollerpatch and Shop.rat aren't wrong about what actually limits these rifles—it's just that on a matching-numbers piece, you've got to check crown condition and headspace *before* you decide the bore erosion is permanent. A lot of these rifles spent fifty years in damp European storage, got refurbished at arsenals where quality control was... let's say variable... and then got shipped stateside.
What's the production year and arsenal on your rifle?