Cartridge Efficiency vs Recoil

[dfanonymous]

I've been considering a 300WM recently and have been e.

I read that a 300 WSM (for example) can produce near identical muzzle velocities as a 300 WM with the same bullet

More scientific curiosity than anything. What has been your experience?

Mike

Depends what your definition of near identical. Also depends what range. to 800 yards, then whatever. Over 1000y....to say over a mile....you'll notice the difference. I'm starting think that people who cry about the recoil dont have a loaded bipod and the stock tucked firmly into their shoulder. I have a 95 lb girl who (whom?) my .300 beats the **** out of, but she still shoots it effectively if that makes sense.

 

[Danehunter]

If I didn't already have a .300 Win mag Browning A-Bolt and a Rem. 700-actioned HS Precision target rifle I'd get those rifles in .300 Norma mag. for its better ballistics for the about same recoil.

These days I compete with a Ruger Precision Rifle in 6.5 Creedmoor.
1. Lighter bullets by roughly 20 grains
2. Smaller powder charge than a .308 Win.
3. Flatter trajectory than a .308 Win. (Roughly the same as a 180 to 200 gr. bullet from a .300 Win mag.
4. Much better BC and sectional density than a .308 Win. thus less wind deflection.

So It ain't always the cartridge, per se, it's often the bullets available for that cartridge.For example my .300 Win mag shooting a 230 gr. Berger Hybrid bullet will have better ballistics than a 180 gr. Berger hybrid. But 10 years ago you could not find a 230 gr. bullet on .30 caliber. And 35 years ago you could not find a VLD bullet for .30 caliber. Again, it's availability.

Eric B.

 

[Carbine Kid]

G'day MikD31.
J D Custom gave you some useful figures. however it seemed to me that you were after a way to simply compare recoil figures.
Here is a simple formulae for "free recoil".

Fr = (Wp + Wb) x Wp divided by 80 x Wr.

Where : Fr = Free recoil in ft/lb
Wp = Weight of powder " grains
Wb = Weight of bullet " "
Wr = Weight of rifle " pounds

An example for a 308.

Fr = (46 + 150) x 46 divided by 80 x 8
= 196 x 46 " " 640
= 9016 " " "
= 14.09 ft/lb

AS you can see changing powder has a bigger effect than changing the bullet weight.
This is a simple comparator and doesn't account for energy variation between single and double base powders but to get quick comparisons that doesn't matter.
How does an individual "feel" recoil ? well that is up to him. However you can get accurate "free recoil" comparisons between different rifles and components.

Hope this helps.
Steve.

 

[FEENIX]

To bad the OP has not responded and if it provided him any insight.

Having said that, keep it simple and use recoil calculator/comparator below. gun)

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Rifle Recoil Table

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Cheers!

 

[MikeD31]

Holy crap. Sorry for the late reply guy's I haven't been on in a while. I appreciate all the feedback. JE your explanation is exactly what I was looking for. I didn't know about the bullet v. gas recoil but the way you explained it makes sense.

Thanks again.

 

[MajorSpittle]

G'day MikD31.
J D Custom gave you some useful figures. however it seemed to me that you were after a way to simply compare recoil figures.
Here is a simple formulae for "free recoil".

Fr = (Wp + Wb) x Wp divided by 80 x Wr.

Where : Fr = Free recoil in ft/lb
Wp = Weight of powder " grains
Wb = Weight of bullet " "
Wr = Weight of rifle " pounds

An example for a 308.

Fr = (46 + 150) x 46 divided by 80 x 8
= 196 x 46 " " 640
= 9016 " " "
= 14.09 ft/lb

AS you can see changing powder has a bigger effect than changing the bullet weight.
This is a simple comparator and doesn't account for energy variation between single and double base powders but to get quick comparisons that doesn't matter.
How does an individual "feel" recoil ? well that is up to him. However you can get accurate "free recoil" comparisons between different rifles and components.

Hope this helps.
Steve.

Of course changing the powder weight changes more then the bullet weight, because you are changing the bullet's velocity.

What I don't get with the formula is: Case capacity/Powder type isn't taken into account?

46 grains of some powder has the same energy as 60 grains of other powder depending on the cartridge it is used in. 46 grains of slow enough powder might only get 1500fps MV and 46 grains of another might get 3000fps MV with a 150gr bullet <--exaggerated expample for 308.

Being Energy is Mass X Velocity, in my example above the same weight powder, cartridge, bullet combination develops 2 times the energy depending on the type of powder.