Thread: Calculating recoil from muzzle energy and rifle weight?

Should be possible shouldn't it? Cant find an online calculator or formula. Any thoughts?

Conservation of momentum. Momentum of projectile leaving barrel = momentum of rifle recoiling. Momentum = mass(kg) x velocity (m/s)

Here is a recoil calculator

https://shooterscalculator.com/recoil-calculator.php

Originally Posted by stug

Here is a recoil calculator

https://shooterscalculator.com/recoil-calculator.php

That calculator works well enough to compare recoil of different loads.

Here's a comparison i did with my M7 6.5CM with full power 140gr eldm loads compared to my 123gr reduced recoil youth loads for my 8 year old.

Damn stupid forum wont let me add the 2nd image.

But the 123 gr numbers are:

123gr
2600 fps
30gr Powder
8 Lbs rifle weight

Recoil impulse 2.09 lbs.sec
Recoil Vel 8.39 fps
Recoil Energy 8.75 ft.lbs


A big reduction in felt recoil

Originally Posted by GWH

That calculator works well enough to compare recoil of different loads.

Here's a comparison i did with my M7 6.5CM with full power 140gr eldm loads compared to my 123gr reduced recoil youth loads for my 8 year old.

Damn stupid forum wont let me add the 2nd image.

But the 123 gr numbers are:

123gr
2600 fps
30gr Powder
8 Lbs rifle weight

Recoil impulse 2.09 lbs.sec
Recoil Vel 8.39 fps
Recoil Energy 8.75 ft.lbs


A big reduction in felt recoil

For those interested in the difference in the terminal performance of the two loads:

140gr eldm at 2850 fps holds 1,000 ft lbs and 1800 fps to 720 yards

123gr eldm at 2600 fps holds 1000 ft lbs and 1912 fps to 420 yards, still well enough for most hunting situations for most people and well enough for most shots inside 300 yards that my 8 year old would be taking.


Out of interest if i was to use a 100gr Nosler ballistic tip in place of the 123 gr eldm for the light youth load, to get the same level of energy at 420 yards, as i get with the 123 gr, id have to push the 100gr at around 3250 fps.

So when looking at doing this stuff and trying to maximise effective distance (even when using a lower velocity youth load), it really helps to use a bullet that still has a reasonable BC.

https://www.omnicalculator.com/physics/recoil-energy

For all of those calculations, I need information on powder charge which I don't have (factory rounds).

You are still going to need powder weight because that is also being “thrown” down the barrel. Muzzle energy will only be energy of the projectile and won’t take into account the energy of the powder.

Originally Posted by stug

You are still going to need powder weight because that is also being “thrown” down the barrel. Muzzle energy will only be energy of the projectile and won’t take into account the energy of the powder.

And bear in mind the insane velocity of the gases as they exit the barrel.

In the big scheme of things I gotta ask......why ? What does it matter ? Genuine question no hate

Originally Posted by dannyb

In the big scheme of things I gotta ask......why ? What does it matter ? Genuine question no hate

Centrefire ammunition that my young son can use.

Originally Posted by MB

Centrefire ammunition that my young son can use.

Do you have a pre determined energy level as a cut off ? Otherwise just go light for caliber and limit range, I was shooting 125gn accubonds in my 308win and it was very light recoil but still a solid performer

Originally Posted by dannyb

Do you have a pre determined energy level as a cut off ? Otherwise just go light for caliber and limit range, I was shooting 125gn accubonds in my 308win and it was very light recoil but still a solid performer

Just weighing up options. I was interested to see that "lite" .308 rounds have less muzzle energy than standard .243 ammunition. Wondered how that translated to recoil.

Originally Posted by MB

Just weighing up options. I was interested to see that "lite" .308 rounds have less muzzle energy than standard .243 ammunition. Wondered how that translated to recoil.

300blk 135 supersonic have very little recoil
Make sure the speed the bullets are going once slowed down are still within their projectile performance range so they still expand

165 ballistic tips won’t expand even with bone contact at 1000fps



The subs don’t seem to do much even with a close range heart shot surprisingly but pigs are gonna pig and just keep running


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Just estimate the weight of the powder, you wont be far off . ...