DMK
Member
I've noticed that my 27" barreled Finnish M/39 Mosin-Nagant groups much better with ammo in the 140gr. range, but my 20" barreled 91/59 Mosin carbine is the opposite, grouping better with ammo in the heavier 180gr. range.
These two are my most accurate Mosins, but my other M/39 and my 1938 carbine also seem to follow the same pattern.
From what I understand, the twist rate is the same on all of these. What other factors could contribute to a rifle preferring heavier or lighter ammo? Is the shorter barrel a big factor? Perhaps better tolerances on the Finn rifles over the Russians?
These two are my most accurate Mosins, but my other M/39 and my 1938 carbine also seem to follow the same pattern.
From what I understand, the twist rate is the same on all of these. What other factors could contribute to a rifle preferring heavier or lighter ammo? Is the shorter barrel a big factor? Perhaps better tolerances on the Finn rifles over the Russians?
