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Are semi autos less powerful than a bolt action?

7867 Views 28 Replies 14 Participants Last post by  squirrelsniper
Im sorry i keep asking so many questions about this rifle!I heard that semi autos are less powerful than a bolt action.Is this true?
Browning BAR 7mm Rem Mag.

Edit:Sorry i didnt know.i wont do it again!
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While it's true that some of the propelling gases are siphoned off to operate the action, the gas volume used is relatively insignificant. Furthermore, by the time the gas system unlocks the bolt and allows it to begin rearward travel, the bullet is out the barrel and pressures have dropped to a safe level. Thus, all else being equal, the difference in velocity between a gas operated semi-auto (really a bolt action operated by gas forces) and a bolt action is negligible.
I have however shot a lot of rim-fire 22lr. I have a 10/22 and a cz 452 varmint. The barrels on these guns are very close to the same length and I shoot the same ammunition in them. With both guns zeroed at 75 yards the 10/22 drops 8-10 inches more at 200 yards than my bolt action CZ.
This is my thoughts on this and it could be wrong, but the energy that moves the action back and forth has to come from someplace. Now if that energy was just the energy that was otherwise just going to give you more kick then it shouldn't make any difference but if some of that energy was going to be used to propel a projectile then it could make a difference.
With a blowback operated rimfire, where the bolt starts moving aft almost as soon as the bullet launches, you may indeed be losing some energy to operating the bolt. In a gas operated centerfire, there's enough of a delay before the bolt is unlocked and startes traveling rearward that I doubt the difference is noticable. I should pull out my chronograph and check some of my .22's. It would be interesting also to chrono a centerfire semi-auto with the gas system disabled (in effect, a straight-pull bolt action) against the same gun operating normally to see what the effects were.
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