Ammo question

Could be psychological but I always found 115gr to be snappy over 124gr. Anyone got scientific proof if lighter bullets are snappier than heavier ones or vice versa?
 
Usually lighter bullets produce less recoil, but there are a couple of things to consider. One consideration is the pressure level that the ammo is loaded to, for example a 115 gr +P load might produce recoil on par with a standard 124 gr load. The other consideration is that the difference between the two doesn't matter if you're using any sort of viable shooting technique. A firm grip, when combined with a solid stance minimizes muzzle flip; if you concentrate on your front sight and trigger control, you won't be disturbed by the recoil. I prefer the 147 gr loads myself, and the difference in weight between my S&W 469 and a Glock is only an ounce; 26 oz and 25 oz respectively.
 
Not an expert by any means, just going by some of what I've read about recoil.
Isn't a significant portion of the recoil from the expelling gasses from the barrel after the bullet has left?
I think that powder burn speed could contribute more to recoil than an extra nine grains on the projectile.

IIRC, expelling gasses is the common explanation for why a short-barrel gun recoils more than a long-barrel gun when shooting identically loaded cartridges. The projectile gets less energy but recoil is higher. This leaves the expelling gasses to blame for the increase in recoil.
 
Humm, did some researching and couldn't find a definite scientific answer. Even in a scientific forum, there was an argument about this!

The agreement was that a lighter projectile travels faster and would feel snappier but a heavier projectile would generate more rearward force and have more recoil. So in the end, the difference in "feel" between the two would be so slim as to not be easily distinguishable from each other.

As Boomer pointed out, proper grip, stance etc will help mitigate recoil.
 
relic38 said:
Not an expert by any means, just going by some of what I've read about recoil.
Isn't a significant portion of the recoil from the expelling gasses from the barrel after the bullet has left?
I think that powder burn speed could contribute more to recoil than an extra nine grains on the projectile.

IIRC, expelling gasses is the common explanation for why a short-barrel gun recoils more than a long-barrel gun when shooting identically loaded cartridges. The projectile gets less energy but recoil is higher. This leaves the expelling gasses to blame for the increase in recoil.
Click to expand...

Propellant gases only produce recoil when there is something to push against. Blank ammunition doesn't recoil upon firing, but when a projectile is introduced, recoil is directly proportional to the weight of that projectile. The powder charge has much less effect. Lets compare a 150 gr bullet in an 8 pound .30/06 rifle with both fast and slow burning powders, then with a 220 gr load with slow burning powder.

According to JBM, a 150 gr bullet that is loaded ahead of 49 grs IMR 4895 makes about 2800 fps and produces about 17 fp of recoil. When the same bullet is loaded with 59 grs of IMR 4831, its driven to a similar velocity, and produces 19 fp of recoil, a slight though measurable increase. But if we increase bullet weight to 220 grs, and 59 grs of R-22, while the bullet is driven to only about 2600 fps, the recoil jumps to 27 fp!

We see that there is quite a difference between the powder weight charge between fast and slow burning powders, yet the calculator suggests only a slight difference in recoil, but with an increase in bullet weight, the difference in recoil becomes quite significant.
 
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Boomer said:
Propellant gases only produce recoil when there is something to push against. Blank ammunition doesn't recoil upon firing, but when a projectile is introduced, recoil is directly proportional to the weight of that projectile. The powder charge has much less effect. Lets compare a 150 gr bullet in an 8 pound .30/06 rifle with both fast and slow burning powders, then with a 220 gr load with slow burning powder.

According to JBM, a 150 gr bullet that is loaded ahead of 49 grs IMR 4895 makes about 2800 fps and produces about 17 fp of recoil. When the same bullet is loaded with 59 grs of IMR 4831, its driven to a similar velocity, and produces 19 fp of recoil, a slight though measurable increase. But if we increase bullet weight to 220 grs, and 59 grs of R-22, while the bullet is driven to only about 2600 fps, the recoil jumps to 27 fp!

We see that there is quite a difference between the powder weight charge between fast and slow burning powders, yet the calculator suggests only a slight difference in recoil, but with an increase in bullet weight, the difference in recoil becomes quite significant.
Click to expand...

I have to disagree with the part in bold.
First, rockets propel themselves through space (a vacuum) by expelling gasses, works fine.
Second, the atmosphere is not nothing, so the expelled gasses have that as well to push against.

