Home Forums Hunting & Shooting Ask The Gunwriters Recoil question

Could a guy create a load that recoils less because of a smaller powder charge, but still has similar velocitys? Meaning.... How much effect does the size of the powder charge have on recoil? Using everything the same; gun,bullet,brass, and primers.
Some max loads end up with as much as 10 grs spread from powder to powder in the same cartridge. Do these recoil differently? Any truth to this, or does pressure dictate recoil?

The recoil formula takes powder weight into account, so it has an effect, but I haven't felt it. In fact, some loads with faster powders and smaller charges seem to have more recoil force for me than heavier, slower charges. Recoil velocity may have something to do with that, but I am not sure that changes much either with same bullet at same velocity. There are other factors that make so much more difference than powder charge: stock length and fit, layers of clothing, presence of recoil pad, gun weight, etc.

IME, if you want to reduce recoil enough to notice it, switching to a faster burning powder won't do it. Dropping bullet weight and velocity, or REALLY dropping bullet weight make a noticeable difference. That is why reduced recoil factory ammo uses light bullets at moderate velocity.

Even though the weight of the powder makes a difference, it's not enough to notice

You can use a good ballistics calculator to figure the change, but it will be very small fractions of a pound

Yes, you're right about the powder choice, but the difference is quite small.

An example using max loads from the Nosler Load Data site, using a 7.5lb 30-06 with 150gr bullets:
61.5gr of RL19 produces 2982fps @ 22.8ft/lbs of recoil
53.0gr of IMR4320 produces 2940fps @ 20.1ft/lbs of recoil

What I've found is that a quality recoil pad and proper stock dimensions make far more difference.

On the other hand, using a non-max load to decrease velocity might be something you want to explore. For example:
49.0gr of IMR4320 produces 2760fps @ 17.6ft/lbs

THAT makes a difference to my shoulder.

Oh yes it does.

I can get identical speeds from my 300 WSM as a 300 WM, but with 12-15 gr less powder. Yea,I know the WM can be loaded about 50-75 fps faster, but both CAN be loaded to the same speed.

The weight of the powder charge must be added to the bullet weight. Normally when you increase bullet weight by 15 gr, the powder charge is decreased as is bullet speed and you still see more recoil.

The net effect on recoil in the 300 WSM vs 300 WM example above is like comparing a 180 gr bullet fired at the same speed as a 165 gr bullet. Trust me, you will notice.

I don't notice, regardless of whether you're trustworthy. I know what the formulas say, and I don't want to argue numbers, but significantly recoiling guns, I've not noticed much difference between bullet weights as much as 25% apart. I've found faster burning powers produce 'sharper' recoil when loaded at max when compared to slowest powders near max. Maybe I'm a freak, but I don't find a positive correlation, or feel a quantifiable difference based on a some small percent difference in total charge weight. Sticking with same cartridge comparisons may be a better apples-to apples-comparison.

Yep, same case for comparison or it doesn't matter. That said; the 300 wsm is ALL THAT... IMO.

There is a difference in perceived recoil between total recoil energy and recoil velocity, but generally less powder equals less recoil.

If you shoot rounds that generate significant recoil, you can definately tell that some powders recoil more than other, even with bullets traveling at the same velocity.

The two times I've been able to notice the difference were with MY 350 Rigby, ~66gr of Varget or 72 gr of H-4350 would drive a 250 gr 2700 fps. The 4350 load was a harder kicker.

The other case was the 458 lott, using RL15 and VV N550, both with 450 gr X. The N550 load was a harder kicker, and 100 fps slower than RL15.

With powder, you need to remember that the burning gas is leaving the barrel at a higher velocity than the bullet, so that extra 5-10 gr is traveling at ~5000 fps and you can feel that as added recoil.

There are four things that effect recoil.

1. Weight of the rifle
2. Weight of the projectile
3. Weight of the powder charge
4. Velocity of the projectile

This has to do with the actual foot pounds of recoil energy and not the "felt recoil" which is dependent on stock design and rifle fit.

When looking for a load for my wife in a 30-06, adding weight to the rifle was not an option. An 8 pound rifle (all in) was as much as she wanted to carry. Primarily to be used for moose. I loaded Barnes TSX 150 grainers in lieu of the 165 or 180 grainers that I used, and I gave her a charge of 47 grains of H4895 for a MV of about 2800-2840 fps.

It was significantly less recoil than a 180 grain bullet loaded with 58 grains of H4831 and a velocity of 2750 in the same rifle. And she killed a nice young bull with it. Bonus. It died on the spot.

You could buy one of those PAST recoil pads that you wear on your shoulder. They significantly reduce the recoil you feel. I use one when sighting in my hunting rifles or testing handloads.

Felt recoil is the only thing that matters, as that is what you have to deal with, not numbers on a calculator or spreadsheet.

I can assure you that with guns that produce recoil of 40 ft pounds and up, going to a slower burning powder that the recoil from that powder that leaves the muzzle at a higher pressure due to it's slower burn rate makes for an increase in felt recoil, sometimes quite significantly.

I'm with Lott. The muzzle gas pressure also effects recoil, if the powder is slower, you get more bang. Bet that 4350 load in that 35 is louder than the Varget.
As for recoil overall, if it's such an issue for you, downsize. No shame in it. I hate guns that hurt both ways.

From what I've read it's not so much the pressure at the muzzle as it is the velocity of the powder gasses exiting the muzzle; in a way they're related but it's not pressure per se.
I believe that most recoil formulas assume somewhere on the order of 4000-4500 fps velocity of the powder gasses to calculate the "rocket effect". When you consider that energy (of powder gasses, recoil or bullets, etc.) increases with the square of the velocity, one can see that an extra 10-15 grains of powder can have a pretty significant effect on total recoil.
Muzzle brakes take advantage of the "rocket effect" by directing some of those high velocity gasses slightly to the rear.

The equal and opposite reaction which produces recoil is a momentum, not energy, balance. Momentum is linear in velocity.

You must consider that the mass of the gas is around 1/3
that of the bullet. Also on the average the gas velocity is
1/2 that of the bullet.
Recoil has nothing to do with energy. it is an impulse.

A firearm in recoil has both momentum and energy. Two different formulas, right?Momentum = mass times velocity as you said. Energy = mass times velocity SQUARED and the energy of the firearm is equal to the energy of the ejecta (both the bullet and powder). Double the velocity and you quadruple the energy of a bullet, firearm, etc.

Fortunately for us, because the mass of the firearm FAR exceeds that of the ejecta, the recoil velocity of the firearm is a whole lot less than that of the bullet/powder gasses.

Yes there are energy and momentum, but the recoil energy of the firearm is definitely not equal to the energy of the ejecta.

Part of felt recoil is the duration or speed of the recoil impulse. For an extreme example consider the Remington 1100 is designed to produce three relatively slow recoil impulses, the greatest around 50% of the total. Feels much, much softer than a single shot though the recoil is the same. No idea if there's a meaningful difference with a bolt gun with fast/slow powders.


Now that I've muddied the waters even more, my real answer is the OP has a good excuse to build some different loads and see how they feel. More fun than trying to guess how it will work out with so many hard to quantify variables.

It's not "rectal extraction"; it's Newton's third law...for every action there is an equal and opposite reaction. Conservation of energy..