Grain question

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Ok... newbie here..., again.

Got Carlotta..., my 92FS INOX... Gorgeous!!! Haven't yet taken her to the range, still practicing with the heft, carry and rack...

I see there is ammo from 115-? grain.

What is the difference between shooting a smaller over larger grain? Why select one over the other?

Thanks in advance...


Profiler :cool:
 
Lighter is usually faster, heavier usually penetrates more. These are generalizations and are dependent on a variety of factors. Someone will be along shortly to tell you I don't know what I'm talking about and give you a detailed compare and contrast.
 
The weight of the bullet is measured in grains. In 9mm 115, 124, and 147 are the most popular in FMJ's and there are other weights that you find more often in Hollow Points/Defensive rounds.

In general the lighter bullets shoot a little flatter and the heavier ones are better for knocking things like bowling pins over from a little more energy. Depending on the weight of the bullet and the velocity it travels at, they can effect the cycling of the guns action.
 
I like that Can effect cycloing of the action.....Some simple will not function period with 115 grain bullets and some will once they are broken in. Personally I like 115 grainers and even 105s but I load em hot.

The best thing for you to do is to look up your sepcific gun online and see if it has problems shooting specific weights and if it does buy and or reload accordingly.
 
Grains is a measure of weight, abbreviated gr, and they are most important in hollow point rounds.

As was said, in FMJ target/practice ammo... 115, 124, and 147 grain are what you will find. 115gr is the most common and readily available, 124gr is next common and I don't find it in stores readily, 147gr is the least common I find.

How the pistol shoots in relation to point of aim vs point of impact, and recoil characteristics, will be different between the bullet weights. The difference in impact will not really be anything to think about unless you are shooting 15 yards or more. In that case, the heavier round will tend to shoot lower than the lighter round.

Heavier rounds tend to spread out recoil over a slightly longer period, which some like... it has higher overall recoil, but feels slower like a hard push rather than a quick punch. Not the best analogy, but should help visualize the differences a little.

In defensive hollow point ammo, there are a few other weights as well, due to the differences in bullet design. Some are lighter than 115gr, and some are various weights up to 147gr. I won't list them all.

There are some general guidelines that will help here...

Stick to 124gr or heavier for defense use. Lighter bullets tend to be less consistent in how well they perform in ballistics testing. They tend to not penetrate consistently, sometimes not penetrating to the accepted minimum distance. The Barnes all copper 115gr hollow point does buck this trend and works well.

Lighter than 115gr tend to be frangible rounds, and their effectiveness is in debate. They almost all tend to under penetrated in tests, and any that do meet minimums tend to do so with only a small portion of their mass.

Winchester has released their "train and defend" line of bullets. The train is a 147gr fmj, that is shaped the same, weighs the same, and is said to be ballistically the same as the defend loading. The Defend loading looks to be their PDX1 bullet, a very good bullet for defense. The point of all this is to make it easier for new gun owners, but the training FMJ is more expensive than other brands. The benefits are that the rounds will hit the same place relative to point of aim, recoil the same as the hollow points, and the similar shape helps ensure that the hollow point will feed reliably, as if the fmj does, most likely the hollow point will as well.

Reliable feeding is important... all modern pistols should function reliably with FMJ, but sometimes a pistol may not like certain types of hollow points, even identical models can be different. Usually, a pistol will function well with all types, but occasionally you get one that has preferences. you may find your 92fs doesn't like Hornady critical defense, but your neighbor's 92fs may love them... This is why you should always fire some of your chosen hollow points through your pistol to ensure there are no reliability issues. How much is a personal choice. Some feel a couple boxes is enough, others several hundred is a minimum.


When looking at defensive ammo, another point to consider is pressure. There is standard pressure, +P, and +P+... This is usually related to how much gunpowder is used in the round, and more pressure typically means higher velocity and recoil. FMJ target ammo tends to not offer +P or higher.

Standard pressure is the original pressure spec that SAAMI listed. +P is a SAAMI recognised increased power spec, and +P+ is an unrecognised pressure spec above +P. SAAMI is an industry formed regulatory body for arms and ammunition manufacturers... to ensure everyone is on the same page for specs.

