Semiauto For Long Range

T.A.Sharps · June 3, 2008, 06:20 PM

I've always heard about semiuto actions being less accurate at long range.

No one has ever told me what a bullet from a semi auto action would do at longer range that a bullet from a bolt action wouldn't.

I understand about there are more moving parts in a semiautos, but I have seen highly accurate AR-15's and M1A1's cabable of sub MOA.

Anyone know, technically, what can happen to have it considered less accurate?

HighPrimer · June 3, 2008, 07:51 PM

There are many reasons why a semi-auto 'might' be less accurate than a bolt or single shot. Much has to do with the bedding of the action into the stock, and with the moving parts of the action (if they start to move before the bullet exits the muzzle, accuracy could be affected). Firearm accuracy is all about doing the exact same thing every time the trigger is pulled. More moving parts means more chance for something different to happen.

The above concerns general accuracy. Long range accuracy depends largely on what effects short range general accuracy. If a bullet exits the muzzle of a semi-auto rifle at the same speed, rotation and dispersion as the same bullet from a bolt action, there will be no difference in long range accuracy. The comment about long range accuracy really means less short range accuracy too.

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Zak Smith · June 3, 2008, 08:28 PM

Generally, a semi-auto will be much more expensive than a bolt gun that gives the same accuracy. Also, bolt guns can generally shoot a wider variety of loads and/or get more velocity.

4EVERM-14 · June 4, 2008, 03:33 PM

Vibrations and harmonics.
Semi's, having more moving parts, are subject to associated parts vibrating independantly. Unless these create a constant harmonic balance consistantly accuracy may not be reliable. Bolt guns are less susceptible to this. Properly bedded the barrel is the the only vibration concern.

T. O'Heir · June 8, 2008, 02:57 AM

"...No one has ever told me what a bullet from a semi-auto action would do at longer range that a bullet from a bolt action wouldn't..." Usually the other way around, but a bullet is a bullet. Hitting the target is what matters. Semi-autos are inherently less accurate due to all the moving parts 4EVERM-14 mentions. However, a semi-auto can be built to shoot almost as well as any bolt action.
"...what can happen to have it considered less accurate?..." A stock barrel, a stock trigger, stock sights and mediocre ammo. Ammo being the most important thing. A great bolt action won't shoot well with mediocre ammo.
"...have seen highly accurate AR-15's and M1A1's cabable of sub MOA..." Yep. None of which are stock rifles. Mind you, a lot depends on what you consider to be long range. "Stock", generally, meaning a standard factory rifle.

UniversalFrost · June 8, 2008, 12:03 PM

for repeatability it is where the bolt action rules.

my 10-t, sr-25 and bushy vaminter all enjoy sub moa at 100 yards and the 10-t and sr-25 enjoy sub moa at 200, then the groups start to open up

June 3, 2008, 06:20 PM	#1
T.A.Sharps Senior Member Join Date: December 28, 2007 Posts: 675	Semiauto For Long Range I've always heard about semiuto actions being less accurate at long range. No one has ever told me what a bullet from a semi auto action would do at longer range that a bullet from a bolt action wouldn't. I understand about there are more moving parts in a semiautos, but I have seen highly accurate AR-15's and M1A1's cabable of sub MOA. Anyone know, technically, what can happen to have it considered less accurate? __________________ " ...Said I never had much use for one. Never said I didn't know how to use it..." "Your reality, sir, is lies and bladerdash, and I am delighted to say I have no grasp of it whatsoever!"

June 3, 2008, 08:28 PM	#3
Zak Smith Senior Member Join Date: December 12, 1999 Location: Fort Collins, Colorado, USA Posts: 2,682	Generally, a semi-auto will be much more expensive than a bolt gun that gives the same accuracy. Also, bolt guns can generally shoot a wider variety of loads and/or get more velocity. __________________ Zak Smith . DEMIGOD LLC . THUNDER BEAST ARMS CORP . COLORADO MULTI-GUN *My PM inbox full? Send e-mail instead.*

June 4, 2008, 03:33 PM	#4
4EVERM-14 Senior Member Join Date: November 12, 2006 Location: Pennsy Posts: 720	Vibrations and harmonics. Semi's, having more moving parts, are subject to associated parts vibrating independantly. Unless these create a constant harmonic balance consistantly accuracy may not be reliable. Bolt guns are less susceptible to this. Properly bedded the barrel is the the only vibration concern. __________________ David NRA Benefactor Member Distinguished Rifleman #731 Presidents 100

June 8, 2008, 02:57 AM	#5
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	"...No one has ever told me what a bullet from a semi-auto action would do at longer range that a bullet from a bolt action wouldn't..." Usually the other way around, but a bullet is a bullet. Hitting the target is what matters. Semi-autos are inherently less accurate due to all the moving parts 4EVERM-14 mentions. However, a semi-auto can be built to shoot almost as well as any bolt action. "...what can happen to have it considered less accurate?..." A stock barrel, a stock trigger, stock sights and mediocre ammo. Ammo being the most important thing. A great bolt action won't shoot well with mediocre ammo. "...have seen highly accurate AR-15's and M1A1's cabable of sub MOA..." Yep. None of which are stock rifles. Mind you, a lot depends on what you consider to be long range. "Stock", generally, meaning a standard factory rifle. __________________ Spelling and grammar count!

June 8, 2008, 12:03 PM	#6
UniversalFrost Senior Member Join Date: February 20, 2006 Location: Ohio Posts: 2,300	for repeatability it is where the bolt action rules. my 10-t, sr-25 and bushy vaminter all enjoy sub moa at 100 yards and the 10-t and sr-25 enjoy sub moa at 200, then the groups start to open up __________________ Lifetime member VFW and NRA "Quando Omni Flunkus Moritati" (when all else fails play dead) -Red Green

June 3, 2008, 07:51 PM	#2
HighPrimer Junior Member Join Date: January 6, 2006 Location: Valley of the Sun Posts: 10	There are many reasons why a semi-auto 'might' be less accurate than a bolt or single shot. Much has to do with the bedding of the action into the stock, and with the moving parts of the action (if they start to move before the bullet exits the muzzle, accuracy could be affected). Firearm accuracy is all about doing the exact same thing every time the trigger is pulled. More moving parts means more chance for something different to happen. The above concerns general accuracy. Long range accuracy depends largely on what effects short range general accuracy. If a bullet exits the muzzle of a semi-auto rifle at the same speed, rotation and dispersion as the same bullet from a bolt action, there will be no difference in long range accuracy. The comment about long range accuracy really means less short range accuracy too. .