Thread: Calculating recoil from muzzle energy and rifle weight?

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.

Originally Posted by MB

Yes, it also might mean that I don't need to buy another rifle! 732 ft.lb energy at 200 yards (Hornady data). Not the 1000 ft.lb that our American friends consider necessary for a clean kill and I wouldn't go chasing big reds or sambar with it, but for most other things...

Hah ignore that mate and keep in mind what sub 22lr and put the bullet where it will break something important and things will go down fine

My 10-22 still kills more than anything else in my gun cabinet but 300blk is just easier



Subx done the business this week


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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.

There is a formula in one of my old Lyman reloading manuals which works well. You may be able to find it online. If not, let me know and I can probably find and photograph it @MB