Bolt Action/Semi Automatic Comparsion

[[R-DEV]Drav]

Only if you were doing hit and runs on patrols, hoping to demoralise troops enough to send them home, as once you got in a fight with regular forces you'd be suppressed into submission I suspect.....

An assault on a military outpost with bolt action rifles for example would definitely void your life insurance......

[[MPN]Slouch2]

OK no-one is even close to the reason bolt-action sniper rifles are more accurate than semi-automatics.

The reason is headspacing. You get a much more consistent round seating with a bolt action as opposed to a recoil or gas operated bolt which relies purely on the kinetic energy of a spring, which does not provide a consistent force each and every time the weapon is cycled.

If the round is not seated positively within the chamber due to small slivers of brass inside the chamber, poor round alignment on extraction from the magazine or dimension changes due to weapon heating, the round will respond to a different 'harmonic' of the barrel.

Also, bolt actions feed rounds much more smoothly from the magazine which prevents the extractor claw of the bolt shaving slivers of brass off the base of the round, which can cause the changes mentioned above. In many automatic and semi-automatic weapons, the extractor claw is forced over the base of the round once inside the chamber. On a bolt action, the base of the round slips up and under the extractor claw during feeding, preventing any damage to the round itself. If you ever get the chance to look inside an M249 SAW after a few hundred rounds have been fired through it, you will see small shavings of brass inside, much like the wood shavings you would find on the floor of a carpenters workshop.

In terms of using a bolt action as weapon for CQB, well it comes down to a simple matter of firepower- which weapon is going to be able to put down more rounds in a given time. Accuracy in this case does not matter as much as it would to a sniper, where the sliver of brass mentioned above can change the point of impact by more than a meter at ranges over 700 meters.

[hiberNative]

interesting post, [MPN]Slouch2. i believe i have a learned :3

[[MPN]Slouch2]

You're very welcome

[[R-MOD]KP]

I think this man has just raised the bar for well-written posts, gentlemen. Bravo!

[[R-CON]nedlands1]

I suppose the mentality with a bolt action rifle is that you've got to make your shot count. With a semi-auto/fully-auto weapon you may have the luxury of a quick follow up shot.

[[R-DEV]Drav]

Although it doesent help these guys at all......

eeek

[Pariel]

Originally Posted by [MPN]Slouch2

OK no-one is even close to the reason bolt-action sniper rifles are more accurate than semi-automatics.

The reason is headspacing. You get a much more consistent round seating with a bolt action as opposed to a recoil or gas operated bolt which relies purely on the kinetic energy of a spring, which does not provide a consistent force each and every time the weapon is cycled.

If the round is not seated positively within the chamber due to small slivers of brass inside the chamber, poor round alignment on extraction from the magazine or dimension changes due to weapon heating, the round will respond to a different 'harmonic' of the barrel.

Also, bolt actions feed rounds much more smoothly from the magazine which prevents the extractor claw of the bolt shaving slivers of brass off the base of the round, which can cause the changes mentioned above. In many automatic and semi-automatic weapons, the extractor claw is forced over the base of the round once inside the chamber. On a bolt action, the base of the round slips up and under the extractor claw during feeding, preventing any damage to the round itself. If you ever get the chance to look inside an M249 SAW after a few hundred rounds have been fired through it, you will see small shavings of brass inside, much like the wood shavings you would find on the floor of a carpenters workshop.

In terms of using a bolt action as weapon for CQB, well it comes down to a simple matter of firepower- which weapon is going to be able to put down more rounds in a given time. Accuracy in this case does not matter as much as it would to a sniper, where the sliver of brass mentioned above can change the point of impact by more than a meter at ranges over 700 meters.

Why is fitting the extractor past the rim of the case necessary for semi-autos, and not for bolt-action weapons? Is there some sort of massive engineering problem which prevents the creation of a semi-automatic rifle that can chamber the round while simultaneously fitting the extractor?

[PR.Nato.Swordfish]

While Slouch beat me to it, headspacing has everything to do with it and more. When a spring weapon shoves a round in the chamber, think of it as literally shoving, it cuts into it and creates the shavings like he says. Personally, I feel its application. An SR-25 (semi auto gas bolt rifle) firing at a range of 500 M, and an M700 firing at the same range (M40/ M24 all variants), both are the same caliber, 7.62 or.308, same grainage, usually around 175 grains for the NATO rounds, will hit the same at that range. Now, on the flip side, say an enemy squad was coming around to hunt you. You fire your weapon, and the semi auto gun would give your position away...why? Cause it would spit the casing out whereas a bolt gun you can control the extraction of the casing after the shot is taken. Also with a bolt gun the recoil can mess with your follow through to a small degree, and at the longer ranges it will whack your shot.

I personally preferred the M40-series, great weapon, and if I ever had to worry about CQB, thats the reason we carried an M16A4 around with us and plenty of magazines. Basically gentlemen, it all boils down to application and how bad you want to remain hidden. Personally, I prefer bolt guns, but again, Ill use anything.

[galzohar]

That's what they teach in sniper course here and what logical application of physics would tell you:

- Higher velocity, since no gasses go back to cycle the weapon. This is probably by far the most significant factor in accuracy.

- Less moving parts - in semi-auto rifles the weapon necessarily starts cycling before the bullet leaves the barrel, which means more things that need to move in the exact same way every shot.

The other stuff may factor in too, some more and some less, though I doubt it would make the "1 meter at 700 meters" difference when you consider the fact there are semi-auto sniper rifles out there capable of hitting targets at 700 meters (M82 for example, though it is 0.5").

Overall, though, semi-automatic rifles, especially semi-automatic sniper rifles, can achieve awesome accuracy, just a bit less amazing than bolt-action rifles. Even an M16/M4 will hit a target at 300m rather easily when properly aimed while prone. Give it a bipod and it becomes quite easy to hit a target at 300m, a trained marksman should be able to have 100% hit ratio on a stationary "waist-and-up" target. An M24 sniper though should have 100% hit ratio for much longer ranges, and the main reason to miss is wrong wind/range estimations.