Blanks have a relatively small powder charge and do not build much pressure. The work being done is so small, any recoil is barely noticeable.

The basic physics are that any force in the muzzle direction will be felt by the gun and the holder in the opposite direction (as per Newton's Third Law of Motion). This includes forces from pushing the projectile, atmosphere, and even the expelled gasses in the forward direction.

I'm not saying expelled gasses is the only factor in recoil, but I do believe it can be a significant factor.
 
relic38 said:
I have to disagree with the part in bold.
First, rockets propel themselves through space (a vacuum) by expelling gasses, works fine.
Second, the atmosphere is not nothing, so the expelled gasses have that as well to push against.

Blanks have a relatively small powder charge and do not build much pressure. The work being done is so small, any recoil is barely noticeable.

The basic physics are that any force in the muzzle direction will be felt by the gun and the holder in the opposite direction (as per Newton's Third Law of Motion). This includes forces from pushing the projectile, atmosphere, and even the expelled gasses in the forward direction.

I'm not saying expelled gasses is the only factor in recoil, but I do believe it can be a significant factor.
Click to expand...

Your comparison to a rocket engine in space is interesting. When the rocket fires in space, it propels the space vehicle, the bullet if you will, but are the astronauts pushed back in their seats? If not, there is no recoil. If there is recoil from the combustion of the powder in a blank firing pistol, with no blank firing device attached, any recoil is far exceeded by the weight of the pistol, so there is no measurable, or should I say felt recoil without a projectile.
 
Boomer said:
Your comparison to a rocket engine in space is interesting. When the rocket fires in space, it propels the space vehicle, the bullet if you will, but are the astronauts pushed back in their seats? If not, there is no recoil. If there is recoil from the combustion of the powder in a blank firing pistol, with no blank firing device attached, any recoil is far exceeded by the weight of the pistol, so there is no measurable, or should I say felt recoil without a projectile.
Click to expand...

Yes, they would feel inertia when the rocket accelerates, regardless of the rocket being in space.

Regardless of what is being pushed (bullet, gasses, wad, etc) there will be an equal force in the opposite direction.
This applies even if the push occurs in a vacuum. Air resistance may add to it, but it's not required to have a force in the opposite direction of the push.

Now, since we are mainly talking about felt recoil, all these details about force are as important as the duration the force is being applied. As some mentioned, a heavy bullet may take longer to leave the gun, therefore that portion of the force (bullet acceleration) is not as 'snappy'. This might contribute less to felt recoil than a 'snappy' bullet.
 
From my experience, 115gr has the snappiest recoil, then goes 124gr, and 147gr has lightest recoil.

It fully corresponds to energy difference (info from Sellier & Bellot website):
100gr: 598 Joules http://www.sellier-bellot.cz/pistol-and-revolver-detail.php?ammunition=9&product=72
115gr: 570 Joules http://www.sellier-bellot.cz/pistol-and-revolver-detail.php?ammunition=9&product=67
124gr: 518 Joules http://www.sellier-bellot.cz/pistol-and-revolver-detail.php?ammunition=9&product=68
140gr: 419 Joules http://www.sellier-bellot.cz/pistol-and-revolver-detail.php?ammunition=9&product=73
150gr: 451 Joules http://www.sellier-bellot.cz/pistol-and-revolver-detail.php?ammunition=9&product=74

And it makes perfect sense because 9x19 is not 30-06, there is not much space for powder, and basically the smaller bullet you have, the more powder you can have.
 
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I don't know guys, wringing your hands over the recoil of a 9X19 cartridge when fired in a full sized pistol has me scratching my head. Shooting 325s in my .44 sometimes gets my attention. I've shot 115s, 124s and 147s in my little 469 Smith, and I can't say that bullet weight has effected my rate of fire or my score, but I'm not a competitive shooter, so my observations and experience might not be appropriate.
 
After the tens of thousands of 9mm I've shot over the years, I've found that 115gr is snappier and 147gr has a stronger push to the rear, 124gr is in the middle and is the perfect 9mm bullet weight IMHO. It depends on the ammo mfg and your gun too.

Some manufacturers I can't stand their #### no matter the weight, some make delightful pieces of art to shoot.
 
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