Recoil Question

SlimWallet

Guys,
Can you help me?
Assuming two projectiles have the same energy at the muzzle in foot-lbs, do they have the same recoil? Assuming the guns are equal weight. Equal and opposite reaction, etc.

SlimWallet

I have notieded the recoil from it is different when using steel or lead. While using full choke

Steel= More Recoil
3in
Dram Eq. MAG
1 1/4 oz. of shot
BB shot
Velocity 1300 FPS


Lead=Less recoil
2 3/4in
Dram Eq. 3.5
1 1/4 oz of shot
6 shot
Velocity 1300 FPS

I just wonder why the steel has more recoil? Any input
Thankyou

SlimWallet

Gents,

If you have two brass in 30.06 and put the same amount of powder in both cases but load one with a 150 grain bullet and the other with a 200 grain bullet, will the recoil be the same because the powder charge is the same or will the shell with the 200 grain bullet kick more as it is more weight being moved out the barrel?

Thanks,

Slim

PA Shootist

All other things being equal, and they seldom are, yes, the heavier bullet will have more recoil. But it's not exactly that simple. With the same powder charge, the heavier-bulleted cartridge will likely have a much higher chamber pressure. And bullet bearing surface and shape, and bullet and/or jacket hardness can affect the pressure and thus the recoil, up and down. As well as seating depth. And so forth... You get the picture! But in general, the answer would be yes.

iwannausername

If you accelerated them to the same velocity, the heavier bullet would recoil more. Which is I think the question you may have been asking... but the above re:pressures, etc. is also 100%

sig232

In my opinion that is why it is important to use the manuals produced by the various powder companies and others. I have many in order to take advantage of the years of research done by many folks and have at hand lots of choices for reloading.

Check your manual before using a set amount of powder and changing from a 150 gr to a 200 gr. Pressure can change very quickly with different bullet weights and improper seating of those bullets.

Don't take chances by expermenting unless you are a pro. You could blow up a gun or release pressure in a way that can cause injury.
Be safe and use the massive amounts of data available. There is a wealth of 30-06 information available to you from many sources.[:0][:0]

heavyiron

Hi,

Good question.

Here is the answer based strictly on a Newtonian physics (external ballistics) type of answer.

Recoil, as it appears in ballistics and recoil tables, is calculated according to the following equation:

Re = Wg*(A*(Wb*Vb+Wc*Vg)/CF/Wg)^2/Ag

Where:

Re = Recoil energy, ft/lbs
Wg = Weight of gun, lbs
A = 32.2 Acceleration of gravity, fp/s/s
Wb = Weight of bullet, grains
Vb = Velocity of bullet, fps
Wc = Weight of powder charge, grains
Vg = 4000 Velocity of powder gases, fps
CF = 225400, Unitless
Ag = 64.4 Acceleration of gravity doubled, fp/s/s

As will be noted there are no other variables that enter into the calculation of recoil energy. Other factors such as recoil pad, brake, chamber pressure, bullet friction, etc. are attributes of "felt" recoil but are not quantified. There is no such calculation that I am aware of to account for "felt" recoil factors although they do exist.

I tried to calculate this on an even playing field and keeping the numbers true to your question. A max load for the 30-06 with a 200 grain bullet requires about 55.5 grains of powder to be used. In comparison, 55.5 grains of powder for a 150 grain bullet is not a maximum load, but your question was "both loaded with the same amount of powder". Velocity for the 200 grain load was set at 2651 fps and the 150 grain load at 2750. Velocity and powder charges are from the Nosler Reloading Manual. The rifle weight was set at 7 pounds.

The recoil energy was 18.23 ft/lbs for the 150 grain bullet and 25.62 ft/lbs for the 200 grain bullet. Therefore, the 200 grain bullet has more recoil. This difference is enough to be felt.

A second run was to compare the maximum load for a 150 grain bullet to the maximum load for the 200 grain bullet in the example above.

The 150 grain bullet with 60 grains of powder at a velocity of 3075 fps resulted in recoil energy of 22.26 ft/lbs compared to the recoil energy of 25.62 for the 200 grain bullet maximum load. Therefore, even at maximum loads the 200 grain bullet will still have the most recoil.

But that isn't the whole story. The 30-06 loaded with a 180 grain bullet, velocity of 2985 fps, and 62 grains of powder produces more recoil than any of the above examples, generating almost 28 ft/lb of recoil. Why? Even though the 180 grain bullet has a smaller mass than the 200 grain bullet, it generates more recoil because the velocity is still relatively high. The 180 grain load will also generate almost 450 ft/lbs more muzzle energy than the 200 grain load! Think of that the next time before a hunting trip.

The above numbers can be tweaked a bit but the recoil energy is most effected by the velocity and the bullet weight since these are both the largest variables in the formula and both are squared. In the equation the weight of powder also has to taken into account since it also is being ejected from the barrel, just like the projectile.

One of the more effective means to reduce recoil is to increase the weight of the rifle.

Hope this helps answer your question.

Regards,

Heavyiron

SlimWallet

Gents,

Thanks so much for your very thorough and enlightening replies. I reloaded quite a bit a number of years ago and may get back into it.

Looks like I'd bette study up a bit!

Thanks again!

Slim

easygo6

heavy...be fair and give the man a complete answer!!!

Know anything about how the Panthenon relates to the growth in plant cells???[:)]