Sniper rifles: bolt action vs. semi auto.

[KICK]

[QUOTE=kurt tank 152;2453960]well Chad, i said what i saw on history channel, and the guy was there giving details. can't remember his name, but he said something about his targets that i coudn't forget: "they thought that it was their lucky day. it wasn't!" i think he said that because he hit the guy on the third shot. i don't know, the .338 LM can reach 1 1/2 mile and kill?



FWIW a .22 can kill you at 1000 yards or farther, if it hits a vital spot.

FWIW a 50 cal can not kill you at 10 yards if it is a flesh wound.

[kurt tank 152]

[QUOTE=KICK;2459742]

Originally Posted by kurt tank 152

well Chad, i said what i saw on history channel, and the guy was there giving details. can't remember his name, but he said something about his targets that i coudn't forget: "they thought that it was their lucky day. it wasn't!" i think he said that because he hit the guy on the third shot. i don't know, the .338 LM can reach 1 1/2 mile and kill?



FWIW a .22 can kill you at 1000 yards or farther, if it hits a vital spot.

FWIW a 50 cal can not kill you at 10 yards if it is a flesh wound.

the .223 kill you if hit your eye at 1000 yards.

the temporary cavity of .50 cal on 20% ballistic gel at 50 yards is larger than the size of a human body torso. if you're hit by a .50 cal in your guts, is likely your body split in half. if hit an limb, it takes the limb out.

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All men can see these tactics whereby I conquer, but what none can see is the strategy out of which victory is evolved.
Sun Tzu

[johns624]

Bigger isn't always better. Sometimes the smaller, more portable, less bruising weapon can do the job just fine, or even better.

[kurt tank 152]

Originally Posted by johns624

Bigger isn't always better. Sometimes the smaller, more portable, less bruising weapon can do the job just fine, or even better.

yeah Johns, this is correct to many aspects of life but sniping. there's a difference between "bigger" and "effective". the smaller caliber for a serious sniper is the 7,62 NATO. 5,56 can be used, of course, if your target is closer than 400 yards. further than this it can kill, if hit a vital area. 7,62 hasn't this issue up to 1200 yards.

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Be extremely subtle, even to the point of formlessness. Be extremely mysterious, even to the point of soundlessness. Thereby you can be the director of the opponent's fate.
Sun Tzu

[Pruitt]

A lot would depend on the terrain you are in. I imagine spotters on a Sniper Team have taken along M-16's on occasion.

Pruitt

[Nichols]

Originally Posted by FTCS

To summarize the discussion so far I think the following points have been made.
Semi-Automatic
Pro:
1.Easier to maintain sight picture for re-engagement of same or different target.
2. Faster re-engagement of target or targets
Con:
2.There is some movement of the barrel prior to the projectile leaving the muzzle due to the cycling action of the bolt.
3. Projectile velocity loss due to design of gas recoil system.

Bolt Action
Pro:
1. No projectile velocity loss associated with semi-automatic
2. No barrel movement due to bolt action prior to projectile leaving the muzzle.
Con:
1. Re-engagement time greater that that of a semi-automatic

When it really comes down to it, it is the person behind the weapon that makes the difference. In the hands of a well trained and experienced shooter either weapon can and does accomplish the mission. I suspect that when it really comes down to it is personal preference and/or the environment that the sniper is working in is a major factor in weapon selection.

I don't fully buy off bolt movement effecting the auto over the manual. The bolts to both weapons are locked before the trigger is pulled.

I would add in that barrel harmonics also play a larger role and this may be what people are mistaking for bolt movement. A free floating barrel will pretty much keep the same harmonics; bolt action rifles generally have a free floating barrel all the way to the receiver. They do have 'free floating' barrels on many semi auto rifles but while the barrel may not be touching the stock.......the gas block is still on the barrel which which is connected to the gast tube which does cause inconsistent harmonics.

[TacCovert4]

The other thing is headspacing. A Bolt gun headspaces exactly the same every single shot. A semi-auto gun needs an extremely small, but present, amount of play in order for it to function reliably, especially as it gets dirty. A couple of thousandths of an inch change in headspace would affect both the pressure and the curve of the pressure build-up.

[Nichols]

Originally Posted by TacCovert4

The other thing is headspacing. A Bolt gun headspaces exactly the same every single shot. A semi-auto gun needs an extremely small, but present, amount of play in order for it to function reliably, especially as it gets dirty. A couple of thousandths of an inch change in headspace would affect both the pressure and the curve of the pressure build-up.

Good point.

[triggerjockey]

Isn't the action of a semi-auto already moving before the bullet leaves the barrel? If so, that would effect placement of the round wouldn't it?

[TacCovert4]

It's slight, but yes, the bolt has at least unlocked before the bullet leaves the barrel.

[triggerjockey]

Originally Posted by TacCovert4

It's slight, but yes, the bolt has at least unlocked before the bullet leaves the barrel.

Thinking about it, I would imagine that on the higher end semis that the action would be balanced to compensate for that though.

[johns624]

Originally Posted by triggerjockey

Thinking about it, I would imagine that on the higher end semis that the action would be balanced to compensate for that though.

Nothing to compensate for. Since it's the same every shot, sighting in compensates automatically for it.

[Nichols]

Originally Posted by TacCovert4

It's slight, but yes, the bolt has at least unlocked before the bullet leaves the barrel.

I don't know if there is an effect on the round....

Before I expand....I am only giving a SWAG.

I remember reading somewhere about the barrel life of semi-autos...something about 10,000 rounds only breaks down to like a half a second of barrel use....remember, I'm only giving a swag

The bolt on a semi wouldn't unlock until the gas pushes the bolt carrier back. The gas ports are usually towards the end of the barrel (except on carbines). I think the bullet is already out of the barrel before the bolt unlocks.

Barrel harmonics are still screwed up because of the gas block and possibly the gas venting back would offset....but I still think the bullet is out of the barrel before the gas effects the round placement......