Howard

165 gr versus 180gr - what's the difference besides 15?

12 posts in this topic

As a new shooter I am still trying to learn lots of stuff. One of the things I have yet to figure out is what is the difference between a .40 cal round that is 165 grain versus 180 grain -- please don't tell me 15 grains ;)

 

What I am asking is what is the difference between how it travels, what it does on impact, and the recoil in the gun. Do they have the same amount of powder in the shell? Do travel at different speeds, or have different amounts of energy at impact? What is the reason for having two different common sizes? Which one am I better off using for target shooting, what about as a defensive round. Let's keep it simple and not bring JHP type rounds into the equation for now.

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Apples to apples a 165 should travel faster than a 180.

 

The chamber pressure is balanced by changing powder charge when you change bullet weight. Heavy bullets necessitate a lighter powder charge, and a lighter bullet can be pushed a little faster with more powder.

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My 10MM 165gr TMJ's have a velocity of 1400 fps, energy of 718 ft lbs, and TKOF of 13.20 while the 180gr TMJ's (15gr higher) run at 1300 fps, 676 ft lbs and a TKOF of 13.37. These are both from the same manufacturer. You might have a disparity in the data when you compare among different manufacturers. These two are also running supersonic out of the muzzle as compared to .45 ACP which has many sub-sonic cartridges available. It would be interesting to compare the ballistic gel penetration depths.

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The .40 S&W cartridge is an offshoot in the development of the 10 mm. IIRC, this was done at the behest of the FBI, who were going to adopt the 10 mm as their new duty round, but found that the guns chambered for it had large grips that were difficult for shooters of small stature to handle. That and the fact that the recoil was pretty stout, which made for difficult shot-to-shot recovery. They first attempted a lighter loading of the standard 10 mm round, but malfunctions increased.

 

So they took the 10 mm and shortened it by 3 mm, and named it the .40 S&W (and no, it does not stand for Short & Wimpy). The common bullet in the 10 mm was 180 grains and that just carried over to the .40. 180 was the standard loading for quite a while, and a lot of .40 S&W firearms produced today still have their sights regulated at the factory with 180 gr ammo.

 

Just as with any caliber, the longer it exists the more experimentation with it there is and the more bullet weights for a given caliber are developed. Having a variety always gives the shooter the choice between light bullets at higher velocities, or large bullets at lower velocities - and the argument over which is better is akin to a Chevy vs. Ford argument.

 

Adios,

 

Pizza Bob

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Adios,

Pizza Bob

 

So Bob, to answer the OP question, what is the difference in two .40 cartridges with a 15gr difference? I don't shoot .40 so I tried to give comparative data for two 10MM rounds with a 15gr difference from the same manufacturer. Neither do I have any data on .45ACP in my ammo log from the same manufacturer with a 15gr difference to provide.

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From Federal's website...

 

 

AE40N1

Target.png 40 S&W 180 1000 TMJ American Eagle® IRT

AE40R1

Target.png 40 S&W 180 1000 Full Metal Jacket American Eagle®

AE40R2

Target.png 40 S&W 155 1160 Full Metal Jacket American Eagle®

AE40R3

Target.png 40 S&W 165 1130 Full Metal Jacket American

Eagle®

 

It would appear that it is 30 FPS per bullet weight increment, in this example.

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There's a pretty good difference between 115 and 124gr 9mm's, not to say every cartridge will behave the same, but generally lighter bullets can get more force behind them keeping the pressure and power factor relatively the same while increasing velocity, becoming more snappy. depending on your barrel and twist one might be more accurate then the other. Where in the .223 55 vs 65gr similar accuracy can be the difference between a different twist rate. A lot of things can change just to give some examples. If your looking for plinking, buy quality cheap ammo like Federal AE and buy which ever is cheaper(hard to say that when ammo prices are through the roof), most of your practice shooting is before the shot is fired anyway if your looking for defensive rounds try some 20rnd boxes of various quality jhp ammo, maybe stick with specific type and try the different weights, what ever shoots best for you use. After some time you decided that there is a plinking ammo you specifically like and you just buy some bulk when you can.

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Everyone is trying to get all scientific about this but it is almost never that way. When you play with pressures and weights and powders you can predict to some extent what is going to happen but then there are subjective things like how the gun feels and snaps and rolls which are all personal preferences.

 

I prefer to compare this with tuning a car. The different between 165 and180 is about 9%. Now think what 9% more power can do to how a car drives, or think or 9% stiffer suspension, or 9% more camber. What would a 9% lighter car feel like with the same horsepower? What would lowering the car by 9% do to driving characteristics. 9% percent stickier tiers? 9% fuel economy? None of those single things will tell you how the car will behave. 9% more power might be awesome unless your transition can't handle it. 9% stiffer suspension my break your back, 9% lighter might mean your don't have enough weight on your front tiers and steering sucks, etc, etc

 

My point with this is that sometimes 9% can make a huge difference but not always in a predictable way depending how the rest of the system reacts and what your preferences are.

 

As a rule of thumb heavier bullets are slower and have a softer slower recoil. But not always, for example I have some 200gr 40 S&W ammo that boogies at 1050ft/s out of a four inch barrel, which is way above most factory 10mm loads.

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Here's the basics.

 

The faster you are pushing a lighter bullet, usually the louder the bang compared to something heavier and slower. Powder affects this, but it generally trends that way. This increased noise is perceived by many as more recoil. The smaller the bullet diameter and the higher pitched it gets. High frequency is more painful earlier than low frequency. Hence take the 40 s&w vs the .357 sig, and most people will find the sig to be much more abusive to the ears and flinch inducing.

 

For the same velocity, a heavier bullet will feel more pushy, and a lighter bullet will feel more snappy. The heavier bullet will also impart more torque to the gun as it goes down the barrel.

 

It's very subjective. Even given the same energy at the muzzle, the two bullets will cause different disruptions in the sight picture and you may have a preference.

 

If you load your own, lighter is cheaper and you can play a lot with powders to get what you want, light or heavy.

 

From an ammo designing standpoint, you need less of a velocity bump with a lighter bullet to get more penetration as velocity counts more to the total energy than mass does.

 

FOr commercial bulk FMJ ammo, the reality is that they are probably going sub-optimally slow in 40 with both weights, use slow burning powder to stay away from pressure thresholds, and will be far from the best experience you can get out of either. The delta between plinking 180 and quality self defense 180 is likely to be less than the difference between plinking 165 and quality SD 165. Chekc the published velocities of the bulk you are buying vs. the good stuff, it can vary. But usually the bulk 180 is closer to the feel of SD 180 for practice purposes.

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Have reloaded in all, and access to a chrono...

 

Most commercial 180 grain ammo I have shot was between 970 and 1050 fps out of a standard 5" gun. (we tested out of my SVI 2011 and a Tanfoglio/EAA witness)

 

My own reloads, I load 180 grain bullets at around 930/935 fps.

 

Every gun will be different, however as others mentioned, heavier bullets will often feel less snappy to shoot, but as vlad pointed out, it is all preferance.

 

Most guys in matches (idpa/uspsa) who shoot a 1911/2011 will shoot 180 grains out of a 5". I know a few shooting 200 grain lead bullets at lower velocities. At nationals, the trend was for guys with 6" guns to shoot 165 grain bullets at faster velocities (1" more of barrel). They preferred a bit more velocity to cycle the heavier, long slide faster.

 

end of day... try it out of your guns and see. In plastic fantastic guns.... almost any 40 cal commercial load will suck to shoot.

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