![]() Lubing a casing plummets that friction, and can increase pressures on the bolt lugs by up to 40%, depending on cartridge design.īore, Chamber, and Ramps - Never lubricate, except for storage or rust prevention, and even then only use oil. Casing brass, however, being soft, first expands against the chamber walls during firing, serving to seal off the chamber from expanding gasses, and also creates a significant amount of friction against the chamber wall that would otherwise be directed into the locking lugs of the bolt. When ignited, the gasses treat the bullet and casing equally, trying to turn each into a projectile out either end of the barrel. Lube on ammo can dramatically increase the pressure on locking lugs. Lube on ammo will virtually guarantee sand sticks to it, and cause a malfunction in the chamber during chambering if sufficient enough. But by adding just a little lube, that sand can add up enough friction to keep the ammo from moving fast enough up the mag. But if wet, it may stay in place and accumulate, adding enough friction to overcome the narrow window of reliability.ĭifferent geometries and energies mean different friction experiences - the fast speed of an action, combined with tight, long geometries, can allow a single piece of sand in an action to cause binding, while slower mag followers with shorter and looser friction-surface geometries may not experience such binding, and can handle a little dry sand. Being of looser tolerances, if dry, sand will tend to want to drop below the follower during cycling. In complete opposite of the action, mags run best dry, and worst wet, and have a very narrow window of reliability between energy and friction - the energies of the springs compared to the resistance of the ammo and follower are narrow, because if too powerful the action would have a hard time stripping each round during cycling, and too light the springs wouldn't move the ammo fast enough. If your 1911 is in 10mm, 40, or another high-pressure cartridge, don't lube it, unless it is finicky. Consequently, if you want maximum reliability, keep that radius well-lubed, to keep the slide velocity as high as it was engineered to go. 45 or 9mm builds, as the bigger issue for them is generally the moving parts going too slowly, especially with the addition of a little friction contaminant. 40cal and 10mm 1911s, as these high-pressure rounds are notorious for battering slides right out of spec from excessive slide velocity, in as little as 1000 rounds – that’s how much energy can be dissipated out of the moving parts just by this little radius. It’s the same as with any lever: the further back you get, the more leverage you have and less energy you use – the closer to the fulcrum, the more difficulty you have.Ĭustom pistol smiths often use an extremely sharp firing pin stop when building. The sharper that radius is towards a square, 90 degrees, the less leverage the slide has in cocking the hammer back, as the contact point on that radius moves closer to the hammer’s pivot point the sharper it gets. This is a key hidden source of both friction and mechanical disadvantage, and it can absorb an immense amount of the energy being transferred into the slide by the shot. In this photo you can see the firing-pin stop slightly removed from its recess, to show the curve of the radius which the hammer is cocked against.
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