energy down range Semi-Auto vs Bolt

[vpsalin]

An old-timer told me that he thinks that a semi-auto has less down range power then a bolt action rifle. I'm thinking that in a real world hunting situation there would be no noticeable difference. Have people actually studied this...lol?

 

[Slamfire]

The action on my 35 Whelen Remington 7400 autoloader operates by drawing off some barrel pressure to cycle the action which results in a small loss in muzzle speed compared to a bolt action. Not much maybe 50 fps or less which shouldn't make a difference on game.

 

[350 Mag]

If you took same loading, same barrel length and fired in a bolt action vs semi it would be a little slower but not enough to make a difference on game animal.

 

[klaus enuff]

I believe it was military testing that revealed there is no practical difference between the two.

 

[9.3mauser]

The action on my 35 Whelen Remington 7400 autoloader operates by drawing off some barrel pressure to cycle the action which results in a small loss in muzzle speed compared to a bolt action. Not much maybe 50 fps or less which shouldn't make a difference on game

You could get more variation than that comparing two identical bolt rifles in the same calibre. The differences aren't worth worrying about, and the amount of gas bled off to run the action is negligible.

 

[brybenn]

Factory federal vital shock I think it was. Redish box with 180 gr nosler partition bullets in 300 wm are 70-80 fps slower in my savage 300wm than they are in my dad's 300wm. Same gun same specs. Both bolt action. Factory loads from the same box.
A semi maybe slower in most cases but nothing that would make a meaningful difference

 

[Slamfire]

The action on my 35 Whelen Remington 7400 autoloader operates by drawing off some barrel pressure to cycle the action which results in a small loss in muzzle speed compared to a bolt-action. Not much maybe 50 fps or less which shouldn't make a difference on game.

Also I recall reading that somewhere that semi-auto's produce less muzzle speed than a comparable bolt action. Sure enough, in Speer Reloading Manual No.12 in regard to the 7.62x39 load data..."We used a Ruger bolt action-action rifle in our tests; velocities in semi-automatic carbines will typically be 100 ft/s slower."

 

[Uisge]

Everything has a cost, operating the action takes a certain amount of energy, I’d imagine the type of action could play a role as well, but as had been stated nothing on the other end wil know the difference. Unless it’s a pack of coyotes, they might notice the follow up shots.

 

[tjhaile]

Also I recall reading that somewhere that semi-auto's produce less muzzle speed than a comparable bolt action. Sure enough, in Speer Reloading Manual No.12 in regard to the 7.62x39 load data..."We used a Ruger bolt action-action rifle in our tests; velocities in semi-automatic carbines will typically be 100 ft/s slower."

The Ruger bolt action also likely has a longer barrel than is typical for semiauto rifles in 7.62x39.

I would expect that the difference would be so trivial as to be less than the normal variation in individual barrels. Keep in mind that every barrel is wasting some energy in the form of muzzle blast.