I try to use standard pressure loads when possible, but some prefer to use +P for their defense ammo. I avoid +P+ due to it being not an industry standard. I find standard pressure rounds in a well designed hollow point tend to perform just as well as +P.

My personal choice is Federal HST 124gr, but there are several good loads out there from other manufacturers. Others may pop in and mention them.


Hope that wasn't too much info for a crash course in bullet weight and design.
 
Grains are an avoirdupois unit of measure of weigh(actually mass). 7,000 to a pound. 437.5 to an ounce. Think physics.
The potential energy of light stuff isn't as high as that of heavy stuff. You do get to a point of diminishing returns and limits to a loaded cartridge's length while still being able to fit it into a magazine and chamber.
Heavy stuff has more recoil, both felt and actual(felt recoil can be 'tamed'. Actual recoil is physics.), than lighter stuff. Even though the light stuff tends to be going faster. The equal and opposite reactions that Newton guy was always going on about.
 
Nothing much to add except that I prefer 124 gr in 9mm. I shoot a lot of 115 gr ammo for informal target practice and plinking because it is cheaper. But for serious work 124 gr has the best balance of qualities I'm looking for.

There are those who prefer lighter, or heavier. I think they have their place, but more for special purposes. To me 124 is the best all around.
 
marine6680 said:
...How the pistol shoots in relation to point of aim vs point of impact, and recoil characteristics, will be different between the bullet weights. The difference in impact will not really be anything to think about unless you are shooting 15 yards or more. In that case, the heavier round will tend to shoot lower than the lighter round.
Click to expand...

I'm agreeing -- but offering an explanation/rationale. I think I'm right in these comments, but welcome correction if I'm not...

Part of it is about bullet speed and gravity, and a very small part of it is about recoil. This explanation, however, assumes a comparison with some variables held constant: barrel length, bore axis, barrel design, point of aim. You can't do that with all semi-auto pistols (i.e., compare easily).

Because gravity doesn't care about bullet weight -- a 115 gr. bullet drops at the same rate as a 147 gr. bullet -- but because the lighter bullet is going faster it will go farther in the same amount of time as a heavier bullet. For a given target distance (which the lighter bullet reaches sooner), the lighter bullet will have dropped a bit less and have hit the target a bit higher than the heavier bullet.

While most semi-autos seem to have barrel flip when fired, some seem to have more barrel rise than others -- and that can affect what happens with targets that are closer.

In those guns, a heavier bullet might show a higher point of impact at closer distances than a lighter bullet. That's because that heavier bullet going down the barrel at a slower pace allows the barrel to raise just a bit more before the bullet exits the barrel. That slightly higher barrel angel will change the point of impact on closer targets.

Not all guns are the same and not all guns handle recoil in the same way. Ported guns will handle recoil much differently, for example.

In most of my 9mm guns, I've not seen much difference in points of impact between 115 gr. vs 124 gr 9mm rounds, but have seem slightly higher points of impact with 147 gr. rounds at 10-15 yards. Your results may vary, depending on the gun design, etc.
 
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I'm going MAYBE here with regards to bullet drop. It is pretty well proven that heavier bullets impact HIGHER than lighter bullets at moderate range from handguns, and sometimes from rifles.

The reason is that the greater recoil from heavier bullets results in more muzzle rise before the bullet exits the bore. It doesn't take more than a few 1/1000's" of difference in the muzzle rise to make a bullet hit 1-2" higher at 15-20 yards.

This is a fairly common observation when shooting magnum revolver rounds when hunting. Now when you start talking about longer handgun ranges of 50 yards of more then the heavier bullets do start dropping somewhat faster.
 
All good points, but if you are buying factory loads for casual shooting or club level competition, you will find that copper and lead are expensive, so lighter bullet ammo is cheaper. And it will serve about as well. When I was between shops, I shot a lot of what I call "econoball", 115 grain Winchester White Box from Walmart mostly. While I prefer my own handloads with heavier bullets, I can't say there is a LOT of difference.
 
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